Another example of why we do backups

There’s a story going around about Apple’s MacOS APFS sparse disk images occasionally losing their mind and throwing documents out the window.  Yet another example of why we do backups.

Don’t use APFS images for backups

I’ve never liked these disk images that Apple makes –– as a backup method.  This is just another example of why.  For those unfamiliar with them, they’re like a fancy .ISO image.  It’s one big file that you can mount as a file system. The “sparse” part is what the industry would call a thin-provisioned version of this image.  That is, you tell it how big it’s allowed to grow, but it will only consume the amount of space that is actually put into the image.

The problem that was recently discovered is that if the APFS sparse image runs out of virtual space, it will just keep writing the files like nothing’s wrong.  Even worse, the files will appear to have been copied, as they’ll be in RAM.  Unmount the disk image and remount it and you’ll find that the files were never copied.  Surely Apple needs to fix this.

The one place you’ll see a disk image is if you buy a Time Capsule Time Machine backup appliance.  I’m not sure why, but they chose to do it this way, instead of just mirroring the filesystem, the way Time Machine does on a local machine.  I’m sure they had their reasons, but this is where you’ll see disk images.  (Actually, I haven’t looked into the details of the Time Capsules in a while, so they could have changed.  But I can’t think of any other place where you’d see such a beast.)

I’ve never been a fan

Nine years ago I wrote an article about how I wasn’t a huge fan of Time Machine, and how I really didn’t like Time Capsules because of their disk images — and how they can get corrupted. Time Machine is nice for upgrades or a local copy, but I don’t think you should rely on it as your only backup.

This is why we do real backups.  Real backups are scheduled and happen all the time without you having to do anything. Their data is stored somewhere else, which today typically means the cloud. I simply can’t think of another viable way to backup mobile users and home users.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

Protect your backups from ransomware

Don’t get your backup advice from security people. That’s how I felt reading what started out as a really good article about protecting your systems from ransomware.  It was all great until he started talking about how to configure your backup system.  He had no idea what he was talking about. But now I’m going to give you security advice about your backup system, so take it with a grain of salt.

Windows backup servers are risky

Windows-based backup products that store data in a directory are a huge security risk. In fact, many customers of such products have already reported my worst fears: their backups were encrypted with the same ransomware that infected their servers.

This isn’t an anti-Windows rant, or an anti-BackupProductX rant. It’s simply acknowledging the elephant in the room.

  1. If your backup server is accessible via the same network your computers are on, it can be attacked via the same things that attack your computers.
  2. If your backup server runs the same OS as your computers – especially if it’s the OS that most ransomware attacks happen on (Windows) – it can be infected with the same ransomware
  3. If your backups are stored in a directory (as opposed to a tape drive, an S3 object, or a smart appliance not accessible via SMB/NFS), they can be infected if your backup server is infected.
  4. If your backups are stored on a network mount via NFS/SMB, you’re giving the ransomware even more ways to attack you.

What should you do?

I don’t want to be guilty of doing what the security guy did, so I’ll say this: research what you can do to protect your systems from ransomware. But I’ll do my best to give some general advice.

I know the best advice I’ve read is to keep up-to-date on patches and to disable Remote Desktop Management on Windows.  There are also default SMB shares in Windows that should be disabled.

You can also make sure that your backups aren’t just stored in a directory. Unfortunately, that’s the default setup for most inexpensive backup software products. You need to investigate if the software you’re using supports another way to store backups.  If not, it’s time to think about a different product.

The same goes true for those currently storing backups on an NFS/SMB share. Investigate if your backup software has the ability to store backups on that device without using NFS/SMB. If not, make sure you lock down that share as much as you can. Again, if not, it’s time to think about another backup product.

Consider a cloud data protection service

A true cloud-based data protection service might be the best way to do this.  In a true cloud-based system, you never see the backup servers. You don’t know what they are and never login to them. You login to a web-based portal, and the actual servers that make this happen are completely invisible to you.  (Similar to the way the servers that make happen are invisible to you.)

If your backup servers are invisible to you, they’re invisible to your attackers. If there’s no way to directly access your backup – unless you’ve specifically setup such access for a recovery or DR test – then ransomware can’t get to those backups either.

It should go without saying that this recommendation does not apply if your “cloud” data protection vendor is just putting backup software on VMs that you manage in the cloud – what many have dubbed “cloud washing.” If you’re seeing your backup servers as VMs in the cloud, they’re just as much of a risk as they are if they were in your data centers. It’s on the reasons why these cloud washing vendors aren’t really giving you the full benefit of the cloud if all they’re doing is putting VMs up there.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

Time to fire the man in the van

The man in the van can lose your tapes.  Any questions?

It’s the man, not the mountain

Yes, Iron Mountain has had many very public incidents of losing tapes. You can do a google search for Iron Mountain Loses Tapes to see what I’m talking about.  When all these stories started hitting the news back in 2005 (thanks to California’s new law requiring you to report such things), Iron Mountain’s official response was, “Iron Mountain performs upwards of five million pickups and deliveries of backup tapes each year, with greater than 99.999% reliability. Nevertheless, since the beginning of the year, four events of human error at Iron Mountain resulted in the loss of a customer’s computer backup tapes. While four losses is not a large number in comparison to an annual rate of five million transportation events, any loss is important to customers and to Iron Mountain … Iron Mountain is advising its customers that current, commonly used disaster recovery processes do not address increased requirements for protecting personal information from inadvertent disclosure.”

The tape vaulting company I used to use back in the day lost one or two of our tapes a year.  We gave them about 50 tapes a day, and retrieved 50 more back.  We tracked each individual tape, and were linked into their system to show when the tapes made it into the vault.  Every once in a while, there would be a discrepancy where one of the tapes would not show up in the vault.  This resulted in a search, and inevitably the tape would be found somewhere along the way.  Good times.

I remember one vaulting customer that received a box of tapes that weren’t theres.  When they called their rep, they had him read the bar codes off the tapes.  They couldn’t figure out whose they were, so the vaulting company said they should keep the tapes!

As long as media vaulting companies employ humans to be the “man” in the van, this problem will continue.  Humans do dumb things.  Humans make mistakes. So until these companies start hiring robots to pick up and deliver tapes, we will continue to see these problems.  However, I think much of the world will have moved to electronic vaulting by then.

I’ve always liked electronic vaulting

If you’re not going to use tapes to get your data offsite, you can use electronic vaulting.  This can be accomplished via a few different methods.

Onsite & Offsite Target Dedupe Appliance

There are a number of vendors that will be happy to sell you an appliance that will dedupe any backups you send to it. Those deduped backups are then replicated to another dedupe appliance offsite. This has been the primary model for the last 15 years or so to accomplish electronic vaulting. The problem is that these appliances are very expensive, and you have to buy two of them – as well as power, cool, and maintain them. It’s the most expensive of the three options mentioned here.

Source dedupe to offsite appliance

It makes more sense to buy backup software that will dedupe the data before it’s sent to an appliance. This appliance can be offsite, so that data is immediately sent offsite.  It can even be a virtual appliance running as a VM in the cloud.  Most people exploring this option opt for an onsite copy that replicates to the offsite appliance or VM.  Most vendors selling this type of solution tend to want to charge you for both copies.

Source dedupe to a cloud service

If you are backing up to a true cloud service (not just backup software running in some VMs in the cloud), and you are deduping data before it is sent to the cloud. Vendors that use this model tend to only charge you for the cloud copy. If they support a local appliance for quick recoveries, they tend not to charge for that copy. That makes this option the least expensive of the three

Fire the man, get a plan

Wow, I like that!  There are a number of ways you can now have onsite and offsite backups without ever touching a tape or talking to a man in the van down by the river.  Look into them and join the new millennium.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

The Perils of Hardware

No one likes hardware; they only like what they can do with it.  And I say this as a geek who has built plenty of PCs in my house, including a Hackintosh.  What kind of sick weirdo builds their own Mac?  Well, you know what? That Hackintosh illustrates the perils of hardware in three ways.

Hardware gets marked up

The first peril of hardware is why I did this: Apple’s crazy markup on hardware. Why did I go through the difficulty of finding and buying components that were compatible with MacOS?  Why did I go through the rigmarole necessary to fool the MacOS installer into installing on something that wasn’t a real Mac?

I wanted to run MacOS on a server powerful enough to run Adobe Premier Pro well, and the MacPro I wanted was something like $4-5000.  But I could build a Hackintosh for around $1500, so I did.

This is why storage customers revolted against traditional proprietary storage vendors in favor of software-defined startups that allowed them to use off-the-shelf hardware that wasn’t ridiculously marked up.  People started realizing that hardware is hardware, and rarely is hardware special enough to warrant a huge markup.

Hardware must be maintained

Hardware breaks.  Power supplies die, disks stop spinning, and fans stop blowing. This is why every production piece of hardware typically comes with a service agreement specifying how quickly the vendor should respond when a problem occurs.

At no time is this peril more acute than the last few weeks. The spectre of the Spectre and Meltdown vulnerabilities is wreaking havoc on hardware land. First Intel came out with a new microcode version to address the vulnerabilities, then Microsoft, RedHat, and other Linux vendors came out with OS patches.  Then people that installed them started seeing spontaneous reboots. So they all started pulling their patches, and Microsoft even released an out-of-band update that disabled the microcode patches if you installed them.  It’s been a tough couple of weeks for those that must maintain hardware.

Meanwhile customers who are using services like, Office365, Gmail, and yes, the Druva Cloud Platform, didn’t have to worry about maintaining the hardware underneath those systems. The service providers had plenty of work to do, for sure. The cloud is not magic. There is no such thing as the cloud; it’s only someone else’s datacenter. But people who were using true cloud services simply didn’t have to worry about maintaining the hardware behind the services they were using.

This brings me to the point of the companies in the data protection space who have now certified that their product runs in AWS. Yes, this allows them to say that they work “in the cloud.” But it’s important to distinguish this from a cloud service offering, where hardware is not your problem. Customers of such backup solutions that are “running in the cloud” are having just as many problems with their cloud backup servers as they are with their onsite servers.  Because even virtual hardware has to be maintained. It may be someone else’s hardware (i.e. you don’t own the server your cloud VM is running on), but you still have to maintain it.

Hardware is a capital expense

The Hackintosh I built was only $1500, but what if it had been $100,000?  Hardware of all kinds requires a significant amount of capital outlay.  Maybe you can finance it and maybe you need to come up with the actual cash to buy it outright.  Either way, it’s going to stay on your books for years.

Capital expenses can be really difficult to get approved. I remember working at a place where every single item over $1,000 was a capital expense, and getting capital expenses approved took months – even years.  I remember doing all sorts of things to work around that issue.

Real hardware also exists.  If you bought it for a project that changed directions, you’re stuck with that hardware.  If your project needs faster hardware, you have to upgrade – leaving the old hardware in the dust (literally). This is perhaps the most compelling thing about moving apps to the cloud.  If you change your mind, you just delete the VM.

The hardware isn’t important – the service is

This brings me full circle. The hardware isn’t what’s important; the service is what’s important. Consider my opening story of the Hackintosh. My need was to edit video. The solution to that need was Adobe Premiere Pro – which I already owned.  But I owned the MacOS version, so I needed a Mac.  I couldn’t afford a MacPro, so I built one. (I just found out the Hackintosh I built is running fine, BTW.)

But what if I was able to find a cloud service to do my video editing? Yes, I realize there are rules of physics that might get in my way, since raw video can be huge. But just work with me.  What if I could meet all of my business needs with a service that runs in the cloud?

Would I need the Mac?  Would I need the Hackintosh? Would I need Premiere Pro? No, i wouldn’t.  A Chromebook would probably do just fine.

But if I went to Apple and told them my business requirements, their answer to my questions would most certainly be a MacPro. That’s what happens when you ask a hardware vendor to help solve your problem. It’s like going into a hardware store and telling him you need a place to live. The first thing they’re going to do is sell you a hammer, nails, and wood.  Because that’s what they sell.

Why would you want hardware?

This entire blog post was inspired by another blog post by a blogger and writer I respect. The title also started with “The Perils of…” He used the hammer analogy, too. He suggested that you shouldn’t go to vendors who just sell “backup,” as there is an entire continuum of data protection requirements not met by that term.  I agree with that part.  The days of backup only are over.

But then he suggested that his company, a very large hardware and software vendor, was the right way to go because they sell all types of solutions. That’s where I’m going to have to disagree. Because almost all of their solutions are just more hardware & software.  Hardware & software get marked up.  It has to be maintained. And hardware is a large capital investment.  Why would you want to do any of that if you could meet your data protection needs with a service where none of that is an issue?  Just a thought.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

Instant recovery & dedupe are not friends

Instant recovery is the modern-day equivalent of what we used to call a hot site, as it allows you to recover immediately after some type of incident. I have personally advocated for this concept, as I strongly believe that in a true disaster (or ransomware event), time is of the essence.

As mentioned in my previous article, one company’s lack of an instant recovery system caused them to pay the ransom when they were infected with ransomware. They said recovering their entire datacenter using their backup system would have taken several days, and paying the ransom would cost less than several days of downtime. I explain in the article why I completely disagree with this reasoning, but I understand I have the luxury of Monday morning quarterbacking.

The key to being able to easily recover from a large disaster or ransomware attack is to be able to instantly spin up your entire datacenter in a hot site or an instant recovery system. This allows you to take your time addressing the cause of the incident, such as identifying and removing the ransomware itself, putting out actual fires, or replacing hardware damaged in the incident. If you can run your entire environment in a public or private cloud, you can continue your business – almost without interruption – regardless of how bad the incident is.

Dedupe is not instant recovery’s friend

Instant recovery is great, as it is allowing many to recover much quicker and better than they ever could before. Deduplication is also great, as it is the technology that enables so many wonderful things, like disk-based backup and recovery, offsite replication of backups without human intervention, and significant reductions in bandwidth usage. It’s the marriage of deduplication and instant recovery that usually doesn’t work.

Deduplication systems are very good at many things, but usually are not very good at random reads and writes. Just ask anyone who has attempted to run one or more VMs using their deduplicated backup data as the datastore. The performance might be enough to handle a single server that doesn’t require a lot of random I/O, but running several servers or an entire datacenter simply isn’t possible from a deduplicated datastore.

This is why post-process deduplication backup appliances make such a big deal about their native landing zone where recent backups are stored in their native, non-deduplicated format before they are deduplicated for replication or long-term storage. They advise customers who are interested in instant recovery to turn off any backup software dedupe.  Backups are sent to disk in their full, native format and are stored that way in the landing zone until they are pushed out by newer backups. This yields much better performance if you have to run multiple VMs from your backups.

But most people using the instant recovery feature tend to be using modern backup packages that already have deduplication integrated as a core part of their product. This means they are typically performing their instant recovery using a deduplicated datastore. This means that they should be able to recover one or two VMs at a time. However, they will probably be very disappointed if they try to recover their entire datacenter.

There are other ways to do instant recovery

If you are going to use instant recovery to run your entire datacenter in a disaster, the latest copy of your VM backups needs to be in native format on storage that can support the performance that you need. There are a couple of ways of accomplishing that.

Continuous data protection (CDP) products are essentially replication with a back button. Some of these companies describe themselves as a TiVo for your backups. They store your backups in native format, and also store the bits needed to be able to change portions of the latest version in order to move it back in time. (A good example of such a product would be Zerto.)

These types of products tend to do well at disaster recovery, but not at operational recovery. They’re good at recovering an entire datacenter, usually not so good at recovering a single file.  The DR functionality of these products can be quite advanced, as it is their specialty. Another upside of this approach is you only have to pay for one copy of your backup – plus the versioning blocks of course. One downside to this approach is most people also purchase another product for operational recovery.

Alternatively, you can use a backup product that uses its backups to update an image stored in native format as a DR image.  (Druva offers this as part of their Data Protection as a Service offering.) Instant recoveries – especially large scale recoveries of an entire datacenter – would run from this DR image. The advantage of this approach is you get operational recovery and disaster recovery in a single system. This is both simpler and less expensive than maintaining two systems. One disadvantage is that you will need to pay for the storage the DR copy of your data uses, equivalent to one full backup.  This cost is offset by the fact that you would be able to do both operational recovery and disaster recovery with a single product.

Don’t pay ransoms! Get a better backup product!

As I mentioned in my previous blog post, please prepare now to be able to recover from a ransomware attack or other disaster. Investigate the DR plans of your company, as you might need to activate them for something you might not consider a disaster. Your entire datacenter may be fully functional, but you won’t be able to get to your data if it’s all encrypted.  So make sure you have a solid plan for how you would recover from this scenario, because the likelihood that this will happen to your company goes up every day.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

Do not pay ransomware ransom!

You don’t negotiate with terrorists, and you don’t pay ransom unless you have no other choice. Even then, you should try every available avenue before you decide to pay money to the company holding your data for ransom.  It’s just a bad idea. Last week there was a news story of a company that paid several BitCoin (each of which was worth roughly $15K) to get their data back. (I am not putting the exact amount or link to the story for reasons I will explain later.)

This kind of thing has become all too common, but this time things were a little bit different. The company disclosed that they had backups of the data that they could have used to restore their environment without paying the ransom. They chose to pay the ransom because they felt that it would restore their data quicker then their backup system would be able to do. I have two observations here: that was a really bad idea, and they should have had a better backup system.

You don’t pay ransom or blackmail!

The biggest reason you do not pay ransom or blackmail is that it says you’re open to paying ransom or blackmail. There is absolutely nothing stopping the entity who attacked you from doing it again in a few days or weeks.

Just ask Alexander Hamilton. Yes, that Alexander Hamilton. He had an affair with a married woman and was subsequently blackmailed by her husband. Mr. Reynolds started out asking for small figures, amounting to a few hundred dollars in today’s money.  But by paying a few hundred dollars, Hamilton showed that he was open to paying ransom. If he was open to paying a few hundred, he would pay a few hundred more. Reynolds came back for money several times.  By the time the event came to a conclusion, Hamilton had paid Reynolds roughly $18,000 in today’s money. (And the affair eventually came out anyway.)

By paying the BitCoins to the black hat, this company has shown that they will pay the ransom if they are attacked. What makes matters even worse is that the event was published in the news. Now everyone knows that this company will pay a ransom if they are attacked. they might as well have put a giant “HACK US!” sign on their website. (The first version of this story included the name of the hospital and a link to the story. I took it out so as not to add insult to injury.)

They didn’t just paint a target on their back; they painted a target on every companies back. The more companies that pay the ransom, the more black hats will attack other companies. If we all collectively refuse to pay the ransom – after ensuring that we can recover from a ransomware attack without paying the ransom – these black hats will find some other way to make money.

Another reason that you do not pay ransomware companies any money is that you are dealing with unscrupulous characters, and there is no assurance that you will get your data back. I am personally aware of multiple companies who paid the ransom and got nothing.

They need a better backup system

The backup system must not have been designed with the business needs of the company, or it would have been able to help them recover from this attack without paying the ransom. According to the story, the company felt that restoring from a backup would take too long, and paying the ransom would be quicker. What this tells me is that the recovery expectation was nowhere near the recovery reality.

This company must have done a cost-benefit analysis on the cost of a few days of downtime, and decided that the amount of lost revenue was much greater than the cost of paying the ransom. Let’s say, for example, they calculated that everyday of downtime would lose them one million dollars. If they used their backup system to restore their data center, they would lose more than three million dollars, since they said it would take 2-3 days. $55,000 is peanuts when compared to three million, so they paid the ransom. I do not agree with this logic, as I discussed previously in this article.  But this is the logic they apparently used.

If they knew that their company would lose a million dollars a day, then they should have designed their backup or disaster recovery system to be able to recover in less than a day. Technology certainly exists that is capable of doing that, and it usually costs far less than the amount of money that would be lost in an outage.

Even if the system cost similar to the amount of money that would be lost in an outage, it still might make sense to buy such a system. The reason for this is the impacts to the business go beyond a straight loss of revenue due to downtime. If your business suffers a sustained outage, you may lose more business than just the business you lost while you were down. You might lose some customers for good, and the lost revenue from that would be difficult to calculate.

Being ready for a disaster

If minimizing downtime is the key, the only way to truly be ready for a disaster is to be able to boot instantly after an outage. There are a variety of products that advertise such functionality today, but very few of them would be able to recover an entire datacenter instantly. I will discuss the various instant recovery options in my next blog post.

For now, I just want to remind you of two things: be ready for ransomware, and never pay the ransom. Make sure you are able to recover all of your critical data in a time frame that your business would find acceptable, so that you can tell any ransomware black hats to go pound sand if they come knocking on your door.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

Addressing Spectre/Meltdown in your Backup System

Your backup server might be the biggest vulnerability in your datacenter, as I already discussed in my previous blog post. Which means that you should have patched it first, but I’m betting that you haven’t patched it yet. If you don’t know why I feel this is a problem, go check out the previous post.

How are you responding to the Spectre & Meltdown vulnerabilities with regards to your backup infrastructure?  What kind of week you’ve had depends on what type of backup infrastructure you have.

Bare Metal Backup Server

This includes bare-metal Linux & Windows servers, and backup servers running in VMs in the cloud. You need to find the appropriate patches for your backup server’s OS, test them, and install them.  Here’s a good list of those patches. I’m guessing you probably don’t have the time to test them to see what kind of performance impact they might have on your backup system.

Reports of the performance impact of various patches include everything from “no noticeable impact” to “50% performance loss.”  Unfortunately for you, it seems that the more I/O intensive your workload, the greater the impact on performance. So you might install (or have installed) the patches and then run/ran your next set of backups — only to find out that they don’t complete anywhere nearly as fast as they used to.

If that’s the case for you, then you’re having to figure out how to respond to this performance loss. If your backup server is running in a VM, you might be able to just upgrade to a bigger VM.  You’ll have a little downtime, but that’s a small price to pay.

If you have a bare metal server, which is far more likely, you might find yourself in a situation of needing to do an emergency upgrade to the backup server.  Some systems run in a cluster and can be scaled by just buying another node in the cluster, but others will require a forklift upgrade of the backup server.  Either way, you may be looking at an emergency order of a new server or two. In short, you might be having a very difficult week.  It’s a good week to be a server vendor, though.

Virtualized Backup Server

If your backup server is running inside a VM, you’ve had even more interesting week. In addition to everything mentioned above, you also need to deal with microcode updates from VMware or Microsoft.

VMware got a lot of credit for responding to Spectre/Meltdown very quickly, as they issued patched pretty quickly. Unfortunately, the patches were apparently causing spontaneous reboots, so they pulled them almost as fast. Check out this page for the latest info on this.

Once these patches are available again, you’ll need to test and install them. And, of course, you will also need to patch the guest operating systems just as you would if they were bare metal.

Hyper-V customers need to do the same thing.  Here’s the latest information from them.

The performance impact of these patches is no more known than the performance impact of the previously mentioned OS patches. Which means you might find yourself having to upgrade the underlying hardware, or at the very least increasing the power of any VMs to compensate for the performance loss.  Again, it’s a good week to sell servers, not such a good week for those buying them.

Cloud-native Backup Service

If you are using a cloud-native backup service, you don’t have to do anything.  A cloud native service means you are not responsible for the VMs offering such a service. Those VMs are not your problem.  The most you might want to do is contact your backup service vendor and ask them if they have patched their systems to address any vulnerabilities.

When the backup service installs the appropriate patches in the backend, there might indeed be an impact to the performance of each VM. But if it’s a scalable cloud service, it should be able to easily compensate for any performance loss by adding additional compute resources.  This should not be something you should have to worry about.

Cloud means never having to say you’re sorry

A true cloud service should not require you to have to worry about the infrastructure.  (Which is why I feel the word “cloud” does mean something, @mattwbaker.) There are other backup systems out there that are actually quite good – but they’re not cloud native. If your backup app requires you to create VMs in the cloud to install your backup server software in, they’re not really a cloud app.  They’re cloud washing. (Honestly, taking a product designed for physical nodes in a datacenter and installing it in VMs in the cloud is a perfect example of how not to use the cloud.)

If your backup service is actually a cloud backup service, you should not have to worry about the security of your backup system – it should be automatically taken care of.  If you’re having to take care of it, perhaps you should consider a different system.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

Your onsite backup server is a security risk

Did you know there have been 7870 public data breaches since 2005?  Your company’s data is under attack. Like terrorism, the attackers only have to be successful once. You have to be successful 100% of the time.

Which is why its important to patch your systems regularly and keep abreast of any security vulnerabilities your company’s backup product may have.  But have you ever thought about how much of a security risk the backup server is? It’s a risk for three reasons: the value of what it has, the typical experience level of its admins, and lack of attention.

The backup system has all the marbles

Did you ever think about the fact that the backup system is the most sensitive server in your environment? It’s sensitive because it has everything and it can do everything.

First, the backup system has a copy of everything! All the data in your environment resides on disks or tapes it controls. While some data may be stored offsite and is effectively out of reach, most current data is immediately available via a few simple commands. Sometimes the backup data is available via other mechanisms, such as a web or NFS server, which is why a vulnerability in those products could give a malicious user access to anything he/she wants.

The backup system can read and write every piece of data in your datacenter. In order to backup data, it must be able to read it.  To be able to read it, the backup system is given superuser privileges.  Unix/Linux backup software runs as root, and Windows systems tend to run as Administrator. That means it can read or write any file in the environment.

Most backup software also has the ability to run scripts before and after the backup, and those scripts run as the privileged user. Combine that with the ability to backup and restore files, and you have a scary situation.  A malicious user that gains backup admin privileges can write a malicious script, back it up, restore it to the appropriate location, then execute the script using a privileged user.  Just let that sink in for a minute.

The backup admins are often very junior

My first job in tech was the “backup guy” for a huge credit card company. I barely knew how to spell Unix, and a few days into my job I was given the keys to the kingdom: the root password to the backup system and every server in the datacenter.  (We didn’t have the concept of role-based admin in those days, so anything you did with backups, you did as root.)

My story is not unique.  Backups are often given to the FNG. He or she takes the gig because it gets them the job, but it’s the job that nobody wants. As soon as you get some experience under your belt, they do their best to pass off this very difficult job to anyone else.  This has been true of backups for years, and this revolving door usually results in very junior people running the backup system.

I know I wanted to get out of backups back then, but I went from being the backup guy to being in charge of the backup team.  Three years later, I was still the main point of contact for the backup system.  Working for me were several people who were just as junior as I was when I started, all of whom had root privileges to the entire bank. Without going into details, I’ll just say that not everyone that worked for me should have been given the keys to the kingdom like that.

The most sensitive system in your environment is being handed over to the most junior person you have.  Again… let that sink in a little bit.

The backup server doesn’t receive enough attention

The security team always made sure the database servers & file servers were patched. But I don’t recall ever getting a call from them about the backup server. That meant it was up to the most junior person in the environment to make sure the most sensitive server in the environment was being regularly patched and secured against attacks.  That makes perfect sense. Not.

Another way this manifests itself is in the backup software. Many companies making backup products rely on external products (e.g. Apache) to augment their functionality (e.g. web access to your backup server). The thinking is to use publicly available tools instead of building their own. They’re a backup company, after all, not a web server company.

But unfortunately, embedded software like this often gets patched later than it should.  When an Apache vulnerability is discovered, people who know they are running Apache tend to patch it.  But what if it’s inside your backup software?  You rely on the backup vendor to know that and to patch it appropriately. But the inattention I’m referring to also sometimes applies to embedded components inside a backup system. It make take weeks or months before the vulnerability is patched in the backup software. This ArsTechnica article discusses a recently patched vulnerability in a backup software package where there was a three month delay between the initial discovery of the vulnerability and the creation of a patch for all related systems.

Choice 1: Secure your onsite backup system

You can do a number of things to secure your onsite system, starting with recognizing how much of a vulnerability it is. You can harden the system itself, patch the backup system, and do your best to limit the powers of your backup admin.

Harden the backup system

Firewall it off, using a software firewall running in the system or an actual firewall in front of the system — preferably the latter. Make it so that you can only administer the system via a particular VPN, and that admins must authenticate to the VPN prior to administering the backup system. This also addresses another vulnerability, which is that some backup systems send their commands in plain text.

Make sure that the backup server is running the most secure version of the operating system you have.

Run the backup software via a separate privileged account, not the privileged account.  Run it with an account called backupadmin with userid 0, or with Administrator privileges.  Do not run it as root or Admininistrator.  Then use your ITD software to watch that account like a hawk.

If your backup admin needs root privileges on Unix systems, force them to use sudo.

Require Windows backup admins to use their non-privileged account, and “Run as administrator” when they need to do something special.

Make sure the backup system is continually updated to the latest patch level. It should be the first system you patch, not the last.

If your backup software supports two-factor authentication, use it.

If you are writing backup data to a deduplication appliance across Ethernet, you need to harden and separate that interface as well. For example, do not allow direct access to any of its data via NFS/SMB. A physically separate Ethernet connection between the backup server and any backup storage would be preferred.

Limit backup admin powers

If your backup system supports the concept or role-based admin, do whatever you can to limit the power of the backup admin.  Maybe give them the power to do backups but not restores.  Or they can run backups, but not configure backups.  Restores and configuration changes could/should be done by a separate account that requires a separate login with strong two-factor authentication.

Choice 2: Get rid of  your backup server

What if you got rid of your backup server altogether?  There’s nothing more secure than something that doesn’t exist!  You could do this by using a backup system with a service-based public cloud architecture. Backup services that backup directly to the cloud offer a number of security advantages over those that use backup servers.

Front end designed for direct Internet access

Traditional backup systems are designed to be run inside an already-secure datacenter, where there is an expectation that direct attacks will be lower. Cloud backup systems are designed with harder front ends because they acknowledge they will be directly connected to the Internet. A lot of the basic security changes suggested above would be considered table stakes to any Internet-facing service.

Continuous security monitoring

Backup services run in a cloud like AWS are continually monitored for attempted intrusion.  (Again, this is table stakes for such a service.)  You get best of breed security simply by using the service.

Any embedded systems constantly & automatically patched

The operating systems and applications supporting any backup service are automatically and immediately patched to the latest available patches. The infrastructure is so huge that this has to be automated; you don’t have to do anything to make it happen.

Backup data not exposed to anyone

A good cloud backup system also segregates your actual backup data from the rest of the network, just like I was suggesting for your onsite backup server. But in this case, that’s already one. No one is getting to your backup data except through the authorized backup system.

Summary: Lock it up or give it up

Once you recognize what an incredibly vulnerable thing your backup server is, your choices are simple: lock it up very tight or get rid of it. I think most companies would be served well by the latter.  Given the advent of really good dedupe and replication, only the biggest companies are not able to take cloud-based backup systems.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

Dedupe done right speeds up backups

On my LinkedIn profile, I posted a link to my last article, Why good dedupe is important — and hard to do.  I got some pretty good feedback on it, but one comment from my buddy Chris M. Evens (@chrismevans) got me thinking.

“Curtis, it’s worth highlighting that space optimisation may not be your only measurement of dedupe performance. The ability to do fast ingest with a poorer level of dedupe (which is then post processed) could be more attractive. Of course, you may be intending to talk about this in future posts…”

I’m glad you asked, Chris! (BTW, Chris lives over yonder across the pond, so he spells things funny.) Here’s my quick and longer answer to your question:

If dedupe is done right, it speeds up backups and doesn’t slow them down.

Target dedupe can slow down backups

I think Chris’ thinking stems primarily from thinking about dedupe as something that happens in a target dedupe appliance.  I have run backups to a number of these appliances over the years, and Chris is right.  Depending on the architecture — especially decisions made about dedupe efficiency vs speed — a dedupe appliance can indeed slow down the backup system.

slow down

This is actually why I traditionally preferred the post-process way of doing dedupe when I was looking at target appliances.  A post-process system (e.g. Exagrid) first stores all backups in their native format in a landing zone.  Those backups are then deduped asynchronously. This made sure that the dedupe process — which can be very CPU, RAM, and I/O intensive — didn’t slow down the incoming backup.

An inline approach (e.g. Data Domain) dedupes the data before it is every written to disk. Proponents of the inline approach say that it saves you from having to buy the disk for the staging area, and that it is more efficient to dedupe it first.  They claim that the compute power required to dedupe data inline is made up for by a significant reduction in I/O.

But I generally preferred the post-process approach for two reasons. The biggest reason was that it left the latest backup in its native format in the landing zone, creating a significant performance advantage during restores — especially instant recovery type restores. But the other reason I generally preferred target dedupe was the performance impact I had seen inline dedupe have on backups.

Chris’ point was that strong dedupe can impact the performance of the backup, and I have seen just that with several inline dedupe solutions. Customers who really noticed this were those that had already grown accustomed to disk-based backup performance.

If you were used to tape performance (due to the speed mismatch issue I covered here) then you didn’t really notice anything.  But if you were already backing up a large database or other server to disk, and then switched that backup to a target dedupe appliance, your backup times might actually increase — sometimes by a lot.  I remember one customer who told me their Exchange backups were taking three times longer after they switched from a regular disk array to a popular target dedupe appliance.

Target dedupe was — and still is — a band-aid

The goal of target dedupe was to introduce the goodness of dedupe into your backup system without requiring you to change your backup software. Just point your backups to the target dedupe appliance and magic happens.  It was a band-aid, and I contend it still is.

But doing dedupe at the target is much harder — read more expensive — than doing it at the source.  The biggest reason is that the dedupe appliance is not looking at your files; it’s looking at a “tar ball” of your files.  It’s looking at your files inside a backup container, many of which are cryptic and difficult to parse.  A lot of work has to go into deciphering and properly “chunking” the backup formats. That work translates into development cost and computing cost, all of which gets passed down to you.

The second reason target dedupe is the wrong way to go is that it removes one of the primary benefits of dedupe: bandwidth savings. With a few exceptions (e.g. Boost), your network sees no benefit from dedupe.  The entire backup — fulls and incrementals — are transferred across the network.

It was a band-aid, and it did a good job of introducing dedupe into the backup system. But now that we see the value of it, it’s time to do it right.  It’s time to start deduping before we backup, not after.

Source dedupe is the way to go

Source dedupe is done at the very beginning of the backup process.  Every new or modified file is parsed, and a hash is calculated for its contents. If that has has been seen before, that chunk doesn’t need to be transferred across the network.

There are multiple reasons why source dedupe is the way to go.  The biggest reasons are purchase cost, performance and storage & bandwidth savings.

Target dedupe is expensive because it is developmentally and computationally expensive. I used to joke that a target dedupe appliance makes 10 TB look like 200 TB to the backup system, but they’d only charge you for 100 TB.  Yes, target dedupe appliances make the impossible possible, but they also charge you for it.

They also charge for it over and over.  Did you ever think about the fact that all the hard work of dedupe is done only by the first appliance?  Therefore, one could argue that only the first appliance should cost so much more.  But you know that isn’t the case; you pay the dedupe premium on every target dedupe appliance you buy, right?  Source systems can charge once for the dedupe, then replicate that backup to many locations without having to charge your for it.

Source dedupe is also much faster.  One reason for that is that it never has to dedupe a full backup ever again. Target appliances are forced to dedupe full backups all the time, because the backup software products all need to make them once in a while.  A source dedupe product does one full, and block-level incrementals after that.  Another reason target dedupe is faster is that it can look directly at the files being backed up, instead of having to divine the data hidden behind a cryptic backup format.

Finally, because source dedupe is looking directly at the data, it can dedupe better and get rid of more duplicate data. That saves bandwidth and storage, further reducing your costs — and speeding up the backup.  The more you are using the cloud, the more important this is.  Every deduped bit reduces your bandwidth cost and the bill you will pay the cloud vendor every month.

Dedupe done right speeds up backups

This is why I said to Chris that this problem of being forced to decided between dedupe ratio and backup performance really only applies to target dedupe.  Source dedupe is faster, cheaper, and saves more storage than any other method.  It’s been 20 years now since I was first introduced to the concept of dedupe.  I think it’s time we start doing it right.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

Why good dedupe is important — and hard to do

Good dedupe creates real savings in disk and bandwidth requirements.  It also makes the impossible possible by replicating even full backups offsite. Dedupe is behind many advancements in backup and replication technology over the last decade or so.

duplicate data

What is dedupe?

Dedupe is the practice of identifying and eliminating duplicate data. It’s most common in backup technology but is now being implemented in primary storage as well.  Just as dedupe made disk more affordable as a backup target, dedupe makes flash more affordable as a primary storage target.  It also changes the economics of secondary storage for reference data.

The most common method of accomplishing this is to first chop up the data into chunks, which are analogous to blocks. We use the terms chunks, because blocks typically imply a fixed size of something like 8K. Dedupe systems often use pieces of variable size, so the term chunk was coined to refer to a piece of data to be compared.

The chunk is then run through a cryptographic algorithm such as SHA-256. Initially intended for security reasons, such algorithms produce a unique value for each chunk of data. In the case of SHA-256 (AKA SHA-2), it creates a 256-bit value we call a hash. If two chunks of data have the same hash, they are considered identical and one is discarded.

The more redundant data you can identify, the more money you can save and the faster you can replicate data across the network.  So what kinds of things make effective dedupe?

True global dedupe

The more data you can compare, the more duplicate data you are likely to find. Many dedupe systems create data pools that do not talk to each other and thus significantly reduce their effectiveness.

Some dedupe systems only look for duplicate data contained within the backups of a single system, for example.  They do not compare the files backed up from Apollo to the files backed up from Elvis. If your company has multiple email servers, for example, there is a very high chance of duplicate data across them, as many people will send the same attachment to several people that may hosted on different email systems. If you’re backing up endpoints such as laptops, the chances of duplicate data are significant.

On the opposite end of the backup equation are backup appliances. Target dedupe appliances — even the most well-known ones — typically compare data stored on an individual appliance. The dedupe is not global across all appliances.  Each target dedupe appliance is a dedupe silo.

This is also true when using different backup systems. If you are using one backup system for your laptops, another to backup Office365, and another to back up your servers, you are definitely creating dedupe silos as well.

A truly global dedupe system would compare all data to all other data. It would compare files on a mobile phone to attachments in emails. It would compare files on the corporate file server to files stored on every laptop.  It would identify a single copy of the Windows or Linux operating system and ignore all other copies.

Dedupe before backup

The most common type of dedupe today is target appliance dedupe, and it’s absolutely less effective than deduping at the source. The first reason it’s less effective is that it requires a significant amount of horsepower to crack the backup algorithm and look at the actual data being backed up. Even then, it’s deduping chunks of backup strings, instead of chunks of actual files. It’s deducing the underlying data rather than actually looking at it.  The closer you’re getting to the actual files, the better dedupe you’re going to get.

The second reason its less effective is that you spend a lot of CPU time, I/O resources, and network bandwidth transferring data that will eventually be discarded. Some dedupe appliances have recognized this issue and created specialized drivers that try to dedupe the data before it’s sent to the dedupe appliance, which validates that the backup client is the best to dedupe data.

The final reason why dedupe should be done before it reaches an appliance is that when you buy dedupe appliances, you pay for the dedupe multiple times. You pay for it in the initial dedupe appliance, and you may pay extra for the ability to dedupe before the data gets to the appliance. If you replicate the deduped data, you have to replicate it to another dedupe appliance that costs as much as the initial one.

Application-aware dedupe

Another reason to dedupe before you back up is that at the filesystem layer the backup software can actually understand the files its backing up. It can understand that it’s looking at a Microsoft Word document, or a SQL Server backup string. If it knows that, it can create slice and dice the data differently based on its data type.

For example, did you know that Microsoft Office documents are actually ZIP files?  Change a .docx extension to .zip and double-click it.  It will open up as a zip file. A dedupe process running at the filesystem layer can do just that and can look at the actual contents of the zip file, rather than looking at a jumble of chunks of data at the block layer.

How much can you actually save?


I try to keep my blogs on relatively agnostic, but in this one I feel compelled to use my employer (Druva) as an example of what I’m talking about. I remember seven years ago watching Jaspreet Singh, the CEO of Druva, introduce Druva’s first product to the US.  He talked about how good their dedupe was, and I remember thinking “Yea, yea… everybody says they have the best dedupe.”  Now that I’ve seen things on the inside, I see what he was talking about.

I’ve designed and implemented many dedupe systems throughout the years. Based on that experience, I’m comfortable using the 2X rule of thumb. Meaning that if you have a 100 TB datacenter, your dedupe system is going to need at least 200 TB of disk capacity to back it up with any kind of retention.

For clarification, when I say 100 TB, I’m talking about the size of a single full backup, not the size of all the backups.  A typical environment might create 4000 TB of backup data from a 100 TB datacenter, which gets deduped to 200 TB.  That’s why a good rule of thumb is to start with 2X the size of your original environment.

Imagine my surprise when i was told that the Druva rule of thumb was .75X.  Meaning that in order to backup 100 TB of data with a year of retention, Druva would need only 75 TB of disk capacity. That’s less than the size of a single full backup!

Since Druva customers only pay each month for the amount of deduped data that the product stores, this means that their monthly bill is reduced by more than half (62%.)  Instead of paying for 200 TB, they’re paying for 75 TB.   Like I said, good dedupe saves a lot of money and bandwidth.

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Architect at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.