Written by W. Curtis Preston
Saturday, 10 March 2012 07:25
I don't care if you use disk, tape, or the cloud to back up your systems. (In case you think I'm swayed by advertising, I have advertisers from all of those categories.)
Having said that, it bothers me when I see misinformation being used to sway you one way or the other. This is why I wrote this article that disproved the Gartner 71% tape failure "quote," and this article disproving the Yankee Group 42% failure "quote." And since he used my comment system to link to his article, I also thought I'd write this blog article dispelling the misinformation in the article he linked to.
He said it's been a long time since people have seen tape used for backups.
The live survey of the hundreds of attendees to last year's Backup Central Live shows showed that 82% of them still use tape as their final destination for backups. So much for not seeing tape in a while.
He said IT pros are still skeptical that removable drives have a legitimate place in backup
Yes, we are. I think that 3.5" removable disk drives are a very bad place for backups. 2.5" drives yes, 3.5" drives, not so much. They're simply not designed for excessive portability. Adding to that is this fact: every portable hard drive I have ever used for backing up my laptop has died long before the drive it was backing up. Every single one.
He said cloud backup is shiny and new and that's why people are choosing it.
No, it's because it's a complete and total outsourcing of backup functionality. Backups can be onsite and offsite without ever touching a disk drive or tape drive. AND you will be constantly notified if your backups are working or not working. You often even get notified even if you shut off all your backups! That's not the case with any backup software product that I've ever used. There are a lot of reasons to use cloud backup over removable disk drives or tape. In fact, there are so many that I strongly recommend cloud backup for small to medium sized companies.
He said disk is cheaper for small companies
Yes, it is. It is cheaper to acquire the drives as long as you never need to add capacity. If you do, however, need to add capacity, disk costs will double. Tape costs will not. It'll cost you about $.02/GB to add more capacity to a tape-based system. (Having said that, I do not recommend backing up directly to tape; I haven't in a while.) Having said that, I priced a slightly different tape-based system than the one he quoted in his article, and it was approximately the same cost.
As to comparing their 10-bay disk systems against an autoloader, I don't see how you can do that. Backup software products simply don't know what to do with 10 removable disk drives, but they do not what to do with autoloaders. (I'm sure he knows a backup software product that will work his configuration, but I don't know of one.)
He said disk is more reliable than tape
Baloney. I've written about this before. Tape has a much higher reliability rate than SATA disk -- one hundred times more reliable. I've already shown above that the statistics he quotes in his article are bunk. Almost every failure I've ever seen with restores was the fault of anything but the media that was being used. (I still don't think tape should be used as the initial target for backups, but it is a very reliable place to put the second copy.)
He said LTO-5 speed is 140 MB/s, but only with compression
Sorry, Charlie. That's the native speed. It's up to 280 MB/s with compression. With the 1.5:1 I see all the time, it's 210 MB/s easy. Having said that, it's very hard to feed data to a drive that fast. This is why I don't recommend tape as the initial target for backups. But if you've already made a copy on disk, you should have no problem streaming that tape drive.
He said single file restores are faster from disk
Yes, they are. That extra minute it takes the tape to load and get to the single file would probably put most companies out of business. Seriously, you're going to make a case out of a minute of tape loading time?
He said upgrading/replacing is cheaper with disk
Are you kidding me? I addressed this already. If you need more capacity than the initial purchase, it's much cheaper to expand a tape system. Most customers go years without upgrading their drives.
He said doing synthetic fulls is easier on disk
Yes, it is. And CDP and CDP-like tech is also only possible on disk. Disk has a lot of things going for it.
He said tape has to be replaced more often
Again, baloney. A tape that is used once a week will last four years with the chart quoted in the article. That is longer than most disks I've used.
I don't recommend using tape as the initial target for backups, but I still think it's a great place to put the next copy. And if you are a smaller company, I think the best thing you can do is to use a cloud backup service that totally automates everything, and alllows for a local copy of your data. But I think that any backup system that requires small companies to manually swap removable media just to make backups happen is a bad idea.