Backup Central

Hello all,


I'm trying to get my head around exactly what and how a virtual tape
drive system works.

Here is how I see it: VTL is mostly a software product that allows me to
create virtual libraries and tape devices. I can then present those
devices to any host connected to the FC SAN. (I know that some offer
iSCSI but I only want to deal with Fiber in my example). Those virtual
tape drives get written to by NetBackup just like normal tape drives,
but the data really is stored on a central disk subsystem. Using NB
duplication, I can get the data off to real tapes to be vaulted for DR
purposes.

I guess the first idea that comes to mind is to place a virtual drive on
every SAN attached host and make them all SAN media managers (I know
that Veritas License Cost will make this sound crazy). I could then have
each SAN Media server write it's own data to it's local "Virtual" tape
drive.

Can someone who has a VTL system fill in the holes for me? I'm sure
there are many many more considerations but I'm just at the thinking
phase.


Thanks,

Kris

Kris,

Your general understanding of how VTL works is pretty much correct.
There are certain advantages to VTL which you have not mentioned such as "out
of the back end duplication" but if you need to keep an image on-site as well
as physical tape off site at the same time then you got it. As far as whether
to make any SAN attached host a media server depends entirely on your
configuration and what you need to back up off of these hosts. If the amount
of data is trivial, then it may be more efficient to back them up over the
network. You also need to consider that VTL, just as a physical tape library,
would require a separate SAN connection(s) for the tape drive(s) apart from
your existing SAN connections to the disks.

Depending on your configuration, you might consider using fewer
robotics contorol hosts (you can have different drives in a single robot
attached to multiple hosts). In our scenario it works great because we a)use
centralized duplication and b)have clusered robotics control hosts so our
chances of having a downed robot is very low.

Again, it all depends on what you are tring to do, what you currently
have and how much you are willing to spend.

paulg

Save On Jan 27, 8:33pm, Williams, Kristopher L wrote:
Subject: [Veritas-bu] Virtual Tape Library / Drives
Hello all,


I'm trying to get my head around exactly what and how a virtual tape
drive system works.

Here is how I see it: VTL is mostly a software product that allows me to
create virtual libraries and tape devices. I can then present those
devices to any host connected to the FC SAN. (I know that some offer
iSCSI but I only want to deal with Fiber in my example). Those virtual
tape drives get written to by NetBackup just like normal tape drives,
but the data really is stored on a central disk subsystem. Using NB
duplication, I can get the data off to real tapes to be vaulted for DR
purposes.

I guess the first idea that comes to mind is to place a virtual drive on
every SAN attached host and make them all SAN media managers (I know
that Veritas License Cost will make this sound crazy). I could then have
each SAN Media server write it's own data to it's local "Virtual" tape
drive.

Can someone who has a VTL system fill in the holes for me? I'm sure
there are many many more considerations but I'm just at the thinking
phase.


Thanks,

Kris

_______________________________________________
-- End of excerpt from Williams, Kristopher L

Paul,

I read about what I think you mean by "out of the back end duplication".
If I have it right, with certain subsystems you can run FC from the disk
straight to the tape library. The VTL is smart enough to know how to
duplicate images to the tapes. I guess the only thing I don't understand
is where NetBackup comes into play with that piece. Does NetBackup
somehow control the duplication process even though the data isn't going
through a media server? What I would want to avoid is using some other
software program to managed the duplication from the VTL to live tape
library.

As for the separate connection to the VTL, in our Windows environment we
currently have two FC cards in each SAN attached box. We have two disk
SAN's and connect one card to each for failover (Securepath). Currently
we just allocate tape devices through these two cards. For Windows, we
do not have a separate SAN for just tape. I know this would probably be
the best bet, but with the limited number of PCI card slots in most
newer servers, using 3 for FC cards just isn't possible.

I thought of one more question. Has anyone used VTL with NT 4.0? I know
it's a dieing breed, but not everyone is up to Win2k just yet.

Thanks,

Kris

-----Original Message-----
From: Paul Gimpelev [mailto:paulg < at > CDCNA.COM]
Sent: Thursday, January 27, 2005 9:50 PM
To: Williams, Kristopher L; List Veritas List
Subject: Re: [Veritas-bu] Virtual Tape Library / Drives

Kris,

Your general understanding of how VTL works is pretty much
correct.
There are certain advantages to VTL which you have not mentioned such
as "out of the back end duplication" but if you need to keep an image
on-site as well as physical tape off site at the same time then you got
it. As far as whether to make any SAN attached host a media server
depends entirely on your configuration and what you need to back up off
of these hosts. If the amount of data is trivial, then it may be more
efficient to back them up over the network. You also need to consider
that VTL, just as a physical tape library, would require a separate SAN
connection(s) for the tape drive(s) apart from your existing SAN
connections to the disks.

Depending on your configuration, you might consider using fewer
robotics contorol hosts (you can have different drives in a single robot
attached to multiple hosts). In our scenario it works great because we
a)use centralized duplication and b)have clusered robotics control hosts
so our chances of having a downed robot is very low.

Again, it all depends on what you are tring to do, what you
currently have and how much you are willing to spend.

paulg

Save On Jan 27, 8:33pm, Williams, Kristopher L wrote:
Subject: [Veritas-bu] Virtual Tape Library / Drives Hello all,


I'm trying to get my head around exactly what and how a virtual tape
drive system works.

Here is how I see it: VTL is mostly a software product that allows me
to
create virtual libraries and tape devices. I can then present those
devices to any host connected to the FC SAN. (I know that some offer
iSCSI but I only want to deal with Fiber in my example). Those virtual
tape drives get written to by NetBackup just like normal tape drives,
but the data really is stored on a central disk subsystem. Using NB
duplication, I can get the data off to real tapes to be vaulted for DR
purposes.

I guess the first idea that comes to mind is to place a virtual drive
on
every SAN attached host and make them all SAN media managers (I know
that Veritas License Cost will make this sound crazy). I could then
have
each SAN Media server write it's own data to it's local "Virtual" tape
drive.

Can someone who has a VTL system fill in the holes for me? I'm sure
there are many many more considerations but I'm just at the thinking
phase.


Thanks,

Kris

_______________________________________________
-- End of excerpt from Williams, Kristopher L

If you use the VTL to duplicate images to physical tape, NetBackup will have no idea that the image has been copied. Likewise, if you expire the VTL image and just have a physical tape copy left, in order to do a NetBackup restore you will first have to import the tape copy - either to the VTL, or into NetBackup, before you'll be able to proceed. Also, be aware that NetBackup does not currently support VTLs emulating anything - our EMC CDLs show up as "EMC CLARiiON DL DEV v1.0" for example, although they function as STK L700s. =)

See also http://seer.support.veritas.com/docs/264984.htm for the best practices doc.

John Nardello
T-Mobile: Enterprise Systems Backup Group Technical Lead
"Your backups are only as good as your restores."


-----Original Message-----
From: veritas-bu-admin < at > mailman.eng.auburn.edu
[mailto:veritas-bu-admin < at > mailman.eng.auburn.edu]
Sent: Thursday, January 27, 2005 8:36 PM
To: Paul Gimpelev; List Veritas List
Subject: RE: [Veritas-bu] Virtual Tape Library / Drives


Paul,

I read about what I think you mean by "out of the back end duplication".
If I have it right, with certain subsystems you can run FC from the disk
straight to the tape library. The VTL is smart enough to know how to
duplicate images to the tapes. I guess the only thing I don't understand
is where NetBackup comes into play with that piece. Does NetBackup
somehow control the duplication process even though the data isn't going
through a media server? What I would want to avoid is using some other
software program to managed the duplication from the VTL to live tape
library.

As for the separate connection to the VTL, in our Windows environment we
currently have two FC cards in each SAN attached box. We have two disk
SAN's and connect one card to each for failover (Securepath). Currently
we just allocate tape devices through these two cards. For Windows, we
do not have a separate SAN for just tape. I know this would probably be
the best bet, but with the limited number of PCI card slots in most
newer servers, using 3 for FC cards just isn't possible.

I thought of one more question. Has anyone used VTL with NT 4.0? I know
it's a dieing breed, but not everyone is up to Win2k just yet.

Thanks,

Kris

-----Original Message-----
From: Paul Gimpelev [mailto:paulg < at > CDCNA.COM]
Sent: Thursday, January 27, 2005 9:50 PM
To: Williams, Kristopher L; List Veritas List
Subject: Re: [Veritas-bu] Virtual Tape Library / Drives

Kris,

Your general understanding of how VTL works is pretty much
correct.
There are certain advantages to VTL which you have not mentioned such
as "out of the back end duplication" but if you need to keep an image
on-site as well as physical tape off site at the same time then you got
it. As far as whether to make any SAN attached host a media server
depends entirely on your configuration and what you need to back up off
of these hosts. If the amount of data is trivial, then it may be more
efficient to back them up over the network. You also need to consider
that VTL, just as a physical tape library, would require a separate SAN
connection(s) for the tape drive(s) apart from your existing SAN
connections to the disks.

Depending on your configuration, you might consider using fewer
robotics contorol hosts (you can have different drives in a single robot
attached to multiple hosts). In our scenario it works great because we
a)use centralized duplication and b)have clusered robotics control hosts
so our chances of having a downed robot is very low.

Again, it all depends on what you are tring to do, what you
currently have and how much you are willing to spend.

paulg

Save On Jan 27, 8:33pm, Williams, Kristopher L wrote:
Subject: [Veritas-bu] Virtual Tape Library / Drives Hello all,


I'm trying to get my head around exactly what and how a virtual tape
drive system works.

Here is how I see it: VTL is mostly a software product that allows me
to
create virtual libraries and tape devices. I can then present those
devices to any host connected to the FC SAN. (I know that some offer
iSCSI but I only want to deal with Fiber in my example). Those virtual
tape drives get written to by NetBackup just like normal tape drives,
but the data really is stored on a central disk subsystem. Using NB
duplication, I can get the data off to real tapes to be vaulted for DR
purposes.

I guess the first idea that comes to mind is to place a virtual drive
on
every SAN attached host and make them all SAN media managers (I know
that Veritas License Cost will make this sound crazy). I could then
have
each SAN Media server write it's own data to it's local "Virtual" tape
drive.

Can someone who has a VTL system fill in the holes for me? I'm sure
there are many many more considerations but I'm just at the thinking
phase.


Thanks,

Kris

_______________________________________________
-- End of excerpt from Williams, Kristopher L

Kris,

NetBackup does not know if VTL duplicates tapes out of the back. This
presents a problem - you can only have a single copy of the tape. Say NBU host
wrote to tape VLT000 on the virtual library and that tape got duplicated
through the back end to a physical LTO tape with label VTL000(has to be the
same) then once the duplication is done VTL will erase it's own tape copy and
only one on physical media will exist. If you need to retain two copies of the
tape, one on-site the other off-site at the same time you will need to use NBU
duplication through either Vault or manually.

Using same cards for disk and tape is definitely not recommended by any
vendor I know. You can, potentially, avoid the issue of limited PCI slots by
using dual-port HBAs.

As far as using NT 4.0 you will need to check with a specific VTL
vendor, they may or may not support it.

A good Virtual Tape system will completely offload the task of media
management from your hosts. It will store it's own policies which
allow you to specify things like "keep this logical volume on disk for
7 days, and write two copies to tape immediately, one of which will be
sent offsite for a year".

NetBackup doesn't need to know anything about it. Why would you get
NBU and a host to do the duplication when there's a purpose built
system there that can handle it all with no impact to hosts.

It *is* a seperate point of management, and in a DR you would need to
recover your Virtual Tape system before you started restoring systems.
People from a mainframe background have been working this way for
decades.

In a multiple SAN media server with SSO environment, I would prefer to
deal with one centralised point of media management, rather than
dozens of media servers and trying to get SSO working nicely.

Of course if you use multiple types of backup software (CA, Tivoli,
whatever) which a lot of companies still do, a good VTS will allow you
to share your infrastructure between them all.

That's my 2cents worth!

On Fri, 28 Jan 2005 17:27:34 -0500, Paul Gimpelev <paulg < at > cdcna.com> wrote:
Kris,

NetBackup does not know if VTL duplicates tapes out of the back. This
presents a problem - you can only have a single copy of the tape. Say NBU host
wrote to tape VLT000 on the virtual library and that tape got duplicated
through the back end to a physical LTO tape with label VTL000(has to be the
same) then once the duplication is done VTL will erase it's own tape copy and
only one on physical media will exist. If you need to retain two copies of the
tape, one on-site the other off-site at the same time you will need to use NBU
duplication through either Vault or manually.

Using same cards for disk and tape is definitely not recommended by any
vendor I know. You can, potentially, avoid the issue of limited PCI slots by
using dual-port HBAs.

As far as using NT 4.0 you will need to check with a specific VTL
vendor, they may or may not support it.
_______________________________________________

Theres also a good(not perfect write up on the VAN network)
http://www.veritas.com/Vrt/offer?_requestid=34252&a_id=9789&

Jim

-----Original Message-----
From: veritas-bu-admin < at > mailman.eng.auburn.edu
[mailto:veritas-bu-admin < at > mailman.eng.auburn.edu] On Behalf Of Nardello, John
Sent: Friday, January 28, 2005 10:42 AM
To: veritas-bu < at > mailman.eng.auburn.edu
Subject: RE: [Veritas-bu] Virtual Tape Library / Drives


If you use the VTL to duplicate images to physical tape, NetBackup will have
no idea that the image has been copied. Likewise, if you expire the VTL
image and just have a physical tape copy left, in order to do a NetBackup
restore you will first have to import the tape copy - either to the VTL, or
into NetBackup, before you'll be able to proceed. Also, be aware that
NetBackup does not currently support VTLs emulating anything - our EMC CDLs
show up as "EMC CLARiiON DL DEV v1.0" for example, although they function as
STK L700s. =)

See also http://seer.support.veritas.com/docs/264984.htm for the best
practices doc.

John Nardello
T-Mobile: Enterprise Systems Backup Group Technical Lead
"Your backups are only as good as your restores."


-----Original Message-----
From: veritas-bu-admin < at > mailman.eng.auburn.edu
[mailto:veritas-bu-admin < at > mailman.eng.auburn.edu]
Sent: Thursday, January 27, 2005 8:36 PM
To: Paul Gimpelev; List Veritas List
Subject: RE: [Veritas-bu] Virtual Tape Library / Drives


Paul,

I read about what I think you mean by "out of the back end duplication". If
I have it right, with certain subsystems you can run FC from the disk
straight to the tape library. The VTL is smart enough to know how to
duplicate images to the tapes. I guess the only thing I don't understand is
where NetBackup comes into play with that piece. Does NetBackup somehow
control the duplication process even though the data isn't going through a
media server? What I would want to avoid is using some other software
program to managed the duplication from the VTL to live tape library.

As for the separate connection to the VTL, in our Windows environment we
currently have two FC cards in each SAN attached box. We have two disk SAN's
and connect one card to each for failover (Securepath). Currently we just
allocate tape devices through these two cards. For Windows, we do not have a
separate SAN for just tape. I know this would probably be the best bet, but
with the limited number of PCI card slots in most newer servers, using 3 for
FC cards just isn't possible.

I thought of one more question. Has anyone used VTL with NT 4.0? I know it's
a dieing breed, but not everyone is up to Win2k just yet.

Thanks,

Kris

-----Original Message-----
From: Paul Gimpelev [mailto:paulg < at > CDCNA.COM]
Sent: Thursday, January 27, 2005 9:50 PM
To: Williams, Kristopher L; List Veritas List
Subject: Re: [Veritas-bu] Virtual Tape Library / Drives

Kris,

Your general understanding of how VTL works is pretty much correct.
There are certain advantages to VTL which you have not mentioned such as
"out of the back end duplication" but if you need to keep an image on-site
as well as physical tape off site at the same time then you got it. As far
as whether to make any SAN attached host a media server depends entirely on
your configuration and what you need to back up off of these hosts. If the
amount of data is trivial, then it may be more efficient to back them up
over the network. You also need to consider that VTL, just as a physical
tape library, would require a separate SAN
connection(s) for the tape drive(s) apart from your existing SAN connections
to the disks.

Depending on your configuration, you might consider using fewer
robotics contorol hosts (you can have different drives in a single robot
attached to multiple hosts). In our scenario it works great because we
a)use centralized duplication and b)have clusered robotics control hosts so
our chances of having a downed robot is very low.

Again, it all depends on what you are tring to do, what you
currently have and how much you are willing to spend.

paulg

Save On Jan 27, 8:33pm, Williams, Kristopher L wrote:
Subject: [Veritas-bu] Virtual Tape Library / Drives Hello all,


I'm trying to get my head around exactly what and how a virtual tape
drive system works.

Here is how I see it: VTL is mostly a software product that allows me
to
create virtual libraries and tape devices. I can then present those
devices to any host connected to the FC SAN. (I know that some offer
iSCSI but I only want to deal with Fiber in my example). Those virtual
tape drives get written to by NetBackup just like normal tape drives,
but the data really is stored on a central disk subsystem. Using NB
duplication, I can get the data off to real tapes to be vaulted for DR
purposes.

I guess the first idea that comes to mind is to place a virtual drive
on
every SAN attached host and make them all SAN media managers (I know
that Veritas License Cost will make this sound crazy). I could then
have
each SAN Media server write it's own data to it's local "Virtual" tape
drive.

Can someone who has a VTL system fill in the holes for me? I'm sure
there are many many more considerations but I'm just at the thinking
phase.


Thanks,

Kris

_______________________________________________
-- End of excerpt from Williams, Kristopher L