Backup of DB2 on Windows 2003 using open file option

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Charles Morrall - 27 Jan 2005 21:52 GMT

I have no experience with DB2 as such, but I've been tasked with configuring
backup of a server running DB2 v8 on Windows Server 2003. I do have some
experience with backups in general though. The backup software I'll be using
is Backup Exec 10, but Backup Exec doesn't have a specific agent for DB2, as
it does for SQL and Oracle. The supplier of Backup Exec claims I can use the
Open File option of Backup Exec to backup DB2.
I find this a bit strange, I would have thought reading locked database
files and backing up was a bad thing to do, because I of course have to
guarantee I can restore the database to a consistent state in case of crash.
I've posted a similar question of Veritas' support forum, and the reply was
essentially "we can't guarantee it will work with open file".
Of course I can shut down DB2 and do a cold backup, or use the dump feature
( I assume DB2 has a dump feature) but I'm specifically looking for on-line
backups.
/charles

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Mark A - 27 Jan 2005 22:00 GMT

> I have no experience with DB2 as such, but I've been tasked with configuring
> backup of a server running DB2 v8 on Windows Server 2003. I do have some
[quoted text clipped - 11 lines]
> backups.
> /charles

DB2 has on-line backups. But you will need the log files that are active
during the backup if you want to restore an on-line backup. However, if you
have DB2 8.2 (free upgrade from 8.1 just by applying the latest fixpak) then
there is an option in the on-line backup to also include the necessary log
files in the backup image. See the Command Reference manual.

You cannot backup DB2 just by backing up the file systems (I should say you
cannot successfully restore DB2), unless you backup/restore the entire disk
drive (all drives that DB2 is using) while DB2 is off-line.

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Charles Morrall - 27 Jan 2005 22:06 GMT

>> Of course I can shut down DB2 and do a cold backup, or use the dump
> feature
[quoted text clipped - 16 lines]
> disk
> drive (all drives that DB2 is using) while DB2 is off-line.

By "DB2 has on-line backups" do you mean I can export an on-line database
(dump) while the database is running, and in the next stage use my backup
application to backup the export to tape (or disk in my case)?
/charles

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Mark A - 27 Jan 2005 22:14 GMT

> By "DB2 has on-line backups" do you mean I can export an on-line database
> (dump) while the database is running, and in the next stage use my backup
> application to backup the export to tape (or disk in my case)?
> /charles

Yes, you can backup while DB2 is running and people are updating the data.
However it is best to do the backup at time when the least amount of updates
are being done, because this will reduce the number of logs that need to be
saved with the backup, and reduce the restore time (if a restore is needed).

After the backup is taken, you could copy the file to tape, and reverse the
process for the restore. Products like TSM (Tivoli Storage Manager) that
have a DB2 interface will do this automatically for you without the 2 step
process and also backup your other file systems..

Just remember to also backup the logs that are active during the backup, or
use 8.2 and indicate that you want the needed logs in the backup image.

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Mark A - 27 Jan 2005 22:18 GMT

> Yes, you can backup while DB2 is running and people are updating the data.
> However it is best to do the backup at time when the least amount of updates
[quoted text clipped - 8 lines]
> Just remember to also backup the logs that are active during the backup, or
> use 8.2 and indicate that you want the needed logs in the backup image.

One thing to add, you must enable "log retain" (or specify an archive exit
program) in the DB CONFIG in order to do an on-line backup. The default is
circular logging when you create a database.

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Stanley Sinclair - 27 Jan 2005 23:41 GMT

I haven't seen the Veritas product for a few years, but I think the
intent was to make a quick image (or copy ?) of the open file
elsewhere, and then include that in the backup instead of the actual
open file. The logs should then allow consistent restore.

However, DB2 version 8.2 has its own great backup utility (including
compression) which might obviate the situation, although I don't know
about on-line -- comment from the experts? Both the Vertas (Backup
Exec) and the CA (Arcserve & Brightstor) products have open file
capabilities (not even options any more), so I assume that they work
somehow.
Don't expect anyone to say that "We guarantee it will work ..."

Stan

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Mark A - 28 Jan 2005 00:00 GMT

> I haven't seen the Veritas product for a few years, but I think the
> intent was to make a quick image (or copy ?) of the open file
[quoted text clipped - 10 lines]
>
> Stan

The experts have already commented.

Backing up operating system files will not suffice for a backup of DB2 while
it is running. Even off-line, a file system backup would have to include all
disks on the system that DB2 touched.

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