Best way to create tape?

[Tim Medford]

One of our database cold backup scripts uses fbackup and writes to a disk device. The command looks something like this:

fbackup -I /tmp/bkupindex -f /backup_fs/backupfile -0u -y -g /tmp/mygraph

This works great and it's pretty fast too. My question is about how to get this backup file written to tape for offsite storage?

If possible, I would like the tape to be written in the same format as if fbackup had actually written directly to the the tape originally? So then later if I had to use the tape, I could simply:

frecover -x -o -v -i /ora_work3 -f /dev/rmt/c4t6d0BEST

Does anyone know if this is possible? I was hoping that I wouldn't have to first restore /backup_fs/backupfile and then run frecover against it.

Thanks in advance!
Tim

[Rodney Hills · Accepted solution]

fbackup writes the data differently to tape drives than to disk (ie fast search marks).

Though "tar" files can be copied to tape using the "dd" command, this option is not available with fbackup.

You will have to fbackup to tape your disk file and just be sure you have room on your disk to restore the disk file fbackup that you put on tape.

-- Rod Hills

[A. Clay Stephenson]

Hi Tim:

The good news is that you have chosen the best (fastest, most efficient) of the free backups available on HP-UX; the bad news is that the media can't be copied - at least tape to tape. You would have to restore and then backup again. You could use tar or cpio but they won't be nearly as fast for your backups.

If this is a critical application (and I assume that it is); I suggest that you take the plunge and invest in a real backup product like OmniBack. You can completely automate your backups and the copies for offsite storage.

[James R. Ferguson]

Hi Tim:

Perhaps I'm missing something. Why not just create the proprietary 'fbackup' tape, instead of the disk file, and then use 'frecover's '-I' and/or 'N' options to create a listing of the tape's contents? You don't need to actually recover anything to obtain a listing of the files on your tape and you can edit the generated output to form new graph files for an actual 'frecover'. See the man pages for 'frecover' for more information.

Regards!

...JRF...

[Tim Medford]

James - What I'm doing is just a cold backup of a couple oracle databases.

The reason I write to disk is for speed (need to have the db back up asap!) and also I like having the backup file onsite in case I need to use it.

The tape is a fallback strategy in case we lost the whole building to disaster or something.

Once the disk backup is complete the database comes back up and I can take my sweet time creating a tape while the rest of the world is using the database again.

Tim

[Rodney Hills]

If having your DB available is critical, then look into disk mirroring. I have a short window where I split the mirrors and backup the unchanging file system and let the users update the production system. When the tape backup is done, I do a lvm merge and the mirrors are placed back in sync.

-- Rod Hills

[A. Clay Stephenson]

Here's a Plan B and you don't take the huge I/O hit of vgsyncs. Using OnlineJFS, shutdown the database, make vxfs snapof= mounts of your Oracle data, then restart the database (about 2 minutes). You then backup using the snapshot mounts. This gives you the warm-fuzzy of a cold backup with almost no downtime. You could actually then make two backups from the snapshots, if you like.