topic Error message when using tar for online backup in Operating System - HP-UX

Error message when using tar for online backup

Simon Qu — Wed, 01 Oct 2003 11:13:48 GMT

I have a script to run online backup for our oracle8i databse on hp-ux 11i. The script looks like:
.
.
if (tar -cvhf /dev/rmt/0m `cat datafiles.lst`)
then
echo "Database successfully backed up!!!" >> online_backup.log
else
echo "Database backup failed." >> online_backup.log
fi

tar -tvf /dev/rmt/0m >> online_backup.log

When I check the log file, I see all datafiles on the list. It seems to me all files are backuped fine, but I also see the "Database backup failed" in the log file. Why?

I appreciate any responses.

Thanks.

Re: Error message when using tar for online backup

Mark Grant — Wed, 01 Oct 2003 11:26:29 GMT

There isn't anything I can see wrong with this but in this script, the file is always appended to, are you quite sure you're not just seeing previous failed runs?

Why do you have brackets around your first tar command?

Re: Error message when using tar for online backup

Patrick Wallek — Wed, 01 Oct 2003 11:35:13 GMT

My guess would be that your backup is erroring out somewhere. Do you see any errors anywhere? Are you sure it is not needing a 2nd tape?

I would consider trying something like:

tar -cvhf /dev/rmt/0m $(cat datafiles.lst) > backup.log 2>&1
if [ $? = 0 ]
then
echo "Database successfully backup up!"
else
echo "It wasn't"
fi

The tar statement will still do your backup, but it will send all of its output, both standard out and standard error, to the backup.log file so you can see if you are getting any errors.

Re: Error message when using tar for online backup

Sundar_7 — Wed, 01 Oct 2003 11:36:19 GMT

Would that be a better idea to check only the return value of tar ?

tar -cvhf /dev/rmt/0m `cat datafiles.lst` 1>/tmp/out 2>&1

if [[ $? -ne 0 ]]
then
echo "Database backup failed." >> online_backup.log
else
echo "Database successfully backed up!!!" >> online_backup.log
fi

Re: Error message when using tar for online backup

Vitek Pepas — Wed, 01 Oct 2003 11:49:00 GMT

Man page for tar does not mention returned values, so I don't think you can rely on them in 'if' statement.

Re: Error message when using tar for online backup

Vitek Pepas — Wed, 01 Oct 2003 12:04:04 GMT

Actually, I'm sure you can't rely on the value returned by tar. I had the same problem some time ago. I was running HP-UX 10.20 then, but it may be the same in 11.x.
I solved the problem by switching to fbackup.

Re: Error message when using tar for online backup

Simon Qu — Wed, 01 Oct 2003 12:07:30 GMT

Thank you all.
I used the same script on hp-ux10.20 and it worked fine. Now we just moved to hp-ux11i. Does the "tar" have something specail on 11i ?

Re: Error message when using tar for online backup

GK_5 — Wed, 01 Oct 2003 13:27:44 GMT

Try just running command tar -cvhf /dev/rmt/0m $(cat datafiles.lst) > backup.log 2>&1
And see if it works. Tar does return code 0 for successful command on 11i as well.

-GK-

Re: Error message when using tar for online backup

Simon Qu — Wed, 01 Oct 2003 16:31:10 GMT

I got an error like this:
tar: Size of /db01/oracle/vis_sales_01.dbf > 2GB. Not dumped.

This datafile is greater than 2GB. Is there a way to backup this much big file?

Thanks.

Re: Error message when using tar for online backup

Chris Vail — Wed, 01 Oct 2003 16:40:16 GMT

If your data file is larger than 2 GB, the HPUX's standard tar command will barf and die. You can use the gnu version of tar and go up to 4GB (it may be 8GB now). You can't use the default version of gzip either, for the same reason. You can get a better version of either command from www.gnu.org.

Chris

Re: Error message when using tar for online backup

Patrick Wallek — Wed, 01 Oct 2003 16:47:34 GMT

Ahhh...Now we get to the real problem.

The native HP-UX tar can *NOT* handle large files (ie. larger than 2GB). There is a patch available for HP-UX 11i that will allow it to archive files up to 8GB.

NOTE -- If you install this patch then your tar archive will *ONLY* work on other HP-UX machines with this patch applied.

The patch you need to get this to work is PHCO_28992.
http://www1.itrc.hp.com/service/patch/patchDetail.do?patchid=PHCO_28992&context=hpux:800:11:11

Re: Error message when using tar for online backup

Simon Qu — Thu, 02 Oct 2003 14:47:02 GMT

Thank all you guys.
I installed the patch Partick recommended. It worked fine.

Re: Error message when using tar for online backup

Alzhy — Thu, 02 Oct 2003 15:17:00 GMT

Simon,

Someday you will encounter files greater than 8GB.. I suggest you start using GNU tar which addresses some of the limitations of most Unix's bundled tar... Did you know that even Veritas uses it (GnuTar) in its NetBackup product?