Veritas-bu

[Veritas-bu] inconsistent (?) catalog backups

2001-11-16 09:50:16
Subject: [Veritas-bu] inconsistent (?) catalog backups
From: Max.Booth AT ubsw DOT com (Max.Booth AT ubsw DOT com)
Date: Fri, 16 Nov 2001 14:50:16 +0000
David,

By calling the script to perform the snapshots from within
session_notify the image database will be in a quiescent
state.  The process is as follows:

Last active job completes.
- Cleaning image DB
- Deleting Expired Images
- cleaning media DB(s)
- runing session_notify
- performing database backup

The performing database backup is when it attempts to
run the internal bpbackupdb if set.

I believe that there might be an instance, where you are
running duplication jobs, and a sheduled backup comes
in, completes and thus calls a session_notify whilst
duplication is still running (and accessing the image DB).
In this case, it is possible that a file may be in the
process of updating when the snapshot is taken.
I suppose the same could be true for User Backups but
not 100% sure on this one.

File system snapshots take a matter of seconds to complete
even on large volumes of around 100Gb so the likelihood
of this occuring is very small.

In addition, you could also set the backup script to
check for duplication (or ubak) processes prior to running
the snapshots.

Regards,

max

-----Original Message-----
From: david 
Sent: 16 November 2001 14:28
To: Booth, Max; kesich
Cc: david; veritas-bu
Subject: RE: [Veritas-bu] inconsistent (?) catalog backups


What if the NBU catalog is being updated during the time of the 
snapshot?
Are you still opening yourself up to an inconsistent catalog backup?

David

<><><><><><><><><><><><><><><><><><><><>
David A. Chapa
NetBackup Consultant
DataStaff, Inc.
http://www.consulting.datastaff.com
847 413 1144
---------------------------------------
NBU-LSERV AT datastaff DOT com - Adv. Scripting
http://www.xbpadm-commands.com

-----Original Message-----
From: veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]On Behalf Of
Max.Booth AT ubsw DOT com
Sent: Friday, November 16, 2001 2:30 AM
To: kesich AT nyu DOT edu
Cc: veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] inconsistent (?) catalog backups


You could do this using vxfs snapshots, the benefit this
has is that you can still keep your environment running
the entire time which, given the time it can take to backup
a catalogue, can be very important.

Basically you need a script which calls a snapshot of the
database partition, then runs your 2 stage backup in the
background.

If you call this script from within session_notify, which is
called when the last active backup finishes, you know that
there is no other activity going on so you have a consistent
point in time view of your database.

You would also want to put some locking into the script,
and a check to ensure that it only runs once every 24 hours,
to prevent it from doing a database backup after every session
end.

Regards,

max

-----Original Message-----
From: david
Sent: 15 November 2001 15:47
To: kesich; veritas-bu
Cc: david
Subject: RE: [Veritas-bu] inconsistent (?) catalog backups


What I do to ensure I get a good backup for my client's DR is the
following

ps -ef | grep bprd | grep -v grep
if [ $? = 0 ]; then
/usr/openv/netbackup/bin/admincmd/bprdreq -terminate
if [ $? != 0 ];then
echo "CANNOT TERMINATE BPRD, THE CATALOG BACKUP MAY BE QUESTIONABLE
IF WE
CONTINUE" >> LOGFILE
exit 1
else
echo "Successfully terminated bprd. No backup jobs will run during
the DB
backup" >> LOGFILE
fi
fi
/usr/openv/netbackup/bin/admincmd/bpdbjobs -M $MASTER_SERVER -report |
egrep -i "Active" > /dev/null
#
#       Set variable NOJOBS to the return code of previous line
#       if it returned a zero (0), then the condition of the
#       until loop is met.  If not, we stay in the until
#       loop until it is met, sleeping for 10 minutes each
#       time the condition is not met
#
#
#
NOJOBS=$?
until [ $NOJOBS -ne 0 ]
        do
         sleep 600
         $ADMCMD/bpdbjobs -M $MASTER_SERVER report | egrep -i "Active"
>/dev/null
         NOJOBS=$?
        done
# Backup Databases here
        echo "Backing up NBU Databases"
bpbackupdb -blah -blah -blah

# then after its done
# Re-starting the Request Daemon
/usr/openv/netbackup/bin/initbprd
if [ $? = 0 ];then
echo "Successfully started bprd. All backup jobs will run when
scheduled" >>
$LOGFILE
else
echo "The request daemon, bprd, failed to start.  No backup jobs will
run"
>> $LOGFILE
fi


That should do it for you.

I would think snapping it would have the same inherent problems.  If
you
stopped bprd as above and waited for all jobs to complete, snapped
it, then
restarted bprd you'd be safe.

David

<><><><><><><><><><><><><><><><><><><><>
David A. Chapa
NetBackup Consultant
DataStaff, Inc.
http://www.consulting.datastaff.com
847 413 1144
---------------------------------------
NBU-LSERV AT datastaff DOT com - Adv. Scripting
http://www.xbpadm-commands.com

-----Original Message-----
From: veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]On Behalf Of John
Kesich
Sent: Wednesday, November 14, 2001 11:37 AM
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] inconsistent (?) catalog backups


I need clarification of what is meant by an "inconsistent catalog
backup" on
p. 161 of the NBDC System Administrator's Guide.

If any of the forbidden operations would render the catalog backup
useless
for disaster recovery the suggested procedure is worthless without an
interlock mechanism.

If such a procedure is used by the automatic catalog backups why
hasn't
it been used in the script provided?

How can one be sure that both the images backup and catalog backup are
"consistent"?

Finally, if the catalog is on a VxFS filesystem, would snap'ing it
avoid
the consistancy issue?
_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu

_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu



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