Backup slowing down systemcan it run at lower priority?

We have 200 databases (totalling about 20GB), and counting. I use
maintenance plans for backup--seems very convenient, and I don't have to
change anything when we add another DB.
Every night we do disk-to-disk backup at 9:30 (which runs screamingly
fast--only 10 minutes--because we backup to another disk), and then a
separate disk-to-tape backup occurs.
The problem: With the increased workload leading up to Christmas, the users
are saying the system slows down too much during those 10 minutes. They are
trying to use the system during live phone calls, and the caller can get
impatient--so they end up writing things on paper, which has to be entered
into the DB later. (Lots of extra work because somebody else has to replay
the tape of the call to do this.)
My main question is: Is there a way I can tell the backup to run at a lower
CPU priority?
I don't think we can backup directly to tape (thus reducing the load),
because other backup software needs to use the same tape after the SQL
backup is done. I suppose I could backup to the SAME disk, which would
almost certainly get rid of the CPU contention, but then there would be disk
contention instead, which may not be any improvement (it could even be
worse). And I'd rather not move away from using the maintenance plans
because of all the automatic stuff they do for me, like logging, deletion of
old files on my desired schedule, etc. Moving the backup later into the
night is problematic because (1) other backups need to happen afterward, and
some of them run most of the night--and sometimes the verify phase continues
well into the next day; and (2) nightly maintenance jobs and DB loads also
run later in the night.I presume this backup that is causing slowdown is a FULL backup ?
Can you do it out of hours?
Do you use LOG backups or DIFFERENTIAL backups?
Allan Mitchell (Microsoft SQL Server MVP)
MCSE,MCDBA
www.SQLDTS.com
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"Warren Odom" <no_spam@.no_spam.com> wrote in message
news:uvP%23vlOwDHA.3436@.tk2msftngp13.phx.gbl...
> We have 200 databases (totalling about 20GB), and counting. I use
> maintenance plans for backup--seems very convenient, and I don't have to
> change anything when we add another DB.
> Every night we do disk-to-disk backup at 9:30 (which runs screamingly
> fast--only 10 minutes--because we backup to another disk), and then a
> separate disk-to-tape backup occurs.
> The problem: With the increased workload leading up to Christmas, the
users
> are saying the system slows down too much during those 10 minutes. They
are
> trying to use the system during live phone calls, and the caller can get
> impatient--so they end up writing things on paper, which has to be entered
> into the DB later. (Lots of extra work because somebody else has to replay
> the tape of the call to do this.)
> My main question is: Is there a way I can tell the backup to run at a
lower
> CPU priority?
> I don't think we can backup directly to tape (thus reducing the load),
> because other backup software needs to use the same tape after the SQL
> backup is done. I suppose I could backup to the SAME disk, which would
> almost certainly get rid of the CPU contention, but then there would be
disk
> contention instead, which may not be any improvement (it could even be
> worse). And I'd rather not move away from using the maintenance plans
> because of all the automatic stuff they do for me, like logging, deletion
of
> old files on my desired schedule, etc. Moving the backup later into the
> night is problematic because (1) other backups need to happen afterward,
and
> some of them run most of the night--and sometimes the verify phase
continues
> well into the next day; and (2) nightly maintenance jobs and DB loads also
> run later in the night.
>
>|||"Allan Mitchell" <allan@.no-spam.sqldts.com> wrote in message
news:eim467OwDHA.2000@.TK2MSFTNGP11.phx.gbl...
> I presume this backup that is causing slowdown is a FULL backup ?
> Can you do it out of hours?
> Do you use LOG backups or DIFFERENTIAL backups?
Yes it's a full backup. We do log backups every half hour throughout the
day.
And my original post gave a lot of details why it would be a problem to
schedule the backup any later in the evening. (Although I did neglect to
mention this server is used 24/7.)
So can it be run at a lower priority or not?
-- Warren|||Backup isn't so much CPU intensive as it is disk I/O. So
if you're doing your disk backups to disks on the same
disk plane, you will see I/O issues, which affect SQL
Server. If you're backing up all 200 at once, you may
want to stagger them a bit ... that would certainly cause
contention.
Backing up to the same disk would be worse for I/O.
How are your disks set up?|||You have been offered some good suggestions already, I only want to answer
your concrete question:
> So can it be run at a lower priority or not?
No.
--
Tibor Karaszi, SQL Server MVP
Archive at:
http://groups.google.com/groups?oi=djq&as_ugroup=microsoft.public.sqlserver
"Warren Odom" <no_spam@.no_spam.com> wrote in message
news:uQfcAbPwDHA.3196@.TK2MSFTNGP11.phx.gbl...
> "Allan Mitchell" <allan@.no-spam.sqldts.com> wrote in message
> news:eim467OwDHA.2000@.TK2MSFTNGP11.phx.gbl...
> > I presume this backup that is causing slowdown is a FULL backup ?
> > Can you do it out of hours?
> > Do you use LOG backups or DIFFERENTIAL backups?
> Yes it's a full backup. We do log backups every half hour throughout the
> day.
> And my original post gave a lot of details why it would be a problem to
> schedule the backup any later in the evening. (Although I did neglect to
> mention this server is used 24/7.)
> So can it be run at a lower priority or not?
> -- Warren
>