backups = 100% cpu

i'm having weird problems with a server.
backups to disk are causing the cpu to get pegged at 100% usage.
the backups are much slower than they used to be.
my theory is it's either glitchy network or glitchy SAN.
if sql server is having problems reading or writing to disk (like
happens during backups), would that be the cause of 100% cpu?
i traced the server using profiler, but saw nothing out of the ordinary
as far as cpu usage when the backups were running, but task manager
definitely shows that sqlserver is using the cpu.
on a test db of 200mb, a trasaction log backup takes 7 seconds to create
a 30kb backup file and then another 7 seconds to veryify that 30kb
backup file. i load that same test db on another server and it's 1
second to backup and 1 to verify without the massive cpu usage.ch wrote:
> i'm having weird problems with a server.
> backups to disk are causing the cpu to get pegged at 100% usage.
> the backups are much slower than they used to be.
> my theory is it's either glitchy network or glitchy SAN.
> if sql server is having problems reading or writing to disk (like
> happens during backups), would that be the cause of 100% cpu?
> i traced the server using profiler, but saw nothing out of the
> ordinary as far as cpu usage when the backups were running, but task
> manager definitely shows that sqlserver is using the cpu.
> on a test db of 200mb, a trasaction log backup takes 7 seconds to
> create a 30kb backup file and then another 7 seconds to veryify that
> 30kb backup file. i load that same test db on another server and
> it's 1 second to backup and 1 to verify without the massive cpu usage.
Where are you writing the backups? Some details about your configuration
would help here.
--
David Gugick
Imceda Software
www.imceda.com|||"ch" <ch@.dontemailme.com> wrote in message
news:41E6BA88.602612AB@.dontemailme.com...
> i'm having weird problems with a server.
> backups to disk are causing the cpu to get pegged at 100% usage.
> the backups are much slower than they used to be.
> my theory is it's either glitchy network or glitchy SAN.
> if sql server is having problems reading or writing to disk (like
> happens during backups), would that be the cause of 100% cpu?
> i traced the server using profiler, but saw nothing out of the ordinary
> as far as cpu usage when the backups were running, but task manager
> definitely shows that sqlserver is using the cpu.
How are you attached to the SAN? Is it FC or iSCSI?
> on a test db of 200mb, a trasaction log backup takes 7 seconds to create
> a 30kb backup file and then another 7 seconds to veryify that 30kb
> backup file. i load that same test db on another server and it's 1
> second to backup and 1 to verify without the massive cpu usage.