Impact of transaction log backups in synchronous DB Mirroring syst

Hello,
We have a site on SQL Server 2005 SP2 EE. They are using synchronous
database mirroring. Both the principal and mirror are on a fast LAN. When
they perform transaction log backups on the principal database, our
application that accesses the principal database freezes for 1 or 2 seconds.
The transaction log backups are being written to the same disk where the
database resides. They have tried reducing the frequency of the transaciton
log backups to every 10 minutes, and that reduced the length of the app
freeze, but did not eliminate it. Has anyone heard of a problem running
transaction log backups when the database is mirrored?
Thanks,
HeatherI would be more concerned as to the placement of the log backups. Why would
you write them to the same disk that hold the data files? This is definitely
a candidate for a performance hit not to mention a problem if the disk
itself crashes. You loose both the data and logs and are probably in line to
update the resume. If you saturate the I/O the db can appear to freeze.
Andrew J. Kelly SQL MVP
Solid Quality Mentors
"HeatherK" <HeatherK@.community.nospam> wrote in message
news:E6A9E23D-916B-4CEE-8C3F-8801CD3394EB@.microsoft.com...
> Hello,
> We have a site on SQL Server 2005 SP2 EE. They are using synchronous
> database mirroring. Both the principal and mirror are on a fast LAN. When
> they perform transaction log backups on the principal database, our
> application that accesses the principal database freezes for 1 or 2
> seconds.
> The transaction log backups are being written to the same disk where the
> database resides. They have tried reducing the frequency of the
> transaciton
> log backups to every 10 minutes, and that reduced the length of the app
> freeze, but did not eliminate it. Has anyone heard of a problem running
> transaction log backups when the database is mirrored?
> Thanks,
> Heather