Hi there,

about two weeks ago there was a small thread on mirroring your database
volumes.
Why? To protect you from diskcrashes and from logical failures due to
corrupt pages.
Our biggest concern was the performance impact.
Some off the list members claimed that the impact was minimal. The gain in
reliability was worth it. So we went for it.

After applying database volume mirrors, the impact in the daily operations
was minimal indeed.
We configured :
    This is a DB of 36GB assigned capacity. (disks spread on ESS over two
FC's)
    mirrorwrite db sequential
    mirrorread db normal

    mirrorwrite log parallel
    mirrorread log normal

BUT, when performing a database backup using "backup db type=full dev=3590"
the duration went from 40 minutes to 300 minutes.
Backing up the DB to disk showed the same results.
I'd say this is a decrease of performance. In the 3 hours the database
backup takes, many changes have been made to the DB and i'd rather not rely
on this backup.

Does any of you have the same experience?



Ilja G. Coolen



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ABP / USZO
CIS / BS / TB / Storage Management
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