I have a question. A month or so back
we had massive performance problems on our
3170A and disks were 100% for no apparent reason
(SATA drives).
Netapp eventually tracked down the problem to
snapshot deletion. It seems that blocks are zeroed
as they are returned to the aggregate.
It was taking longer than 60 mins to
delete the hourly snapshots.
So, my questions are:
1) has anybody else seen this problem and been forced
to avoid hourly snaps?
2) is there any way to disable the zeroing of
freed blocks?
3) has anybody heard of a plan for a fix which would allow
us to use hourly snaps again?
It seems bizarre that a useful feature, which we have
used for a long time, has become unusable.
Basically, it appears I/O is doubled becuase the blocks are
written when used, then written when freed.
Regards,
pdg