Hope i'm posting this in the right place... I've worked with NetApp filers for years including the re-badged versions such as the one in question but last week the total capacity / usable capacity dropped from 52TB to 52 which confused me as i've never seen the total capacity drop. I've not had a chance to go through all the logs yet but wondering if anyone has any instant ideas.
It's a fabric metro cluster, only 1 data aggregate which was recently running very low on space (down to the last 4-5TB) we planned to remove 4 of the 7 nightly snapshots to free up space until the new disk shelves were in place next year. This as performed last Monday and within 2 days we had about 11TB free again from the 4.5TB. After a few days the capacity dropped and the snapshot space in the aggregate continued to grow til it was almost full but it appears it has settled back down now to around 60% usage. We run asis too and snapmirorrs are running frequently to a 3rd site DR. I believed that the capacity available drop was because the data agar was about to spill into the agar data space but since it's gone back down now, this makes no sense.
From my putty logs before the work commenced i'm now sure the issue is exactly as i said, the aggr SR pushed very close to the 5% and now i can see that the Snap reserve on that aggregate has changed from 5% as standard to 7%... hence the 900GB of data less available on the capacity.
So unless anyone has other ideas i'm happy with my findings and will reset the SR on the aggregate when the snaps settle.