2014-10-15 02:36 AM
We have a highly active volume and our nightly snapshots can thus grow rather large.
Therefore we limited the snaphots to 2 nightly (snap sched VolX 0 2 0)
There is a major drawback with this because I cannot restrict certain weekdays.
I would call it a flaw in design by netapp.
The thing is that on weekends and holidays there is almost no activity and after an extended weekend the valuable snapshots have been replaced by rather useless small snapshots.
As a workaround I could use cron triggered snapshots from some helper machine e.g. ssh roo@myFiler "snap create VolName SnapName" but then I need another script around it which takes care of deleting and renumbering snapshots.
Although this gives full control I would rather have the filer handle all the stuff.
Does anybody know if the problem can be solved on the filer only?
2014-10-16 08:58 AM
Not sure about controlling from the filer.
However if it is for Cluster mode you can look at the workflows posted here which can help you.
2014-10-20 05:06 AM - edited 2014-10-20 05:08 AM
From digging around more I think finer scheduling is not possible directly through the filer.
I also found that the manual tells something wrong about snapshots exception on sunday.
"man snap" says "Daily snapshots are created at 24:00 of each day except Sunday, and weekly snapshots are created at 24:00 on Sunday."
I have configured 4 daily snapshots no weekly and no hourly ( = snap sched 0 4 0) and I very well see a snapshot from 24:00 at sunday.
This is even more awkward as it means that during an inactive weekend 2 valuable snapshots from weekdays are scrapped in favour of almost nothing.
My guess is that the manual wants to point out that if weekly snapshots are defined these will replace the nightly snapshot on sundays.
Thus if weekly AND nightly snapshots are configured there will be no nightly snapshot on sunday.
So I deciced to make my own snapshot scheduling.
I added a public key to vol0/etc/sshd/root/.ssh/authorized_keys and will use a script which I schedule from a linux server using cron.
This way I have full control over snapshot scheduling and the flexibility I want.
The sacrifice is that snapshotting now depends on an external host