Gionatan Danti schreef op 14-04-2017 9:23:
Il 13-04-2017 14:59 Stuart Gathman ha scritto:
Using a classic snapshot for backup does not normally involve
activating
a large CoW. I generally create a smallish snapshot (a few gigs),
that
will not fill up during the backup process. If for some reason, a
snapshot were to fill up before backup completion, reads from the
snapshot get I/O errors (I've tested this), which alarms and aborts
the
backup. Yes, keeping a snapshot around and activating it at boot can
be
a problem as the CoW gets large.
If you are going to keep snapshots around indefinitely, the thinpools
are probably the way to go. (What happens when you fill up those?
Hopefully it "freezes" the pool rather than losing everything.)
Hi, no need to keep snapshot around. If so, the classic LVM solution
would be completely inadequate.
I simply worry that, with many virtual machines, even the temporary
backup snapshot can fill up and cause some problem. When the snapshot
fills, apart from it being dropped, there is anything I need to be
worried about?
A thin snapshot won't be dropped. It is allocated with the same size as
the origin volume and hence can never fill up.
Only the pool itself can fill up but unless you have some monitoring
software in place that can intervene in case of anomaly and kill the
snapshot, your system will or may simply freeze and not drop anything.
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