On 09/14/2015 12:47 PM, Zdenek Kabelac wrote:
Dne 14.9.2015 v 20:05 Chris Friesen napsal(a):
Hi,
I'm running a 3.10 kernel with LVM 2.02.95.
I'm running into a problem where activating snapshots can take quite a long
time, roughly one minute per 25GB of delta between the snapshot and the origin
volume. (See below for my test procedure.)
I realize that my kernel/LVM aren't exactly bleeding edge, and I wondering
whether more recent versions have done anything to speed up the activation
process (like maybe making it more lazy-loaded rather than reading in a bunch
of data up-front).
If anyone is aware of such improvements, I'd appreciate it if you could point
me at the appropriate changes.
Hi
There is NO way to accelerate your existing setup, other then placing delta on
SSD - the format of snapshot was meant to be used 'temporarily' - i.e. until you
take backup of LV - but not for long-term multi-gigabyte case.
This is major mis-use of this 'snapshot' feature - which repeats over and over...
If you want to use long-living snapshots - you need to use thin-provisioning,
Thanks for the quick response.
Presumably we would still have multi-GB of delta between the original volume and
the snapshot, so what would make the activation of a thin-provisioned snapshot
faster? Is the metadata stored differently?
Chris
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