[linux-lvm] Any way to speed up activation of volumes with snapshots?

[Chris Friesen]

On 09/14/2015 12:05 PM, Chris Friesen wrote:
> 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.)

As a side question, currently we have a script which runs "vgchange -ay <vg>", 
which will activate the VG.

This script appears to activate the LVs within the VG serially rather than in 
parallel.  Does it do any processing to determine in which order to activate the 
LVs?

The reason I ask is that we have an overall timeout on the activate phase, after 
which we'll put any un-activated LVs into an error state.  It would be a shame 
to try to activate a snapshotted LV first, and then timeout without activating 
any of the non-snapshotted LVs.

Chris