[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [dm-devel] How to force a snapshot status to valid when I know very well it's valid?



On Fri, Dec 21, 2012 at 11:13 PM, Alasdair G Kergon <agk redhat com> wrote:
> On Fri, Dec 21, 2012 at 10:54:21PM +0000, Greg Stark wrote:
>> took about 30 minutes. I don't know why or what happened there. But it
>
> Big snapshots take a long time to load - the whole cow area has to be
> scanned to generate the list of blocks represented on it.

Hm. I didn't remember this happening previously but I had just doubled
the size of the cow and I might be wrong about it too.

I have another question while I'm here and people are being so
helpful. Is there a way to grow the size of the actual snapshot
device? Not the cow table but the device that the snapshot is
presenting? If I change the size of the underlying device I don't
think it changes the size of the snapshot and if I extend the snapshot
it just changes the size of the cow table. It seems like it should be
possible to add another dm mapping for the added space using a simple
linear mapping.

[btw Alasdair, Hi! We met at FOSDEM and discussed filesystem/dm synchronization
primitives that would help Postgres have more lightweight checkpoints]

-- 
greg


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]