[dm-devel] create lvm2 snapshot will take a long time while large IO on origin lv(till large IO ends)

[Phillip Susi]

On 4/28/2010 11:24 PM, Busby wrote:
> it seems the vgs suspend because the lvcreate cmd don't unlock the
> flock, but why the lvcreating of snapshot lv will be suspended while the
> origin is on big data IO?

Because when creating a snapshot it tries to flush any dirty buffers so
that the origin is in a consistent state at the time the snapshot is
created.  This is done to minimize the chance that the filesystem on the
snapshot will be corrupt.