[linux-lvm] Could we manually suspend the origin before taking dm-thin snapshots?

[M.H. Tsai]

Hi All,

I found an issue when taking dm-thin snapshots: LVM doesn't send
create_snap messages if the origin was already suspended, and LVM
doesn't report any error.

lvcreate vg1 --type thin --thinpool tp1 --virtualsize 1g
dmsetup suspend vg1-lv1
lvcreate vg1/lv1 --snapshot -an

This is due to commit a900d150 moves messaging from resume to suspend,
then LVM skips the suspend phase in this case. I'm not sure whether it
is a legal operation for LVM, but if LVM supports this feature, then
users can control the suspend timing.


Thanks,
Ming-Hung Tsai