Dne 31.12.2015 v 09:40 M.H. Tsai napsal(a):
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
Hi This is completely UNSUPPORTED - you MAY NOT interfere with LV volumes with 'dmsetup'. You can use dmsetup only if you know EXACTLY what's going on. The only recommended usage of dmsetup with lvm2 is - when lvm2 lacks some error path (e.g. fix mess left after failing lvm command). Otherwise there is no point to hijack LVs in the middle of LV operations - i.e. in cluster world state of LV (active/suspend) is tightly related to lock state.
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.
plain unsupported state. You could have been hijacking suspend/resume/remove operation anytime. In fact you could easily block/freeze whole LV but doing random suspends of DM devices in your system. Regards Zdenek _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
