On Fri, Mar 22 2013 at 11:12am -0400, Andres Toomsalu <andres@active.ee> wrote: > Update! Issue seems to be active only with PERC H800 and MD1200 disks - local raid with PERC H700 and lvm thin lv-s work fine without corrupting on reboot. > > > We stumbled on strange lvm thinly provisioned LV filesystem corruption case - here are steps that reproduce the issue: > > lvcreate --thinpool pool -L 8T --poolmetadatasize 16G VolGroupL1 > lvcreate -T VolGroupL1/pool -V 2T --name thin_storage > mkfs.ext4 /dev/VolGroupL1/thin_storage > mount /dev/VolGroupL1/thin_storage /storage/ > reboot Couple things: 1) mkfs.ext4 does buffered IO so there is no gaurantee the superblock or any other block group destriptors, have actually been committed to non-volatile storage when mkfs.ext4 completes 2) reboot sequence is very distro specific; /storage may not have been unmounted before reboot -- if it was unmounted then all data should've been pushed out to non-volatile storage So if you add this to command before "reboot" do you no longer have missing data after the system reboots?: echo 3 > /proc/sys/vm/drop_caches > # NB! without host reboot unmount/mount succeeds! > > [root@node3 ~]# mount /dev/VolGroupL1/thin_storage /storage/ > mount: you must specify the filesystem type > > Tried also to set poolmetadatasize to 2G, 14G, 15G and pool size to 1T, 2T - no change - corruption still happens. > > Hardware setup: > * Underlaying block device (sdb) is hosted by PERC H800 controller and disks are coming from SAS disk expansion box (DELL MD1200). ... > What could be the issue here? I assume by "reboot" you mean the host (with the PERC card) never loses power? What layers of hardware writeback caching are in place in the H800+MD1200 case vs H700+localraid? _______________________________________________ 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/
