Hi all, I am using ZFS and "zfs snapshot/send/receive", to send ZFS snapshots to a "mirroring" server, just the incremental changes instead of the full snapshot everytime. I am aware of LVM snapshots but I never used it for incremental mirroring (and did not use them a lot, anyway, so I never looked too much under the hood - maybe I should have..) The kernel documentation makes me wonder whether it is possible to achieve the same with LVM: http://www.mjmwired.net/kernel/Documentation/device-mapper/snapshot.txt According to that, you have access to the COW storage as well: # lvcreate -L 1G -n base volumeGroup # lvcreate -L 100M --snapshot -n snap volumeGroup/base # ls -lL /dev/mapper/volumeGroup-* 93 brw------- 1 root root 254, 11 29 ago 18:15 /dev/mapper/volumeGroup-base-real 94 brw------- 1 root root 254, 12 29 ago 18:15 /dev/mapper/volumeGroup-snap-cow 95 brw------- 1 root root 254, 13 29 ago 18:15 /dev/mapper/volumeGroup-snap 96 brw------- 1 root root 254, 10 29 ago 18:14 /dev/mapper/volumeGroup-base 97 Is it possible to send copies of it to a remote server and apply the changes as described in the doc, using the merge options? The idea is to establish a "rotation regime" and just to send the -cow block device for continuous mirroring. Volker Grabsch, on a German mailing list, wrote about his improved "block-level rsync", https://github.com/vog/bscp He plans to use it for LVM mirroring. I just wondered whether he really has to search the whole block device for changes, if LVM knows about them already. Regards Peter