Hello! Documentation states: "Device-mapper allows you, without massive data copying: *) To create snapshots of any block device i.e. mountable, saved states of the block device which are also writable without interfering with the original content;" - from http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.32.y.git;a=blob_plain;f=Documentation/device-mapper/snapshot.txt;h=a5009c8300f3364a98e8982c9697f1dee789346f;hb=HEAD So, assuming I am reading right that it is possible to create snapshot of say SATA disk partition or even md device. I'm trying to achieve this but without much luck: root@ubuntu:~# blockdev --getsz /dev/sda1 9767457 root@ubuntu:~# echo '0 9767457 snapshot /dev/sda1 /dev/ram7 N 1'|dmsetup -vvvvvvv create tstsnap dm version OF [16384] dm create tstsnap OF [16384] tstsnap: Stacking NODE_ADD (252,0) 0:6 0660 dm reload tstsnap OF [16384] device-mapper: reload ioctl failed: Device or resource busy dm remove tstsnap OF [16384] tstsnap: Stacking NODE_DEL (replaces other stacked ops) Command failed root@ubuntu:~# dmesg |tail [ 2729.015213] device-mapper: table: 252:0: snapshot: Cannot get origin device [ 2729.132113] device-mapper: ioctl: error adding target to table root@ubuntu:~# uname -a Linux ubuntu 2.6.32-22-generic #33-Ubuntu SMP Wed Apr 28 13:28:05 UTC 2010 x86_64 GNU/Linux root@ubuntu:~# dmsetup targets mirror v1.12.0 snapshot-origin v1.7.0 snapshot v1.7.0 multipath v1.1.0 striped v1.3.0 linear v1.1.0 error v1.0.1 I guess i miss something but do have no idea what i'm missing -- Best regards, [COOLCOLD-RIPN] -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
