Hi You need to suspend and resume the origin device after create message and before attaching the snapshot. > Hello! > > I tried to test multisnapshots but unfortunately got some errors. > Here is what I did: > > 1) Build vanilla linux-2.6.33 kernel using Ubuntu Desktop 9.10 > config-2.6.31-19-generic config file with > CONFIG_DM_MULTISNAPSHOT=m > CONFIG_DM_MULTISNAPSHOT_MIKULAS=m > CONFIG_DM_MULTISNAPSHOT_DANIEL=m > lines added and with patches from http://people.redhat.com/mpatocka/patches/kernel/new-snapshots/r16/ > imposed. > > 2) reboot with new kernel > > 3) # modprobe dm-store-mikulas > > # modprobe dm-multisnapshot > > # pvcreate /dev/sdb > > # vgcreate vg1 /dev/sdb > > # lvcreate --size=500M --name=lv1 vg1 > > # lvcreate --size=500M --name=lv2 vg1 > > # dd if=/dev/zero of=/dev/mapper/vg1-lv2 bs=4096 count=1 > > # echo 0 `blockdev --getsize /dev/mapper/vg1-lv1` multisnapshot \ > /dev/mapper/vg1-lv1 /dev/mapper/vg1-lv2 16 0 mikulas 0\ > | dmsetup create ms > > # dmsetup message /dev/mapper/ms 0 create dmsetup suspend ms dmsetup resume ms > # echo 0 `blockdev --getsize /dev/mapper/vg1-lv1` multisnap-snap \ > /dev/mapper/vg1-lv1 0 | dmsetup create ms0 > > At this point I got the next error: > device-mapper: reload ioctl failed: No such file or directory > Command failed > > And these lines appeared in dmesg: > [ 6876.506623] device-mapper: table: 252:3: multisnap-snap: Snapshot with this id doesn't exist > [ 6876.506629] device-mapper: ioctl: error adding target to table > > Could you check all the steps I performed right and what could cause > those error messages? > > -- > Best wishes, > Mikhail Klepachevskyy But rather, you could use userspace support for shared snapshots, it makes the use much easier, you can use lvcreate, lvremove, lvresize commands: for lvm-2.02.54: http://people.redhat.com/mpatocka/patches/userspace/new-snapshots/lvm-2.02.54/ for lvm-2.02.60: http://people.redhat.com/mpatocka/patches/userspace/new-snapshots/lvm-2.02.60/ for lvm-2.02.62: http://people.redhat.com/msnitzer/patches/multisnap/lvm2/LVM2-2.02.62/ Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
