On 03/02/2015 04:16 AM, koukou73gr wrote:
Hello, Today I thought I'd experiment with snapshots and cloning. So I did: rbd import --image-format=2 vm-proto.raw rbd/vm-proto rbd snap create rbd/vm-proto@s1 rbd snap protect rbd/vm-proto@s1 rbd clone rbd/vm-proto@s1 rbd/server And then proceeded to create a qemu-kvm guest with rbd/server as its backing store. The guest booted but as soon as it got to mount the root fs, things got weird:
What does the qemu command line look like?
[...] scsi2 : Virtio SCSI HBA scsi 2:0:0:0: Direct-Access QEMU QEMU HARDDISK 1.5. PQ: 0 ANSI: 5 sd 2:0:0:0: [sda] 20971520 512-byte logical blocks: (10.7 GB/10.0 GiB) sd 2:0:0:0: [sda] Write Protect is off sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sda: sda1 sda2 sd 2:0:0:0: [sda] Attached SCSI disk dracut: Scanning devices sda2 for LVM logical volumes vg_main/lv_swap vg_main/lv_root dracut: inactive '/dev/vg_main/lv_swap' [1.00 GiB] inherit dracut: inactive '/dev/vg_main/lv_root' [6.50 GiB] inherit EXT4-fs (dm-1): INFO: recovery required on readonly filesystem
This suggests the disk is being exposed as read-only via QEMU, perhaps via qemu's snapshot or other options. You can use a clone in exactly the same way as any other rbd image. If you're running QEMU manually, for example, something like: qemu-kvm -drive file=rbd:rbd/server,format=raw,cache=writeback is fine for using the clone. QEMU is supposed to be unaware of any snapshots, parents, etc. at the rbd level. Josh _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
