[linux-lvm] dm-cache and snapshots

[Syahrul Sazli Shaharir]

Hi,

In dm-cache, how do you do snapshots on a cached LV?

# lvs
LV VG Attr LSize Pool Origin
Data% Meta% Move Log Cpy%Sync Convert
LogVol00 vg_server17 -wi-ao---- 117.19g
LogVol01 vg_server17 -wi-ao---- 78.12g
kvm163_img vg_server17 Cwi-aoC--- 1.05t [DataLVcache]
[kvm163_img_corig] 10.14 12.29 0.00

# lvcreate -s -n /dev/vg_server17/kvm163_img_snap -L 10G
/dev/vg_server17/kvm163_img

Snapshots of cache type volume vg_server17/kvm163_img is not supported.

Thanks.

[Zdenek Kabelac]

Post by Syahrul Sazli Shaharir
Hi,
In dm-cache, how do you do snapshots on a cached LV?
# lvs
LV VG Attr LSize Pool Origin
Data% Meta% Move Log Cpy%Sync Convert
LogVol00 vg_server17 -wi-ao---- 117.19g
LogVol01 vg_server17 -wi-ao---- 78.12g
kvm163_img vg_server17 Cwi-aoC--- 1.05t [DataLVcache]
[kvm163_img_corig] 10.14 12.29 0.00
# lvcreate -s -n /dev/vg_server17/kvm163_img_snap -L 10G
/dev/vg_server17/kvm163_img
Snapshots of cache type volume vg_server17/kvm163_img is not supported.

Hi

Support for snapshot of cached LV is not yet written - so you need to uncache
LV for now.

Regards

Zdenek