Cpy%Sync column - high disk activity after reboots

Hi all,

I'm trying lvmcache and it seems to work ok. However, after every reboot, I notice quite a long period of disk activity. lvs gives me this output:

% lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
btrfs-spinner bluebook Cwi-aoC--- 582,19g [cache] [btrfs-spinner_corig] 70,11 11,34 82,55

The % gets lower over time and when it reaches 0 the disk activity goes back to normal.

Is this to be expected/normal?
It seems to me the entire cache is checked as if it wasn't cleanly closed on shutdown. I'm currently using writethrough and would like to make sure everything is ok before enabling writeback.

Thanks,
Mathijs

Dne 31.5.2015 v 16:51 Mathijs Kwik napsal(a):

Hi

Cache is always flushing it's content to disk - so if you have the 'writeback' variant and there were some unwritten data which sits only in cache, they are automatically pushed to origin (cached) device - which is likely your disk activity.

Zdenek