Moving docker image and appdata to faster cache

[taalas]

Hi,

i am currently in the process of adding a second cache pool to my array, using an ssd drive. I have already moved my docker image to the new drive (it was at /mnt/cache/docker.img, is now at /mnt/fastcache/docker.img) while having the docker service disabled and this worked flawlessly. I would now like to move my appdata share from the old cache to the new cache. Situation currently:

• appdata share is set to Only:Cache
• all docker containers point to directories at /mnt/cache/appdata (this used to be a suggestion instead of /mnt/user/appdata)
• I would like to move appdata to /mnt/fastcache/appdata

I wondered whether it would make sense to have to appdata shares (appdata and fastappdata) but decided against it, since most plugins etc. (e.g. appdata backup) seem to be built for one appdata share.

There seem to be different options for moving (while disabling the docker service or stopping the containers):

• Use the mover (can I just switch from Only:Cache to Only:Fastcache or Prefer:Fastcache to move the files or do I have to put them on the array in an intermediate step
• moving the files manually on the command line (mv, rsync,...?)

Any advice on what would be the best/safest way to proceed?

 

Thanks!

[Squid]

Mover would work, but you would have to move to the array, and then back to the cache, and mover is super slow.

 

I'd suggest using the appdata backup plugin to backup your appdata share, then create a new share ("fastappdata") and change the source in the backup settings to reference fastappdata and then restore.

[taalas]

Thanks @Squid, that sounds like a great idea. Am I right in assuming, that the name of the appdata share is not actually important (as in hardcoded somewhere)? I was afraid of breaking some functionality with using a different share as appdata, but hoped that it was just a share like any other.

 

Also, could you elaborate if there is any up/downsite for using /mnt/fastcache/fastappdata instead of /mnt/user/fastappdata? I have read many different opinions about this...