Some questions about cache and appdata

[lutiana]

Hello everyone,

 

I am adding a cache drive to my array, just a single 500Gb NVME WD Red drive, no redundancy as I simply need it to speed up copies and have the mover seto to run once every 8 hours. The data that will flow through it is not critical, and if it gets lost due to failure it's not a big deal.

 

That said, I am trying to understand why the app data is recommended to be on the cache drive? Fix common problems calls this out as a hard warning if it's set to not cache. I get that this would speed up docker performance, but in my situation that would essentially put all my app data at risk, since the cache drive is not redundant.

 

Am I missing something about the cache preferred setting? Does the mover also copy that to the spinning disks when it runs? If not, then why not? Or am I lacking an understanding of how the docker stuff works? Is the unique docker data not at risk with the cache drive failing?

 

Thanks for the help on this?

[itimpi]

It is recommended to put appdata on the cache both for increased performance of Docker containers and also because it can mean that array drives can  then typically be spun down a lot of the time,.  Many people then use the CA Backup plugin to do periodic backups of this share to the Main array,

 

3 hours ago, lutiana said:

have the mover seto to run once every 8 hours.

Mover is really designed for idle hours so running it overnight is more typical.