I have been doing research on this a bunch and i have not really been able to figure out a clear answer to my concern.

 

I just set up my unraid server. i have two 8tb HD's, and a 1TB samsung evo nvme. I set up the two HDD's in the array with one for parity, and the SSD i formatted as BTRFS and set it as cache. what i want to know is what is the optimal setting in terms of drive usage for appdata and the other shares? i set appdata, domain, isos, and system to all use cache as primary, with no secondary. the main use of this server will be plex, and i may set up immich for a photo backup and hosting solution. My idea is to make unraid use ONLY the SSD for all docker stuff (and any VMs if i decide to play around with that in the future). as well as set up a media share and download share that will have preferred cache but secondary array (for when i'm downloading something or writing from external disk to speed up the writes). since the SSD will have no mirroring, i'm planning to use the appdata back up plugin to periodically back up the appdata from SSD to the array. Does all of this sound sensible/possible? or am i thinking about this all wrong

14 minutes ago, salvialight said:

preferred cache but secondary array

The old terminology had cache-prefer, but I assume you mean primary:cache instead. The difference is cache-prefer meant the same thing as primary:cache; secondary:array; mover action:array->cache.

 

You would set those shares that are meant to be cached but moved to the array as --

primary:cache; secondary:array; mover action:cache->array.

 

You are correct that you want docker and VM related data on some pool such as cache, with nothing on the array.

 

https://docs.unraid.net/unraid-os/manual/shares/user-shares/#default-shares

13 hours ago, trurl said:

The old terminology had cache-prefer, but I assume you mean primary:cache instead. The difference is cache-prefer meant the same thing as primary:cache; secondary:array; mover action:array->cache.

 

You would set those shares that are meant to be cached but moved to the array as --

primary:cache; secondary:array; mover action:cache->array.

 

You are correct that you want docker and VM related data on some pool such as cache, with nothing on the array.

 

https://docs.unraid.net/unraid-os/manual/shares/user-shares/#default-shares

OK so i am on the right track with this set up. My idea is to set it up as cache-preferred and NO secondary storage, so that the appdata/VM stuff is only and always on the SSD. Is that not a good idea? If i set array as secondary, then won't it just move all of the appdata/VM shares on to the array when mover runs, so that would defeat the purpose of putting them on the SSD in the first place

9 minutes ago, salvialight said:

If i set array as secondary, then won't it just move all of the appdata/VM shares on to the array when mover runs, so that would defeat the purpose of putting them on the SSD in the first place

Only if you set the mover direction to be cache->array.

 

Note that since the cache will not be redundant then you probably want the Appdata Backup plug-in to allow a backup copy of the cache shares to be made to a location on the array.

Just now, itimpi said:

Only if you set the mover direction to be cache->array.

 

Note that since the cache will not be redundant then you probably want the Appdata Backup plug-in to allow a backup copy of the cache shares to be made to a location on the array.

yup that's exactly what i was planning to do with the appdata back up plugin. but yea that's how i would run mover, cuz i generally want my downloads folder to write to cache and then move to array when mover runs. i guess my main question is, is there some problem with just keeping appdata/system/isos/domain folders permanently on the cache drive (its 1TB)? assuming i do use appdata backup plugin to back it up occasioanlly to the array?

You can keep any share you like on the cache as this is controlled at the individual share level.