Pooled Cache question

[madpoet]

I've got a 500GB SSD currently for cache but got a good deal on a 1TB.  Can I just add it in and pool them or do they have to be the same size?

[JonathanM]

I've got a 500GB SSD currently for cache but got a good deal on a 1TB.  Can I just add it in and pool them or do they have to be the same size?

The default configuration will result in a RAID1 pool with a total protected capacity of 500GB. So, yes you can pool them, but if you are after more storage capacity you will need to add another 500GB of capacity to the pool to enable the rest of the 1TB space. You could add another 500GB drive to do that. 2 - 500GB and 1 - 1TB pooled will result in 1TB of protected storage.

 

If you want to disable the redundancy protection and just add the 2 capacities together you will need to manually change the balance type to RAID0.

[madpoet]

Yeah looking for space. When you say manually change where would I do that? And will I lose existing data?

[JorgeB]

This procedure assumes your current cache drive is BTFRS and won’t delete any data but it's always a good idea to backup just in case.

 

Add the 1TB SSD to the cache pool, start array, wait for balance to finish, this will take some time depending on how much data you have, when there’s no more pool read/write activity it’s done.

 

Go to cache webpage and on balance status type:

 

-dconvert=raid0 -mconvert=raid1

 

This will also take some time depending on data size but you can use the pool in the meantime.