Cache Pool size

[lordoxide]

Hey,

 

Quick question, I am new to the cache drive system, let alone a cache pool. I assigned a 480GB drive as a single cache drive. After formatting I was presented with a cache of 480GB available. I then added a 256GB drive to the cache (I pre-cleared it, even though I did not need to), it did not ask me to format the drive, it just immediately added it and my shares started showing 'protected', and the available size updated to 368GB. While conventional math shows this as correct (480 + 256) / 2 = 368, but since this is basically raid 1, shouldn't the available space be 256?

 

Thanks,

Tom

[JorgeB]

Free space reported is incorrect if using different size disks, btrfs limitation.

 

Your max usable space will be 256GB.

[tazire]

Just a quick question I just added a 120gb ssd to my already existing 120gb will this always just mirror the first drive? or should it add to the cache pool to make 240gb available?

 

Being a noob I just expected it to be 240gb but from what im reading the original will just be mirrored to my new one?

[trurl]

Just a quick question I just added a 120gb ssd to my already existing 120gb will this always just mirror the first drive? or should it add to the cache pool to make 240gb available?

 

Being a noob I just expected it to be 240gb but from what im reading the original will just be mirrored to my new one?

The default is for raid1 mirror. The Help for the page where this is configured says

Do not change this unless you know what you are doing!

[tazire]

thanks for the response. and excuse my ignorance