I have recently added a 2nd SSD to form my first cache pool. The existing drive was 250gb and the new one 128gb. Initially after install the total size displayed was correct, but now it is almost half? Am I missing something about configuring cache pools or preparing the SSD ?

Default mode is raid1, only 128GB can be used, you can change to single profile to use both.

But why is it showing the size as 189GB?

12 minutes ago, Cosine said:

But why is it showing the size as 189GB?

That happens when using different capacity devices with RAID1, but used and free space will be correct, if using v6.9 or newer.

 

 

Thank you. I think I understand when it happens, I am wondering why it happens.

11 minutes ago, Cosine said:

I am wondering why it happens.

It's because of the way Unraid calculates the total capacity, not long ago the free space would also be incorrect in that circumstance, but that was fixed starting on v6.9, IIRC.

Interesting, thanks!

On 11/19/2021 at 7:25 PM, JorgeB said:

It's because of the way Unraid calculates the total capacity, not long ago the free space would also be incorrect in that circumstance, but that was fixed starting on v6.9, IIRC.

 

Reviving this, because it's the first google result, so maybe interesting for other people. The problem seems to be the same on 6.12.0?

 

13 hours ago, FayeInMay said:

The problem seems to be the same on 6.12.0?

Assuming you are using the default raid1 profile the free/used space are correct, just total capacity will be wrong but that's a known issue with different capacity devices and btrfs.

Sorry I need stuff spelled out to understand. So  is it I still get the full capacity in Raid 1 even though total capacity is incorrect because of the issue or what you are saying @JorgeB is if we want to utilize the total capacity of both cache drives we should switch from Raid 1 to the one you suggested above?

If you want the combined total capacity of different sized disks you must use Single profile.