Quaros

Thank you for the advice! I have executed the steps you provided and now the new SSD is resilvering nicely. Curious as I am, what is the reason this is happening and will this also happen when I replace the 'old' SSD in the cache pool after resilvering of the new one?

I have added the diagnostics zip file after I did the following: 1. Started the server 2. Started the array with 1 working cache SSD 3. Stopped the array 4. Added the new SSD to the ZFS pool via the GUI 5. Tried to start the array (generating the error message of this forum post) morpheus-diagnostics-20240419-1222.zip

I am trying to replace an almost failing SSD from a ZFS 'mirror' cache pool on Unraid 6.12.6: 1. Stopped the array 2. Removed the failing SSD from the cache 3. Started the array 4. Shutdown the server 5. Physically replaced the failing SSD with a new one with the exact same brand, type and size. 6. Started the server 7. Added the new SSD to the cache 8. Tried to start the array. Got the error message Wrong Pool State - cache invalid expansion (via GUI). I thought that by adding a new SSD to the pool, the resilver process would start automatically? How to proceed from this point onwards without losing the data on the only old vallid SSD in the cache zpool?