I upgraded my CPU and Motherboard and realized my older M.2 SATA Cache drive would no longer work in my new motherboard which only supports NVME M.2 SSDs.

Instead of doing this they way I saw mentioned several times in forum posts (Using mover to move the old cache drive contents on the array, install the new drive, and move everything back....)

I decided to just clone the old Cache Drive (500GB) onto the new NVME Cache Drive (1TB) -- hindsight

I used Clonezilla and actually the process went great and my new cache drive is recognized in Unraid (after some configuration changes) with all of the data there and Docker working off it like nothing changed.

The only issue I have now is the Cache drive only reports it as a 500GB drive. I think this was an option in Clonezilla I missed and it cloned the exact space from the old drive.

Is there a good solution from within Unraid (GUI or CLI) to "extend" the cache drive partition and recover that free unused space on the 1TB drive without reformatting it?

Post the diagnostics to see the current partition layout.

Here they are

tower-diagnostics-20251204-0743.zip

This should work, but make sure you still have the old devices as a backup

Stop the array, click the pool and then "remove pool"

Now delete the old partition layout from the device (this will not delete the data)

wipefs -a /dev/nvme0n1

Then create the new layout starting on the same sector:

sfdisk --quiet --label dos /dev/nvme0n1 <<< 'start=64'

Now on main add a new pool, assign that device, start the array, cache should mount normally but still show 500GB

With the array running type

xfs_growfs /mnt/cache

And that should do it

P.S. The current pool is using 64 starting sector, so we must keep that, for some time now, and for better performance, Unraid partitions SSDs on sector 2048, but for that, you would need to reformat the device and restore the data.

That worked out nicely. Thanks for the help!