[Failed Measuring - help]

Not sure which Recycle bin to remove (the individual drive, or the pool itself)? I've cleared the individual drives, but there seems to be 16Gb in the pooled recycle that I am not sure that i want to remove/lose.

Did a checkdisk and now have a weird issue where a disk is lost, but is able to be added. See screenshot below.

I'm not sure how I can move forward with this without creating a new pool and moving data manually. If someone can give me a steer that would be a help.

[Failed Measuring - help]

Drive Pool gives me the following error and I have no idea what to do to rebuild my pool.