Feature Request: add offline replace to allow speed optimization

[julie777]

I am running replace of a replace on an array in good condition. The machine is idle. The new drive is on a separate controller.

I am only getting 50B/s disk read/write. This is extremely slow. It will take days to finish the replace.

Other operations, balance, defrag, file copy, etc. get between 200 and 300M/s.

[adam900710]

Extra info please. From kernel version to drive models etc.

And slow replace is a problem itself, you should not jump into the conclusion of offline replacement.

[Forza-tng]

@julie777 Normally, replace works at drive speeds similar to dd. If it is very slow there might be some problems. Please show us dmesg output, kernel version, progs version and what type of setup you have. etc.