I have a software RAID5 array (Linux md) on 4 disks; the OS is OpenSUSE 12.3.
Recently I replaced a disc with a larger one (fail disc, remove it, add new disc). The capacity of the array has not yet increased as I didn't replace all discs. Now the new one seems to be bad and I want to replace it with the old one. Can I simply remove the new one (fail, remove) and replace it with the unchanged old one or should I format the old one before adding it to the array? The array has a bitmap.
What would happen if I simply shut down the machine and replaced the discs without using