On Windows, we’ve had the defrag tool and others, that happily works on a drive even while it is in use, even the OS disk.
On Linux, I know of the fsck command but that requires the drive in question to be unmounted. Not great when you want to check a running server. I do not want to stop my server and boot it from USB, just to run a disk check. I can’t imagine that’s what the data centers are doing, either!
Surely some Linux tool exists that can do some basic checks on a running system?
Use
btrfsorzfsand you can do a scrub online, and you aren’t recommended to do offline maintenance except in extreme cases. Or in other words, use a better filesystem and offline maintenance isn’t necessary.