Or do I have to find a backup?
It had thousands of reallocated sectors.
I ran badblocks
on one partition but not others. Does that change the result?
I'm using Ubuntu. Some partitions are ntfs and some are ext4, if that matters.
Edit:
I believe the the bad sectors are because of it fell down to the floor for many times.
The first partition is a Ubuntu installation (for boot repair, or using Ubuntu on someone else's computer, etc), which has nothing important and I didn't use it for maybe at least a year. I didn't feel anything strange until one day I failed to boot a computer using it.
I ran badblocks
on two partitions, and found thousands of errors mostly only on that partition. But it is very slow when reading some files on the second partition, which is why I'm concerned.
I didn't check other partitions yet because it becomes obvious I will replace this disk, and I'm afaid of making things worse by reading and writing for more times.