How do I easily repair a single unreadable block on a Linux disk?
- by Nelson
My Linux system has started throwing SMART errors in the syslog. I tracked it down and believe the problem is a single block on the disk. How do I go about easily getting the disk to reallocate that one block? I'd like to know what file got destroyed in the process. (I'm aware that if one block fails on a disk others are likely to follow; I have a good ongoing backup and just want to try to keep this disk working.)
Searching the web leads to the Bad block HOWTO, which describes a manual process on an unmounted disk. It seems complicated and error-prone. Is there a tool to automate this process in Linux? My only other option is the manufacturer's diagnostic tool, but I presume that'll clobber the bad block without any reporting on what got destroyed. Worst case, it might be filesystem metadata.
The disk in question is the primary system partition. Using ext3fs and LVM. Here's the error log from syslog and the relevant bit from smartctl.
smartd[5226]: Device: /dev/hda, 1 Currently unreadable (pending) sectors
Error 1 occurred at disk power-on lifetime: 17449 hours (727 days + 1 hours)
... Error: UNC at LBA = 0x00d39eee = 13868782
There's a full smartctl dump on pastebin.