Bad disk signs....
 

From /var/log/messages( after weird behavior, like su not working):
Unfortunately hda has hda1=/boot and hda2=/
I assume there is no question the disk is bad. Is there any way to
temporarily fix these problems by isolating bad blocks?
I mean the system does work sometimes(I guess as long as one does not attempt to access the bad blocks.)...

Nov 12 21:41:45 linux kernel: end_request: I/O error, dev hda, sector 2130139
Nov 12 21:41:55 linux kernel: end_request: I/O error, dev hda, sector 2130139
Nov 12 21:42:05 linux kernel: end_request: I/O error, dev hda, sector 2130139
Nov 12 21:42:15 linux kernel: end_request: I/O error, dev hda, sector 2130139
Nov 12 21:42:25 linux kernel: end_request: I/O error, dev hda, sector 2130139
Nov 12 21:42:29 linux kernel: end_request: I/O error, dev hda, sector 8687171
Nov 12 21:42:29 linux kernel: ReiserFS: hda2: warning: vs-13070: reiserfs_read_locked_inode: i/o failure occurred trying to find stat data of [52230 58458 0x0 SD]
Nov 12 21:42:29 linux kernel: end_request: I/O error, dev hda, sector 8687171
Nov 12 21:42:29 linux kernel: ReiserFS: hda2: warning: vs-13070: reiserfs_read_locked_inode: i/o failure occurred trying to find stat data of [52230 58458 0x0 SD]
Nov 12 21:42:29 linux kernel: end_request: I/O error, dev hda, sector 8687883
Nov 12 21:42:29 linux kernel: ReiserFS: hda2: warning: vs-13070: reiserfs_read_locked_inode: i/o failure occurred trying to find stat data of [52230 58870 0x0 SD]
Nov 12 21:42:29 linux kernel: end_request: I/O error, dev hda, sector 8688747
Nov 12 21:42:29 linux kernel: ReiserFS: hda2: warning: vs-13070: reiserfs_read_locked_inode: i/o failure occurred trying to find stat data of [52230 59209 0x0 SD]

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