IDE drive - "hard error reading fsbn..." - recoverable?

[David Fleck]

4.9-RELEASE-p11 system.

Experimenting with cdda2wav this morning, I managed to get my system into 
a completely non-responsive state- no keyboard, mouse, or console 
activity; the machine responded to about 20% of ping packets, with 
many-second delays; attempts to ssh into the box failed.  So I 
power-cycled the machine.

After an apparently normal reboot, I noticed I could no longer access 
certain files:

  dcf>$ ls .mozilla/firefox/dcf/bookmarks.html
  ls: .mozilla/firefox/dcf/bookmarks.html: Input/output error

and these errors were accompanied by kernel warnings:

  Oct 23 16:58:12 grond /kernel: ad0s1e: hard error reading fsbn 29926527 of 9843232-9843263 (ad0s1 bn 29926527; cn 1862 tn 214 sn 15) status=59 error=40

Other files in /home/dcf were affected, also - many seemed to be related 
to firefox, which had been running when the system froze/was rebooted.

I dropped to single user mode and started fsck - and got the following:

** /dev/ad0s1e
** Last Mounted on /home
** Phase 1 - Check Blocks and Sizes


CONTINUE? [yn]
THE FOLLOWING DISK SECTORS COULD NOT BE READ: 9843232, 
9843233, 9843234, 9843235, 9843236, 9843237, 9843238, 9843239, 9843240, 
9843241, 9843242, 9843243, 9843244, 9843245, 9843246, 9843247, 9843248, 
9843249, 9843250, 9843251, 9843252, 9843253, 9843254, 9843255, 9843256, 
9843257, 9843258, 9843259, 9843260, 9843261, 9843262, 9843263, 9843264, 
9843265, 9843266, 9843267, 9843268, 9843269, 9843270, 9843271, 9843272, 
9843273, 9843274, 9843275, 9843276, 9843277, 9843278, 9843279, 9843280, 
9843281, 9843282, 9843283, 9843284, 9843285, 9843286, 9843287, 9843288, 
9843289, 9843290, 9843291, 9843292, 9843293, 9843294, 9843295,


CONTINUE? [yn]

...many, many times, interspersed with as many kernel errors:

ad0s1e: hard error reading fsbn 9843238 (ad0s1 bn 9843238; cn 612 tn 181 sn 55) status=59 error=40
ad0s1e: hard error reading fsbn 9843239 (ad0s1 bn 9843239; cn 612 tn 181 sn 56) status=59 error=40
ad0s1e: hard error reading fsbn 9843240 (ad0s1 bn 9843240; cn 612 tn 181 sn 57) status=59 error=40
ad0s1e: hard error reading fsbn 9843241 (ad0s1 bn 9843241; cn 612 tn 181 sn 58) status=59 error=40
ad0s1e: hard error reading fsbn 9843242 (ad0s1 bn 9843242; cn 612 tn 181 sn 59) status=59 error=40
ad0s1e: hard error reading fsbn 9843243 (ad0s1 bn 9843243; cn 612 tn 181 sn 60) status=59 error=40
...etc.

So I figure somehow I suffered hard drive damage in the system freeze or 
my reboot.  My questions, now, are:

Is this likely a one-time thing, or a symptom of creeping disk death?
   (The 'hard error' messages only started after the reboot.)

If it's one-time, is the disk still usable?  Can I flag the affected 
sectors as bad, and work around them?

How can I best determine the extent of the damage? I'd rather not do a 
manual fsck for a whole afternoon if I can help it.

How best can I recover from the damage?  Many of the affected files appear 
to be in my home directory.  Can I just blow away the entire /home/dcf and 
restore from backup (I think I have those...)?

Thanks in advance for any advice you might have -

--
David Fleck
david.fleck at mchsi.com