Messages in this thread |  | | Date | Fri, 1 Nov 1996 23:27:25 -0500 | From | "Theodore Y. Ts'o" <> | Subject | Re: SCSI Sector Size Problem |
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From: "Nicholas J. Leon" <nicholas@binary9.net> Date: Fri, 1 Nov 1996 20:24:51 -0500 (EST)
Oops! The second part of my argument (which I apparently forgot) was that I then remade the filesystem (to compare the bad sectors, *MOSTLY* the same) and then
cat /dev/zero > /mnt/foo
and it also generated the same errors??
Did you use the -c option to mke2fs? And did you check (using dumpe2fs) to see which blocks it marked as bad? And when you say "the same errors", were the sector numbers really **identical**?
# > hdb: read_intr: status=0x59 { DriveReady SeekComplete DataRequest Error } # > hdb: read_intr: error=0x40 { UncorrectableError }, LBAsect=306946, sector=306945 # > end_request: I/O error, dev 03:41, sector 306945
Keep in mind that once an IDE disk starts going bad, the number of bad sectors usually grows exponentially, so blocks which *were* good only a few seconds ago may not longer be good now. Basically, what's going on is that after a the head does a "touch and go" on the disk surface, this kicks lose filings which start ping-poning around the disk, generally causing more damage, and when some of these fragments hit the disk heads, they can cause the heads to crash into the disk again, and cause even more damage....
I usually suggest to users that as soon as they start seeing those errors, they should plan on replacing their disk *soon*, before they lose all of their data. While it's true that there's some work we can do to try to make Linux more robust in the face of disk errors, the real problem is that PC hardware is so cheasy that once it starts failing, a catastrophic disk failure is usually not far behind.
- Ted
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