> About 2 weeks ago I posted an email about my problem with a Quantum AS
> and some freezes I was experiencing on my system.
> The problem was that sometimes the PC freezed with the HD led on. No
> disk access was possible, thus requiring a hard reset. On the next
> reboots (after the hard resets) I noticed that the "UDMA CRC Error
> Count" "RAW_VALUE" increased by 1 and the "VALUE" decreased by 1. This
> was happening at every "freeze".
Yes, I remember.
> I first replaced the IDE cable, then I replaced the motherboard but
> the problem represented. I decided to replace the HD with a new one.
> But the problem represented again.
> Now, I changed all the hardware but the software => This cannot be a
> hardware problem!
I'm sorry to hear that you are still having the problem. Did you get the
same model of hard disk? Or something different?
> I am using a pretty standard RedHat 7.3. All filesystems are EXT3 except one
> partition which uses the Reiser filesystem (used by wwwoffle, a web caching
> program). I noticed that the freezes were frequent on the morning, when the
> "updatedb" (part of the "locate" package) program is started by crond,
> causing a lot of disk activity. I left the "locate" configuration files
> unchanged, so the updatedb program was indexing all the "/var" tree,
> including "/var/spool/wwwoffle" where my web cache is mounted.
> Maybe that the "massive" simultaneous access to some files by updatedb and
> wwwoffle exploited some bug the Reiser file system (or something related to
> it) is causing the locks? I think it is possible... ;/ But this does not
> explain why there is a UDMA CRC error...
> Now a question. Is it possible that hard-resetting the PC in the middle of
> some "weird" access by the Reiser file system or in general by the disk layer
> of the kernel caused the UDMA CRC Errors?
I wish I knew the answer, but I don't. About the best I can do is point
you back to the part of the ATA/ATAPI standard that defines a UDMA CRC
error: (see REFERENCES section of the smartmontools home page). Use the
"search" feature of acroread to look for "CRC". You'll find a section
called Ultra DMA CRC rules.)
I think it is possible that resetting the PC in the middle of Reiserfs
activity might cause this kind of thing to happen, but again this is only
I remember that your system was stable for a long time then started having
problems. Did this coincide with a move to reiserfs, or some other system
Somewhat related: some people have found that reiserfs does not perform
well when used under NFS or when used by many process threads at the same
time. The usual alternative is either JFS or XFS.