Re: File corruption
Firstly I think this is more suitable for debian-user, so I'm BCCing -devel
and CCing -user. Please CC me on any follow-ups.
On Wed, 17 Oct 2001 15:27, Steven Mooij wrote:
> Hello, I'm not a debian developer (yet), but I hope I am allowed to post a
> message here. It is about a potential bug, but I can't send it with the
> BTS, because I don't know which package to file it against.
Firstly what you are describing isn't a debian bug so is not suitable for the
BTS. It's either a kernel issue or a hardware issue.
> On Wed, 17 Oct 2001 00:58:59 Russell Coker wrote:
> > Also there's this new "tainted kernel" thing which is a huge new feature,
> > and
> > there are rumours about Ext3 FS corruption and data loss..
>
> Maybe my problem has something to do with these rumours, maybe not: When I
> copy large amounts of data sometimes some bytes are changed. This must
> sound vague: sometimes, some bytes, but unfortunately this is the case, I
> haven't figured out a reproducable test-situation.
Firstly create a file with a variety of data that's significantly larger than
ram. Eg:
tar cvf /tmp/junk /usr
Then run md5sum repeatedly on it in the following fashion:
while /bin/true ; do md5sum /tmp/junk ; done > /tmp/out
Leave that running overnight and then run the following in the morning:
uniq < /tmp/out
If it gives more than one line of output then your hard drives are not
repeatedly returning the same data to read requests.
There is a potential problem that this error may only occur on certain parts
of the hard drive. Booting with init=/bin/sh and running the following could
be useful in that case:
while /bin/true ; do md5sum /dev/md1 ; done
Doing that all night shouldn't exhaust the kernel scroll-back buffer.
Then if that doesn't show anything then you have to try repeatedly copying a
file and using md5sum to check the result (should be the same after every
copy).
> 2628DB Delft
If your machine is portable I could meet you at a HCC or NLLGG meeting and
check it out. Send private mail if that interests you.
--
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