Re: Reiser just bit me! (was: Comparison of filesystems)
On Fri, 2006-04-28 at 20:49 +0100, Digby Tarvin wrote:
> > >
> > >P.S. to include something relevent to the original thread, I have
> > >use both Reiserfs and Ext3, and have never found enough performance
> > >or reliability difference to worry about - so for me the main
> > >advantges of each are:
> > > ext3 - more complere set of tools, such as dump/restore
> >
> > IMO, this is the single most important issue with any
> > of these file systems. They are all good it seems. But the
> > additional support varies widely.
>
> After my earlier comment above, I have just been bitten by a Reiserfs
> bug which I think gives me an even better reason to lean towards ext3
> at the moment...
>
> I originally mis-reported this as a dump/restore problem, because I was
> unable to restore successfully from archive files larger than 2GB, but
> on further investigation today....
>
> 1. scenario
> digbyt@fujitsu# mount
> ...
> /dev/hda14 on /home type ext3 (rw)
> /dev/hda13 on /usr/local type ext3 (rw)
> /dev/sda2 on /mnt/sda2 type reiserfs (rw)
> /dev/sda3 on /mnt/sda3 type ext3 (rw)
> digbyt@fujitsu# ls -l ~digbyt/testfile
> -rw-r--r-- 1 root root 2502686720 2006-04-28 17:03 /home/digbyt/testfile
>
> 2. copy big file to reiser filesystem on USB drive
>
> digbyt@fujitsu# dd if=~digbyt/testfile of=/mnt/sda2/testfile
> 4888060+0 records in
> 4888060+0 records out
> digbyt@fujitsu# ls -l /mnt/sda2/testfile
> -rw-r--r-- 1 root root 2502686720 2006-04-28 19:48 /mnt/sda2/testfile
>
> 3. all looks ok, copy from reiser back to ext3 partion on ide disk:
> 2502686720 bytes (2.5 GB) copied, 219.419 seconds, 11.4 MB/s
> digbyt@fujitsu# dd if=/mnt/sda2/testfile of=testfile
> dd: reading `/mnt/sda2/testfile': Input/output error
> 4194304+0 records in
> 4194304+0 records out
> 2147483648 bytes (2.1 GB) copied, 125.64 seconds, 17.1 MB/s
>
> 3. can't read back from reiser, try copying to an ext3 partition on USB:
> digbyt@fujitsu# dd if=~digbyt/testfile of=/mnt/sda3/testfile
> 4888060+0 records in
> 4888060+0 records out
> 2502686720 bytes (2.5 GB) copied, 225.598 seconds, 11.1 MB/s
>
> 4. Now retry copy from USB to IDE partitions
> digbyt@fujitsu# dd if=/mnt/sda3/testfile of=testfile2
> 4888060+0 records in
> 4888060+0 records out
> 2502686720 bytes (2.5 GB) copied, 156.104 seconds, 16.0 MB/s
>
> 5. Conclusion - for some reason the reiser filesystem allows me to
> write files longer than 2GB, but will not let me read back past
> 2GB into the file:
>
> digbyt@fujitsu# ls -l
> total 4545628
> -rw-r--r-- 1 root root 2147483648 2006-04-28 19:54 testfile
> -rw-r--r-- 1 root root 2502686720 2006-04-28 20:08 testfile2
> digbyt@fujitsu# dc
> 16o
> 2147483648p
> 80000000
>
> This test was done on Debian Etch. The reiserfs on the USB drive was
> formatted on another older system, and was reported as
> reiserfs format "3.5" with standard journal
> vs the "3.6" format created by current Debian tools, and the problem
> does not seem to exist on the "3.6" format filesytems...
Upgrade it. You can just use a remount with -oconvert on the filesystem.
Then you should be able to read the file.
I experienced this problem with a named pipe into a file. I didn't
realize it until I had already deleted and wanted to extract back out.
I was saved by the fact that it was fixed by doing the FS convert to
3.6
--
greg, greg@gregfolkert.net
The technology that is
Stronger, better, faster: Linux
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