Re: Cannot mount old ext2 cdrom, but e2fsck shows no problems

[Nick Urbanik <nicku@vtc.edu.hk>]

Vincent Stemen wrote:

> On Tuesday 05 June 2001 02:36, Nick Urbanik wrote:
> > Dear folks,
> >
> > I made 18 ext2 cdroms in October 1998 using an old (new at the time) Red
> > Hat system.  Now I can't mount them.  e2fsck shows no problems.  I also
> > can dd them to a file, then mount the file.  But I want to be able to
> > simply access them directly.  Current system: RH 7.1 with all updates.
> >
> > Sorry, I can't remember the exact command I used to create the images.
> >
> > I also want to better understand the output of dumpe2fs, and how to
> > relate this to mount.
> >
>
> I think you are running into a block size issue.  I notice your fs
> block size is only 1024.  See if you can mount it on an IDE CDROM
> drive.

I have tried that before on one RH 7.1 machine and got quite a different
error message (but it still wouldn't mount).

> I ran into the same problem with file systems with a block
> size of 1024 when using the ide-scsi module because it saw the device
> bs as being 4096.  You cannot mount a file system with block size
> smaller than the device.

I think you have hit the nail on the head.  I am not sure how to change the
device block size of my CDROM.

Any suggestions VERY welcome!

I will experiment some more with other IDE CDROMs.  But as things are, it
seems that the easiest way to read the data is to dd it to a file and mount
it.  And I thought using ext2 would give me guarantees of being accessible
from Linux!!!  I am backing up onto --multi-volume tar files on iso9660 file
systems now.

> I would unload the the ide-scsi modules and
> mount it as /dev/hdxx and it mounted just fine.  I started specifying
> the bs to be 4k when creating the file system to backup to CD and the
> problem went away.  The error message was deceiving.  I did not
> discover what it was until I left X windows and tried it from the
> console and finally got an error relating to block size.
>
> - Vincent Stemen

Thank you very much for your helpful reply, Vincent.

> > $ dumpe2fs -h /dev/scd0
> > dumpe2fs 1.19, 13-Jul-2000 for EXT2 FS 0.5b, 95/08/09
> > Filesystem volume name:   <none>
> > Last mounted on:          <not available>
> > Filesystem UUID:          7eb1b040-59f7-11d2-9e35-002018530df2
> > Filesystem magic number:  0xEF53
> > Filesystem revision #:    0 (original)
> > Filesystem features:     (none)
> > Filesystem state:         clean
> > Errors behavior:          Continue
> > Filesystem OS type:       Linux
> > Inode count:              166624
> > Block count:              665600
> > Reserved block count:     33280
> > Free blocks:              142206
> > Free inodes:              153910
> > First block:              1
> > Block size:               1024
> > Fragment size:            1024
> > Blocks per group:         8192
> > Fragments per group:      8192
> > Inodes per group:         2032
> > Inode blocks per group:   254
> > Last mount time:          Fri Oct  2 21:06:45 1998
> > Last write time:          Fri Oct  2 23:53:28 1998
> > Mount count:              3
> > Maximum mount count:      20
> > Last checked:             Fri Oct  2 20:57:46 1998
> > Check interval:           15552000 (6 months)
> > Next check after:         Wed Mar 31 20:57:46 1999
> > Reserved blocks uid:      0 (user root)
> > Reserved blocks gid:      0 (group root)
> >
> > (I originally sent this to the Red Hat list, but there was no response).

--
Nick Urbanik, Dept. of Information & Communications Technology
Hong Kong Institute of Vocational Education (Tsing Yi)
email: nicku@vtc.edu.hk
Tel:   (852) 2436 8576, (852) 2436 8579   Fax: (852) 2436 8526
pgp ID: 7529555D fingerprint: 53 B6 6D 73 52 EE 1F EE EC F8 21 98 45 1C 23 7B