Ext3 users - Jun 2003 - mke2fs incorrectly detects partition size

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Hi all,

I don't know if this is the right list, but here goes what happened 
recently to me.

I have an IDE disk (hda: QUANTUM FIREBALLP AS20, ATA DISK drive / hda: 
39851760 sectors (20404 MB) w/1902KiB Cache, CHS=2480/255/63, UDMA(100)) 
connected to 00:1f.1 IDE interface: Intel Corp. 82801BA IDE U100 (rev 12)

I've decided to make a partition, so I've fired up fdisk and make a new 
one (hda7) of 4GB, as you can see in this line:

/dev/hda7          1170      1679   4096543+  83  Linux

Then I've run mke2fs -j /dev/hda7, mounted it, copied data to it, umount 
it. I've not rebooted.

Now I'm trying to mount it back, after a reboot, and mount refuses to 
mount it, kernel gives me this message:

VFS: Can't find ext2 filesystem on dev ide0(3,7).

Remembering what happened, I noted that the partition got formated like if 
it was just 1GB. All this was done using kernel 2.4.18-27.7.x under RedHat 
7.3

Any idea of what caused this? And hopefully how can I get my data back?

Thanks in advance,

PS: please CC me the responses, since I'm not on this list, thank you.
- -- 
Robinson Maureira Castillo
Gerencia de Sistemas y Tecnologias
INACAP
- --
"Unix is simple and coherent, but it takes a genius (or a programmer at
any rate) to understand and appreciate it's simplicity" - Dennis
Ritchie

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On Tue, Jun 10, 2003 at 03:44:19PM -0400, Robinson Maureira Castillo
wrote:
> 
> I don't know if this is the right list, but here goes what happened 
> recently to me.
> 
> I have an IDE disk (hda: QUANTUM FIREBALLP AS20, ATA DISK drive / hda: 
> 39851760 sectors (20404 MB) w/1902KiB Cache, CHS=2480/255/63, UDMA(100)) 
> connected to 00:1f.1 IDE interface: Intel Corp. 82801BA IDE U100 (rev 12)
> 
> I've decided to make a partition, so I've fired up fdisk and make a
new
> one (hda7) of 4GB, as you can see in this line:
> 
> /dev/hda7          1170      1679   4096543+  83  Linux
> 
> Then I've run mke2fs -j /dev/hda7, mounted it, copied data to it,
umount
> it. I've not rebooted.
That was your problem.  If you had a partition in /dev/hda mounted,
the kernel doesn't reread the partition table.  Normally fdisk warns
you that the partition table wasn't reread, and that you need to
reboot in order for the partition table changes in order to take
effect.
> Now I'm trying to mount it back, after a reboot, and mount refuses to 
> mount it, kernel gives me this message:
> 
> VFS: Can't find ext2 filesystem on dev ide0(3,7).
> 
> Remembering what happened, I noted that the partition got formated like if 
> it was just 1GB. All this was done using kernel 2.4.18-27.7.x under RedHat 
> 7.3
> 
> Any idea of what caused this? And hopefully how can I get my data back?
If you remember the partition table layout before you changed things,
you can reset the partition table, and then you should be able to see
your filesystem again.  (Basically, it was created in whatever the
original /dev/hda7 was located, because the partition table change
didn't take effect when you ran mke2fs and mounted the filesystem.)

						- Ted