Ext3 on Windows 2003

[Dan Hoffkins]

Hello,

I have mounted a Red Hat Ext3 partition (which is actually a snapshot of the volume) on my Windows 2003 server. I want to be able to back the files up from this volume, however I cannot get Windows to recognize the file system.

I am using Ext2IFS (www.fs-driver.org) to mount the volume, but I cannot browse it even though it gets a drive letter. The mountdiag.exe utility tells me this:
Here we have an Ext3 file system which has transactions left in its journal. A
pure Ext2 driver must not access such a volume which is in that state (to
prevent data loss!).
You may solve it by mounting it on Linux (which has a kernel with Ext3
support). Be sure that you cleanly dismount it, before you shutdown Linux.
After that the Ext2 IFS software should be able to access the volume.

Would anyone have a procedure to help me fix this? Or be able to recommend another piece of software that may help?

Thanks!

[Ivan Ferreira]

Never tested this, but you may.

There is a mount option for ext3 "noload", that disables the journal.

You may try before taking snapshot:

mount -o noload,remount /mount_point

mount -o remount /mount_point

I don't know if this will change "on the fly" the journal usage, I don't think so, but you may try.

[Dan Hoffkins]

Thanks for the help!

I found this command on the Red Hat forums, do you think this would do the job as well?

mount -t ext2 /dev/sdf1 /mnt

It will mount a volume as ext2 apparently, but I'm worried about going from ext3 to ext2 and data loss/corruption. I'm going to try with a test volume but has anyone executed this command on an ext3 volume an experienced any problems?

Thanks!

[Ivan Ferreira]

That would do the job if you are able to umount the file system, but if you can umount it, then just stop I/O, umount, snapshot, mount as normal.

I think that without umounting it, you won't be able to change from "ext3" to "ext2" or vice versa. The command may not fail but you won't see right information in /proc/mounts.

File system corruption won't occur if you mount ext3 as ext2.

[Dan Hoffkins]

Ok, that makes sense. So if I umount it, snapshot it, then mount the snapshot to my Windows server, all journaling entries should be cleared from my snapshot because I umount'ed first right?

Thanks!

[Ivan Ferreira]

Yes, that is correct and will be the solution if you can umount the file system. This could be hard if the system cannot stop, but if you can, no problems here.

Welcome to the forum, please review:

http://forums1.itrc.hp.com/service/forums/helptips.do?#28

[Dan Hoffkins]

Ok, that seemed to work well. The only hitch was when running umount I had to do a lazy unmount (umount -l). After which I was able to present the volume to my Windows server without any trouble.

The only thing that makes me worried is the lazy unmount; is there any danger to running this command with files still open? On Red Hat I ran LSOF and saw there were maybe several dozen files still open at the time of the lazy unmount.

Thanks!