François 10 August 2007 20:42 EDT

I just tried this on my Ubuntu Feisty install, on both the / and /home fstab entries. The result is that something went wrong, an error of some kind, and the partitions were mounted read-only. This is kind of a problem since then you can't edit fstab to revert the changes.

Of course this happened just as I forgot my live CD's at work. This gave me the opportunity to boot back into my WinXP install (it's been a while) an try ext2 IFS for Windows. (How do you make URLs? the link is: http://www.fs-driver.org/) It worked like a charm -- I was able to access / and change fstab back...

I still don't know what went wrong, I should try each of the three options individually to see what triggers the problem...

wiswaud 14 August 2007 13:04 EDT

it seems that it's the data=writeback part.
The 'ro' option to the kernel makes it mount the partition read-only, which presumably doesn't use the data=writeback option. This is so that fsck can be executed even on the root partition (b/c it's read-only).
Then, later on, the partition is re-mounted read-write. But the filesystem, it seems, doesn't support changing the datamode to writeback on an already-mounted partition, so it remains mounted as read-only. We'd have to mount it read-write to begin with, but then you wouldn't be able to fsck it...
So, leave the data=writeback option *out*.