Partitioning an Ext3 root partition.

I wonder if anyone has any pointers for this.

I'm trying to subpartition my root partition (without breaking it) so I can install another OS on my laptop. The trouble is that my root partition is an ext3. I know of no tools (no free tool, I'm too cheap to go out and purchase a copy of PM) that can partition an ext3. Now I do know that I can convert a ext3 to an ext2 with little hassle usually and ext2 can be partitioned by nearly anything. Unfortunately, this is my root partition, which is tricky; It requires fiddling with the OS.

I'm not worried about data loss; I can save everything to my external, and I might just dd|gzip the entire partition. Even still, I'd rather get it right the first time through.

You can try to use gparted or qtparted to resize or shrink your partition, or you can download SystemRescueCd which is linux bootable cd containing both of the tools.

You cannot "sub partition" a partition that already exists, you will need to resize the existing partition to free up space. You can boot from a LiveCD such as knoppix and use (q|qt)parted as mentioned above.

@Flamed_Chip

I know. That's what I'm trying to do. I have a Knoppix DVD with qtParted. The problem is that qtParted is merely a front-end for Parted the standard GNU partition program which does not support ext3 filesystems.

My problem is not with the partitioning (Which I've done before) but the conversion from ext3 to ext2 and back again. This involves disabling the journal. This is tricky at best on a partition with an OS install. Once I've done this, I can use qtParted or gParted to shrink it and add the journal again.

What I'm looking for is a way to remove the journal without damaging the install. I know that it is possible, I just don't have a reliable guide guide at this point. I you can't help, it's ok; I can search elsewhere, but if anybody has any links or advice on ext3 -> ext2 on a partition with an OS install I'd be appreciative.

Here is a guide for Ext3 -> Ext2, and here is one for Ext2 -> Ext3. Google is your friend!

Also, Ext3 resizing is supported by parted, see here.

Sorry, you're correct, I misread the Parted FAQ when I first went through it. Everything looks like it works. QTParted still doesn't support it however without additional libraries.

FYI, however, those instructions for converting between ext2 & ext3 are only for partitions without an OS install. I found them (and others) last week. If you're affecting the root partition, there are additional steps or you'll possibly fry your OS. The details are distro specific and I was hoping for a deeper explaination, but it appears I don't need it.

You don't need to worry about any of those extra steps if you do the conversion while booted from a LiveCD instead of the actual install. The only reason it would be difficult with an OS in the partition is if you were actually using that OS to do the conversion and the partition was mounted. Using something like knoppix will remove these problems.

That's what I thought, but in the example they used a live CD and made a ramdisk image. Now, I'm wondering, if that's because they then needed to boot the OS onto said partition after the conversion? If one were to convert to ext2, make necessary adjustments, then revert back to ext3 without ever booting the OS, would that cause any harm? Why, why not?

(Thank you BTW, gParted seems to work for computer.)

It shouldn't cause any problems no. Removing the journal should not effect the files in any way.