On Wed, Jan 09, 2008 at 09:45:30PM -0800, Daniel Burrows wrote:
> > resize2fs: Filesystem does not support online resizing
> AIUI this means you didn't create the filesystem with "-O resize_inode",
> so you can't do online resizing. Unfortunately there's no way to change
> this after the filesystem is created (see bug #351720), so you're stuck
> booting into single-user mode and unmounting /var, or making a boot disk
> and running resize2fs from there.
Well, there *is*, but you have to run an off-line program once
(ext2prepare, in the ext2resize package first). The reason why that
program hasn't been integrated into e2fsprogs is because I looked at
the source code, and it was too scary for me to support. I used to
tell people though that while *I* was too chicken to support it, as
far as I knew no one had ever reported data loss, they'd have to
decide on their own whether they felt comfortable using it.
Unfortunately, a few months ago someone actually told me about
ext2prepare corrupting their filesystem, so I can't say that anymore.
I don't know whether the *single* report was due to hardware errors
(and the person getting unlucky), or filesystem corruption that had
been lurking on the filesystem that interacted extremely tragically
with ext2prepare. So use ext2prepare at your own risk. YMMV. Past
results do not indicate future returns, etc.
If you only need to resize your filesystem once, you're better just
doing an offline resize.
P.S. New versions of e2fsprogs request the online resizing inode, so
you don't need to specify -O resize_inode. In fact, which features
are enabled by default can be found in /etc/mke2fs.conf.