On Wed, May 20, 2009 at 9:28 PM, Matt LaPlante <cybrmatt@xxxxxxxxx> wrote: > On Wed, May 20, 2009 at 9:17 PM, Eric Sandeen <sandeen@xxxxxxxxxx> wrote: >> Matt LaPlante wrote: >>> According to the Ext4 howto >>> (http://ext4.wiki.kernel.org/index.php/Ext4_Howto#Converting_an_ext3_filesystem_to_ext4), >>> "It is possible to mount both ext3 (and ext2, in kernels 2.6.28 and >>> later) filesystems directly using the ext4 filesystem driver." So >>> this means, if I'm reading it correctly, that a kernel built with ext4 >>> support should be able to mount and manage ext[234] filesystems. Is >>> that correct? If so, are there any limitations on this support? >>> >>> I'm running Ubuntu Jaunty with some custom-built 2.6.29.4 kernels and >>> grub2. I seem to have no problem booting from ext4 disks, so the ext4 >>> support is definitely there and functioning. I had hoped the ext3 >>> support meant I could build the kernel with ext4 only and carry on as >>> usual with my ext3 partitions. Unfortunately doing so causes the ext3 >>> partitions to fail to boot. So... >>> >>> booting ext3 with ext3 in the kernel=fine >>> booting ext4 with ext4 in the kernel=fine >>> booting ext3 with ext4 (only) in the kernel=not fine >>> >>> Is this a problem or was it never intended to work? >> >> It should work... >> >> It'd be more helpful if you could include details on exactly how it >> failed, but if Ubuntu builds ext4 as a module, perhaps the initrd >> creation sees root as ext3 and doesn't bother to put ext4 in the initrd? > > ext4 was compiled in directly, it was not a module (this wasn't an > ubuntu kernel; it was stock). I can try to get a stack trace with > netconsole if it gets far enough to function. It looks likes the magic touch was to add rootfstype=ext4 to the kernel command line. Prior to this the ext4 only kernel wasn't finding the disk, but with it attached it now appears to boot successfully. Maybe worth adding a note to the wiki? > >> >> -Eric >> > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
