[clug] Ext2 vs Ext3: weird benchmark result

[Nathan O'Sullivan]

> Also, if it is really mounted as ex3 you should see the kernel ext3 messages
> in the kernel message log:
>
> [71789.271868] kjournald starting.  Commit interval 5 seconds
> [71789.272296] EXT3 FS on dm-5, internal journal
> [71789.272310] EXT3-fs: mounted filesystem with ordered data mode.
>
>
>    
It doesn't no - that text will appear on a CONFIG_EXT3_FS=y kernel (if 
rootfstype isnt set) as you'd expect.

I've done some more testing with a second partition, that confirms what 
you are saying - the root partition is staying as ext2 or ext3 based on 
whatever the kernel starts it as. As you suggest, /proc/mounts shows ext2:

$ cat /proc/mounts | grep ext
/dev/root / ext2 rw,noatime,nodiratime,errors=remount-ro 0 0

That was all with Debian 5. Ubuntu 10.04 by contrast seems to report the 
"true" value rather than whats in fstab:

$ cat /proc/cmdline
root=/dev/xvda2 ro rootfstype=ext2 clocksource=tsc

$ dmesg | grep -i ext[23]
Kernel command line: root=/dev/xvda2 ro rootfstype=ext2 clocksource=tsc
EXT2-fs warning (device xvda2): ext2_fill_super: mounting ext3 
filesystem as ext2
VFS: Mounted root (ext2 filesystem) readonly on device 202:2.

$ cat /etc/fstab | grep ext
/dev/xvda2 / ext3 noatime,nodiratime,errors=remount-ro 0 1

$ mount | grep ext
/dev/xvda2 on / type ext2 (rw,noatime,nodiratime,errors=remount-ro)


Thanks for your help, I now feel I understand whats going on.

Regards
Nathan