Reformatting external harddrive

Polytropon freebsd at
Wed May 13 22:19:28 UTC 2009

On Tue, 12 May 2009 22:04:35 -0400, Daniel Underwood <djuatdelta at> wrote:
> According to the newfs manpages, you can specify a filesystem type
> (-O) and a disktype (-T) for "backward compatibility." It further
> appears that -O can only designate either UFS1 or UFS2.  I don't quite
> know what the -T option designates; i.e., back compatible with "what"?

The -O 2 (default) would be the best solution I think. UFS2 is the
standard in FreeBSD.

And yes, I forgot to mention this: After formatting the drive, you
will surely want to enable soft updates. Use the command

	# tunefs -n enable /dev/da0

to do this. Refer to "man tunefs" for more information, for example
if you wish to set minfree to another than the default value, or
the optimization for either space or time.

The -T <disktype> is mentioned in /usr/src/sbin/newfs/newfs.c line 388
cont. and of course in the getopt() selector at the beginning of the
newfs program.

> (I ask about the -O and -T options becase I would like to use this
> harddrive on both my FreeBSD and my linux machine.)

I'm not sure if Linux is able to use UFS... (I don't use Linux, so
I really can't tell.).

>From Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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