Date: Tue, 20 Apr 1999 15:34:26 -0400 (EDT) From: "Crist J. Clark" <cjc@cc942873-a.ewndsr1.nj.home.com> To: freebsd-questions@FreeBSD.ORG (FreeBSD Questions) Subject: Using Raw wd Message-ID: <199904201934.PAA10233@cc942873-a.ewndsr1.nj.home.com>
next in thread | raw e-mail | index | archive | help
I'm having some trouble using a slice on a hard drive as a raw
device. A co-worker would like some space always available to write CD
images. He has a DOS slice on his hard drive (IDE) that he does not
mind taking a ~650 MB chunk out of. He had three slices, one where NT
lived (wd0s1), the DOS partition (wd0s2), and FreeBSD (wd0s3). I took
a chunk out of the DOS parition[0], and made a fourth slice (wd0s4).
Now, my personal preference would be _not_ to put a filesystem on this
slice. It's only ever going to be used to store a CD image, and it
would be cool to just have to,
# mount -t cd9660 /dev/wd0s4 /cdrom
To test your image[1][2].
However, I have been unable to write to the slice as a raw
device. After some troubles learning the intricacies of MSDOS style
partitions, I do now have a partition table that the BIOS is happy
with. But attempts to test write to the slice by using mkisofs, or
just 'tar cvf /dev/wd0s4 something', cause Very Bad Things[3] to
happen. Writing to /dev/rwd0s4 gives the resonse that the filesystem
is read-only. BTW, /dev/wd0s4 and /dev/rwd0s4 do exist.
How can I treat a slice like a raw device? I didn't think I needed to
give it a disklablel or filesystem. Am I wrong? Thanks for any help.
[0] Learning the hard way about MSDOS partition's odd predilection for
'track boundaries.' For this hard drive, this meant that
partitions needed to consist of an integer multiple of 16065
blocks, 63x255 (and not 64x256... whatever, live and learn).
[1] No need to go through vnconfig, or to teach the user of the
machine how to go through vconfig.
[2] Add the apropriate fstab entry and just 'mount /testcd' or the
like.
[3] Complete freeze ups and kernel panics.
--
Crist J. Clark cjclark@home.com
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199904201934.PAA10233>