Bruce Cran wrote:
> On Sat, 12 Feb 2011 01:54:58 +0100
> "Julian H. Stacey" <j...@berklix.com> wrote:
>
> > -O filesystem-type
> > Use 1 to specify that a UFS1 format file system be
> > built; use 2 to specify that a UFS2 format file system be built. The
> > default format is UFS2.
> > If anyone fancies looking deeper, please do :-)
>
> I checked with dumpfs that memstick.img is UFS1.
>
> Also, mounting /dev/md0 confuses the kernel into ultimately panic'ing,
> since /dev/md0a is the proper slice.
I'm suprised it mounts. Not suprised it crashes.
> For the mfsroot.gz file from the
> CD ISOs:
>
> # mdconfig -a -f mfsroot
> md0
> # mount /dev/md0a /mnt
> # ls /mnt
> ls: /mnt: Bad file descriptor
> # cd /mnt
> cd: /mnt: Not a directory
> # vim /mnt
>
> panic: ffs_read: type 0
It's not so obvious but in man mdconfig, there's no "[]" around "-t
type", I read that as "-t something" is mandatory, (though it starts
without for you ... & I suspect -t default is malloc, though manual
doesnt say that, but look what manual says re. malloc ... panic ).
I use "-t vnode", which doesn't crash here on 8.1-RELEASE i686:
mdconfig -a -t vnode -f FreeBSD-8.2-RC3-amd64-memstick.img
mount /dev/md0a /mnt
cd /mnt
tar cf - . | ( cd /pri/FreeBSD/releases/amd64/ISO-IMAGES/8.2\
/FreeBSD-8.2-RC3-amd64-memstick && tar xf - )
dumpfs /dev/md0a # UFS1
mdconfig -a -t vnode -f FreeBSD-8.2-RC3-amd64-livefs.iso
mount -t cd9660 /dev/md1 /mnt1
cd /mnt1
tar cf - . | ( cd /pri/FreeBSD/releases/amd64/ISO-IMAGES/8.2\
/FreeBSD-8.2-RC3-amd64-livefs && tar xf - )
mdconfig -a -t vnode -f FreeBSD-8.2-RC3-amd64-disc1.iso
xs mount -t cd9660 /dev/md2 /mnt2
cd /mnt2
tar cf - . | ( cd /pri/FreeBSD/releases/amd64/ISO-IMAGES/8.2\
/FreeBSD-8.2-RC3-amd64-disc1 && tar xf - )
cd / ; umount /mnt2 ; umount /mnt1 ; umount /mnt
mdconfig -d -u 2 ; mdconfig -d -u 1 ; mdconfig -d -u 0
Analysing sizes:
ls -l
723834880 FreeBSD-8.2-RC3-amd64-disc1.iso
348796928 FreeBSD-8.2-RC3-amd64-livefs.iso
1087467520 FreeBSD-8.2-RC3-amd64-memstick.img
cd /pri/FreeBSD/releases/amd64/ISO-IMAGES/8.2 ; du -s -k /mnt* *
988708 /mnt # memstick.img
985807 /mnt1 # livefs.iso
705444 /mnt2 # disc1.iso
999340 FreeBSD-8.2-RC3-amd64-memstick
1023032 FreeBSD-8.2-RC3-amd64-livefs
711640 FreeBSD-8.2-RC3-amd64-disc1
df /mnt
Filesystem Size Used Avail Capacity Mounted on
/dev/md0a 1.1G 1.0G -14M 101% /mnt
umount /mnt ; tunefs -m 0 /dev/md0a
tunefs: minimum percentage of free space changes from 8% to 0%
tunefs: should optimize for space with minfree < 8%
df /dev/md0a
Filesystem Size Used Avail Capacity Mounted on
/dev/md0a 1.1G 1.0G 73M 93%
cd /pri/FreeBSD/releases/amd64/ISO-IMAGES/8.2 ; /bin/pwd
mount | grep /usra
/dev/ad4s4e on /usra (ufs, NFS exported, local, soft-updates)
dumpfs /dev/ad4s4e | head -1 # UFS2
Note du on UFS1 stick (988708) is near the same as tree
copied by tar to UFS2 hard disc (999340), so its not the
differerence between UFS1 & UFS2 that wastes the space
(though good guess & thanks for suggesting it pushed me to
investigate more :-)
We are distributing 7% null space:
Mainly because the file system is too big. We probably don't
need 7% free space on stick just to install or repair,
though that might be useful (if slow) for demos )
+ Also each file will have unused bytes at end, (but so will
livefs.iso have padding per file & not near so bloated,
albeit probably some other fragment size. Per my first post:
> > 2K blocks of nulls.
> > FreeBSD-8.2-RC3-i386-disc1.iso: 565
> > FreeBSD-8.2-RC3-i386-livefs.iso: 905
> > FreeBSD-8.2-RC3-i386-memstick.img: 34521
As a sample test of what makefs produces:
makefs /tmp/bla /usr/share
Extent size set to 8192 block size 8192, fragment size 1024
du -s -k /usr/share # 54 108
ls -l /tmp/bla # 54 927 360
df /tmp/bla
Filesystem Size Used Avail Capacity Mounted on
/dev/ad0s2e 520M 55M 423M 12% /tmp
# PS Note df lies 520M - some bug as not a node ?
mdconfig -a -t vnode -f /tmp/bla # md2
df /dev/md2*
Filesystem 1K-blocks Used Avail Capacity
/dev/md2 51175 48723 -1642 103%
tunefs -m 2 /dev/md2
minimum percentage of free space changes from 8% to 2%
df /dev/md2*
Filesystem 1K-blocks Used Avail Capacity
/dev/md2 51175 48723 1429 97%
Conclusion: makefs leaves 2+3=5% here.
memstick.img is created by /usr/src/release/scripts/make-memstick.sh
which (as above test) at present calls makefs without any tuning parameters
Maybe t should have some parameters ? eg:
makefs -m 1030000000 -b 1% ${tempfile} ${1}
Julian
--
Julian Stacey, BSD Unix Linux C Sys Eng Consultants Munich http://berklix.com
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