this is obsolete doc -- see http://doc.nethence.com/ instead
How to rescue a FreeBSD 8.3 powered Dedibox SC (gen1 & gen 2)
Problem is, the Ubuntu LiveCD (the only one provided by online.net, unfortunately) doesn't provide read-write support for the UFS2 file system type (CONFIG_UFS_FS_WRITE=y is obviously missing in the linux kernel configuration).
Prepare your environment
Start the rescue system (Ubuntu amd64) and proceed,
sudo su -
Note that it's the BSD slide you would have to mount, not the DOS partition dedicated to FreeBSD, check with,
dmesg | less ==> search for 'sda'
[ 2.029969] sd 0:0:0:0: [sda] 976773168 512-byte logical blocks: (500 GB/465 GiB)
[ 2.030036] sd 0:0:0:0: [sda] 4096-byte physical blocks
[ 2.030201] sd 0:0:0:0: [sda] Write Protect is off
[ 2.030260] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 2.030312] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 2.031914] sda: sda1
[ 2.031917] sda1: <bsd: sda5 sda6 >
[ 2.032844] sd 0:0:0:0: [sda] Attached SCSI disk
so you can always mount read-only if you want,
mount -t ufs -r -o ufstype=ufs2 /dev/sda5 /lala/
Read-write workaround using Qemu
apt-get install qemu
qemu-system-x86_64 -no-kvm -hda /dev/sda -cdrom FreeBSD-8.3-RELEASE-amd64-bootonly.iso -curses -boot d
note. adding the '-no-kvm' option is important otherwise the underlying system (Ubuntu LiveCD) crashes.
6 (shift and 6 on french keyboard, the layout has passed through) --> boot loader prompt
OK boot -s
note. your file system (here /dev/ad0s1a) get's mounted automaticly, you just have to fsck and re-mount it read-write.
fsck -y /dev/ad0s1a
mount -o rw /
and proceed with your fixes.
Once you are done you can simply,
shutdown -p now
and you will get out of Qemu (otherwise you should have to),
# Ctrl+Alt+2 to open QEMU monitor and 'quit'
# or Ctrl+A+C when you're using -nographics
Alternatives through the network assuming you've got another box close-by at online.net:
- using iSCSI but the tgt module doesn't seem to be available,
- using dd through the network.
Error trying to mount FreeBSD/UFS partition from FreeNAS: http://askubuntu.com/questions/85189/error-trying-to-mount-freebsd-ufs-partition-from-freenas
Gentoo: Mounting UFS2: http://geek00l.blogspot.fr/2007/02/gentoo-mounting-ufs2.html
Mounting UFS in read/write under Linux (debian): http://ghantoos.org/2009/04/04/mounting-ufs-in-readwrite-under-linux/
QEMU Emulator User Documentation: http://wiki.qemu.org/download/qemu-doc.html