[tlug] backing up zaurus filesystem architecture? (warning, lots of data)

[scott <scott@example.com>]

Hi everyone -or those who have a zaurus ;^)

I've been using the cacko rom on my 3200 for a few months now, love it.
However I think I'm going to try openzaurus now, just because running
2.6 kernel on Zaurus looks so neat. I've started taking backups, but I'm
curious about the filesystem- from what I understand the /etc/fstab
and /etc/mtab files tell the kernel the structure of the filesystem. But
the Zaurus filesystem looks strange to me so I thought I would ask you
all about it:

# cat /etc/fstab
/dev/mtdblock2  /               jffs2   ro,noatime      1  1
/dev/mtdblock3  /home           jffs2   defaults,noatime        1  2
none            /dev/shm        tmpfs   size=1m,noauto  0  0
/dev/mmcda1     /mnt/card       auto    noauto,owner    0  0
none            /dev/pts        devpts  gid=5,mode=620  0  0

# cat /etc/mtab
rootfs / rootfs rw 0 0
/dev/root / jffs2 ro 0 0
/proc /proc proc rw 0 0
/dev/mtdblock3 /home jffs2 rw,noatime 0 0
/dev/ram1 /dev minix rw 0 0
none /dev/shm tmpfs rw 0 0
/dev/hda1 /usr/mnt.rom/cf vfat rw,noatime 0 0
/dev/hdc1 /hdd1 ext3 ro,noatime 0 0
/dev/hdc2 /hdd2 ext3 rw,noatime 0 0
/dev/hdc3 /hdd3 vfat rw,noatime 0 0
none /dev/pts devpts rw 0 0
/dev/mmcda1 /usr/mnt.rom/card vfat rw,noatime 0 0

It appears that /dev/mtdblock2 and /dev/root are identical- /dev/root
says -> mtdblock2. But what confuses me is where mtdblock2 actually
*exists*. The internal hard drive is /dev/hdc, with three partitions
only, so I thought that those /dev/mtdblocks are somewhere on hdc, but
doing a full backup of /dev/hdc1 /dev/hdc2 and /dev/hdc3 shows it has
not backed up the files from /home and / (tried doing a recursive find),
therefore /home and / have got to be somewhere else.

The total size of the mtdblock directories are only 121 megs, so I'm
thinking is these mtdblock filesystems are part of the flash ROM. What
I'm wondering is how can I back up /? I thought this would work OK:

tar clvf /mnt/cd/root.tar /

but zaurus tar is quite limited and doesn't include the 'l' (stay on one
filesystem), also no rsync, cp is limited, etc. Any advice for backing
up /? Does the backup/restore program that comes with Zaurus do just
this? I'm just worried if I don't like openzaurus after formatting my HD
if it's going to be tough to restore.

BTW I tried to find an answer to this on http://www.oesf.org/ but this
site has been down for a few days unfortunately.

Cheers,
Scott VanDusen
Tokyo