Restoring Venti from dumped arenas using Qemu

I've been using this script to dump my venti arenas from my laptop to RAID.

When I'm on the LAN I run this by hand as bootes

#!/bin/rc
test -e /n/daph/home || 9fs daph
bk = /n/daph/home/bootes/t23/arenas
if(! test -e $bk)
mkdir -p $bk
if(! test -e $bk)
status = $mk ^missing && exit
/usr/maht/bin/rc/vbackup /dev/sdC0 $bk

and I kept saying to myself - "I must do a test restore".

Naturally fate intervened and my HD decided that I didn't want to read my isect partiton after all and my hand was forced.

So after a couple of false starts trying to do it with the bootable CD I fired up Qemu with a blank 3G image - my arenas are 1.6Gb - bit of headroom, and installed fossil+venti.

I turned it into a cpu/auth with my script to make logging into it a bit easier

and then as bootes
% 9fs daph; cd /n/daph/arenas/
% venti/wrarena sdC0.arenas00
% venti/wrarena sdC0.arenas01
% time venti/wrarena sdC0.arenas02
1.67u 46.65s 496.71r
% ls -l sdC0.arenas02
--rw-rw-rw- M 85 bootes bootes 536870912 Dec 16 06:46 sdC0.arenas02

which seems easy enough, 1Mb sec

boot the laptop from the CDrom, edit plan9.ini to use my qemu is its venti (using -redir tcp:17034::17034

had to add
venti=/dev/sdC0/arenas tcp!*!17034
to qemu's plan9.ini

balls the qemu is sending a reset instead of data - I think there's a problem in there somewhere after a few different tries, fossil/flfmt dies when using my qemu venti as a host too


OK so with the Venti install I added a new disk - recover

My invocation for qemu venti now looks like this :
qemu.exe -L . -m 1024 -hda venti -hdb recover -localtime -M pc -redir tcp:3131::3131 -vnc :8 -snapshot -redir tcp:5356::5356 -redir tcp:17010::17010 -redir tcp:567::567 -redir tcp:17007::17007 -redir tcp:17034::17034

to get my data I did this as bootes


disk/mbr -m /386/mbr /dev/sdC1/data
disk/fdisk -baw /dev/sdC1/data
disk/prep -bw -a fossil /dev/sdC1/plan9
fossil/flfmt -v 22d...ff3 /dev/sdC1/fossil # 22d...ff3 is the score from fossil/last
fossil/conf -w /dev/sdC1/fossil <<EOF
fsys main config /dev/sdC1/fossil
fsys main open -AWP
fsys main
srv -p ricons
srv rico
EOF
fossil/fossil -f /dev/sdC1/fossil


drawtermed in again as me
mount /srv/rico /n/rico
cd /n/rico/usr/maht
tar cp . > /n/daph/home/maht/plan9_usr_maht.tar


You beauty!!