[9fans] venti...err 2: decompression gave partial block

[Jerome Ibanes <jibanes@eskimo.com>]

I've had great luck running plan 9 from Xen (using a debian kernel
2.6.18-3-xen-686) on Intel hardware with hardware virtualization...
until recently.

I've recently recreated my cpu+fileserver using a more recent iso
(I was using one from January 07 before that) downloaded on March
24.

I've done the following, which I'm pretty sure is the standard
procedure (non-relevant parts removed):

dd if=/dev/zero of=/usr/xen9/plan9.img seek=$((4 * 1024 * 1024 * 1024 -
1)) bs=1 count=1
xm create plan9inst -c
 use DMA for ide drives[yes]:[enter]
 % inst/textonly[enter]
 Task to do [configfs]:[enter]
 File system (fossil, fossil+venti)[fossil]:fossil+venti[enter]
 Task to do [partdisk]:[enter]
 Disk to partition (sd00, sd01)[no default]:sd00[enter]
 Install mbr (y, n)[no default]:y[enter]
 >>>w[enter]
 >>>q[enter]
 Task to do [prepdisk]:[enter]
 Plan 9 partition to subdivide (/dev/sd00/plan9)[/dev/sd00/plan9]:[enter]
 >>>w[enter]
 >>>q[enter]
 Task to do [fmtfossil]:[enter]
 Fossil partition to format (/dev/sd00/fossil)[/dev/sd00/fossil]:[enter]
 Task to do [mountfs]:[enter]
 Fossil partition (/dev/sd00/fossil)[/dev/sd00/fossil]:[enter]
 Task to do [configdist]:[enter]
 Distribution is from (local, net)[local]:[enter]
 Task to do [mountdist]:[enter]
 Distribution disk [no default]:/dev/sd01/data[enter]
 Location of archives [browse]:[enter]
 /% exit[enter]
 Task to do [fmtventi]:[enter]
 Venti arena partitions to use [/dev/sd00/arenas]:[enter]
 Venti index partitions to use [/dev/sd00/isect]:[enter]
 Task to do [copydist]:[enter]
 Task to do [bootsetup]:[enter]
 Task to do [bootsetup]:[enter]
 Enable boot method (floppy, plan9, win9x, winnt)[no default]:plan9[enter]
 Install the Plan 9 master boot record (y, n)[no default]:y[enter]
 Task to do [finish]:[enter]
 Please make sure the install floppy is in the floppy drive and press
enter.^T^Tr

xm create cpu+fileserver -c
 authid: glenda[enter]
 authdom: google.com[enter]
 secstore key: [enter]
 password: google[enter]
 cd /lib/ndb
 mv local local.old
 cat >/lib/ndb/local <<EOF
# /lib/ndb/local
#
# main network database configuration file


#  files comprising the database
database=
    file=/lib/ndb/local
    file=/lib/ndb/common
    file=/lib/ndb/auth

ipnet=google.com ip=10.0.0.0 ipmask=255.255.255.0
    dnsdomain=google.com
    dns=10.0.0.1
    ntp=router
    smtp=router
    authdom=google.com
    auth=cerberus
    cpu=wopr
    fs=wopr

# what's my name:
ip=10.0.0.7 sys=wopr

# localhost
ip=127.0.0.1 sys=localhost dom=localhost

auth=sources.cs.bell-labs.com authdom=outside.plan9.bell-labs.com
EOF
 cd /rc/bin
 mv cpurc cpurc.old

 cat > /rc/bin/cpurc <<EOF
#!/bin/rc
# /rc/bin/cpurc
#
# cpurc for fileserver

echo -n cpu > /env/service
date > /env/boottime

# replace FILESERVER with the name of your file server
# here we start with kfs, your local disk file system
fileserver=kfs

# default authdom
authdom=google.com

# the local domain to be used in the faces database
facedom=google.com

# mount points
mntgen -s slashn && chmod 666 /srv/slashn

# configure ip address
#ip/ipconfig
ip/ipconfig -g 10.0.0.1 ether /net/ether0 10.0.0.7 255.255.255.0

# name translation, cs sets /dev/sysname
ndb/cs
sysname=`{cat /dev/sysname}
ndb/dns -r

# extract info about our network from ndb
ndb/query ipnet google |rc

# parallelism for mk
NPROC = `{wc -l </dev/sysstat}

# The fileserver will also be timeserver with stratum 9
aux/timesync -n -l -S 9

# services available to networks
aux/listen -q -t /rc/bin/service.auth -d /rc/bin/service il
aux/listen -q -t /rc/bin/service.auth -d /rc/bin/service tcp
EOF
 chmod 775 cpurc
 auth/wrkey
 authid: glenda[enter]
 authdom: google.com[enter]
 secstore key: google42[enter]
 password: google[enter]
 cd
 fossil/conf /dev/sd00/fossil >flproto.bak
 cp flproto.bak flproto
 cat >> flproto <<EOF
 listen tcp!*!564
 listen il!*!17008
EOF
 fossil/conf -w /dev/sd00/fossil flproto
 fshalt
 done halting^T^Tr

Then when I try to boot it, I get the following:

Plan 9
127 holes free
001c5000 027a4000 39710720
39710720 bytes free
cpu0: 1196MHz GenuineIntel P6 (cpuid: AX 0x06E8 DX 0xAFE9FBFF)
#l0: xen: 100Mbps port 0x0 irq -1: 506c616e39ff
128M memory: 40M kernel data, 88M user, 713M swap
cpu0: spurious interrupt 101, last 0
sdxen: backend /local/domain/0/backend/vbd/6/2048/ secsize 512 sectors
8388608
#S/sd00/: part plan9 63 8385930
#S/sd00/: part 9fat 63 204863
#S/sd00/: part nvram 204863 204864
#S/sd00/: part fossil 204864 1463489
#S/sd00/: part arenas 1463489 7756617
#S/sd00/: part isect 7756617 8071273
#S/sd00/: part swap 8071273 8385930
time...
venti...err 2: decompression gave partial block: 5947/8192

clump=10770 failed to read correctly: decompression gave partial block:
5947/8192

fatal /boot/venti error: can't sync server: decompression gave partial
block: 5947/8192

fossil(#S/sd00/fossil)...warning: connecting to venti: connection refused
version...time...
init: can't open /adm/timezone/local
init: exec error: venti i/o error block
54874d82df9e781bd451d3a62a76e7f74c6d223e: not connected to venti server
init: rc exit status: init 32: exec

init: starting /bin/rc
init: exec error: venti i/o error block
54874d82df9e781bd451d3a62a76e7f74c6d223e
init: rc exit status: init 33: exec

init: starting /bin/rc
init: exec error: venti i/o error block
54874d82df9e781bd451d3a62a76e7f74c6d223e
init: rc exit status: init 34: exec
[...]

At this point we're stuck in an endless loop, I suspect a bug in Venti, as
the same steps previously prefectly worked to create a cpu+fileserver
(back in January), I can provide the xen configuration files upon request,
but they haven't changed since I've successfully installed a cpu &
fileserver in January.

Please note that I haven't updated Xen or any of the Xen components or my
linux kernel since January either. Finally, installing plan 9 with the
same Xen machine without Venti (for an auth server) works perfectly.


Thank you for looking into this,
Jerome