XEN guest // Bootstrapping Slackware

tested on Slackware 14.2 and current

assuming the domU kernel has already been prepared

Virtual disks

guest=slack

mkdir -p /data/guests/$guest/lala/
cd /data/guests/$guest/

either create a raw sparse file

# disk/partition in M not MiB
    dd if=/dev/zero of=$guest.btrfs bs=1M count=0 seek=8191
    dd if=/dev/zero of=$guest.reiser4 bs=1M count=0 seek=8191

# memory in GiB
#dd if=/dev/zero of=$guest.swap bs=1024k count=0 seek=2048

File-systems

then format and mount it

mkfs.btrfs $guest.btrfs
mkfs.reiser4 -dfy $guest.reiser4

#mkswap $guest.swap

Deploy and setup

from the XEN host directly

mount $guest.btrfs lala/
mount $guest.reiser4 lala/
cd /data/guests/
wget https://pub.nethence.com/bin/slack/slackstrap.bash.txt
mv -i slackstrap.bash.txt slackstrap.bash
chmod +x slackstrap.bash

vi /root/mirror.conf

mirror=https://mirror.ihost.md/slackware/slackware64-15.0/

cd /data/guests/$guest/
../slackstrap.bash lala/
#../slackstrap.bash lala/ full
#../slackstrap.bash lala/ hardware

# kvm-only
../slackstrap.bash lala/ kernel

move the packages around for later use

mkdir ../slackpkgs/
mv -f *.txz ../slackpkgs/
rm -f FILE_LIST tagfile
du -sh lala/

# 358M btrfs@ocfs2

if this is a REISER4 file-system, let the guest eventually fsck itself at boot time

    wget https://lab.nethence.com/slackpkgs/libaal-1.0.7-x86_64-2_SBo.tgz
    wget https://lab.nethence.com/slackpkgs/reiser4progs-1.2.2-x86_64-2_SBo.tgz

    installpkg --terse --root lala/ /root/slackpkgs/libaal-*_SBo.tgz
    installpkg --terse --root lala/ /root/slackpkgs/reiser4progs-*_SBo.tgz

Setup manually

proceed manually –or– this is otherwise automated with the slackpost.bash script

cd /data/guests/
wget https://pub.nethence.com/bin/slack/slackpost.bash.txt
mv slackpost.bash.txt slackpost.bash
chmod +x slackpost.bash

define/tune accordingly

vi /root/mirror.conf

mirror=https://mirror.ihost.md/slackware/slackware64-15.0/
zone=Europe/Moscow

# FILE-SYSTEM
fs=btrfs
#fs=reiser4

# VMM
vpartition=/dev/xvda1
serial=hvc0
#vpartition=/dev/vda1
#serial=ttyS0

and proceed

cd /data/guests/$guest/
../slackpost.bash $guest lala/

beware to start this one from rc.inet1 or install and enable rc.inet2

    ls -lF lala/etc/rc.d/rc.inet2 # no exist unless you did full install

    # REC but forcibly installed by slackstrap/minimal
    ls -lF lala/etc/rc.d/rc.sshd # already enabled
grep sshd lala/etc/rc.d/rc.inet1
grep sshd lala/etc/rc.d/rc.local

no kernel what-so-ever for XEN

ls -lF lala/var/log/packages/kernel*

update package cache

echo $dns1
echo $dns2

ls -lF lala/etc/resolv.conf # no exist
cat > lala/etc/resolv.conf <<-EOF
nameserver $dns1
nameserver $dns2
EOF

mount -o bind /dev lala/dev
mount -o bind /dev/pts lala/dev/pts
mount -o bind /proc lala/proc
mount -o bind /sys lala/sys
chroot lala/ bash

ping -c1 opendns.com
cat /etc/slackpkg/mirrors
slackpkg update
history -c

^D
rm -f lala/root/.bash

kvm-only

fix the xen guest serial console, see syslinux

xen-only

deploy and enable TMEM

    mkdir lala/lib/modules/
    tar xzf /data/kernels/5.2.21.domureiser4.modules.tar.gz -C lala/lib/modules/
    echo /sbin/modprobe tmem >> lala/etc/rc.d/rc.modules.local
    ls -lF lala/etc/rc.d/rc.modules.local # enabled already

shared

finish-up — be it for a template or not (see below)

    ls -ldF lala/installpkg-*/ # no exist
    #rm -rf lala/installpkg-*/

    du -sh lala/

    # 367M btrfs@ocfs2
    # mklost+found ...
    umount -R lala/
    rmdir lala/

Template-ready

then either proceed with a brutal network setup

eventually proceed with a brutal network setup – avoid ssh host keys generation for darkstar

beware of escapes in da place

short=SHORT-HOSTNAME

# kvm/libvirt
ip=192.168.122.99/24
gw=192.168.122.1

dns1=192.168.122.1

cat lala/etc/HOSTNAME # darkstar.example.net
echo $short > lala/etc/HOSTNAME

mv lala/etc/hosts lala/etc/hosts.dist
echo -e "127.0.0.1\t\tlocalhost.localdomain localhost" > lala/etc/hosts
echo -e "::1\t\t\tlocalhost.localdomain localhost" >> lala/etc/hosts
echo -e "${ip%/*}\t\t$short.localdomain $short" >> lala/etc/hosts
[[ -n $gw ]] && echo -e "$gw\t\tgw" >> lala/etc/hosts
for dns in dns1 dns2 dns3; do
    [[ -n ${!dns} ]] && echo -e "${!dns}\t\t$dns" >> lala/etc/hosts
done; unset dns

ls -lF lala/etc/rc.d/rc.inet1 # no exist
#mv -i lala/etc/rc.d/rc.inet1 lala/etc/rc.d/rc.inet1.dist
#chmod -x lala/etc/rc.d/rc.inet1.dist

# WARNING ESCAPES ARE IN THERE
cat > lala/etc/rc.d/rc.inet1 <<EOF
#!/bin/bash

echo rc.inet1 PATH is \$PATH

if [[ \$1 = stop || \$1 = down ]]; then
    route delete default
    ifconfig eth0 down
    ifconfig lo down
else
    echo -n lo ...
    ifconfig lo up && echo done

    echo -n eth0 ...
    ifconfig eth0 $ip up && echo done

    echo -n default route ...
    route add default gw $gw && echo done
fi
EOF
chmod +x lala/etc/rc.d/rc.inet1

ls -lF lala/etc/resolv.conf # no exist
#mv -i lala/etc/resolv.conf lala/etc/resolv.conf.dist

for dns in dns1 dns2 dns3; do
    [[ -n ${!dns} ]] && echo -e "nameserver ${!dns}" >> lala/etc/resolv.conf
done; unset dns

don’t forget to put your pubkeys over there

mkdir lala/root/.ssh/
vi lala/root/.ssh/authorized_keys

PASTE PUBKEYS

chmod 600 lala/root/.ssh/authorized_keys
chmod 700 lala/root/.ssh/

–or– see tpl

Guest configuration

cat > $guest <<EOF
kernel = "/data/kernels/vmlinuz"
root = "/dev/xvda1 ro console=hvc0 mitigations=off"
#extra = "init=/bin/bash"
name = "$guest"
memory = 7168
vcpus = 16
#disk = ['tap:tapdisk:aio:/data/guests/$guest/$guest.ext4,xvda1,w']
disk = ['tap:tapdisk:aio:/data/guests/$guest/$guest.reiser4,xvda1,w']
#disk = ['phy:/dev/thin/$guest,xvda1,w']
#disk = ['phy:/dev/drbd/by-res/$guest/0,xvda1,w']
vif = [ 'bridge=xenbr0, vifname=$guest.0' ]
type = "pvh"
EOF

Ready to go

what a pleasure, a clean and minimal bsdish gnu/linux distro

xl create $guest -c

lsmod | grep tmem
watch free -m

eats only 46 MB of RAM after a while and total memory stripped down to 137 MB

root@darkstar:~# free -m
              total        used        free      shared  buff/cache   available
Mem:            137          46          15           0          75          61
Swap:             0           0           0

clean-up and make a new template out of it

rm -f FILE_LIST tagfile *.txz
rmdir lala/
cd ../
newtemplate.bash $guest

Rescue mode

extra = "init=/bin/bash"

mount -o remount,rw /
export TERM=xterm
dmesg | grep hvc

...

sync
mount -n -o remount,ro /
halt -p

Troubleshooting

setterm: cannot (un)set powersave mode: Inappropriate ioctl for device

==> disable that ACPI call from rc.M - see above

mount: mount point /dev/pts does not exist
mount: mount point /dev/shm does not exist

==> re-enable rc.udev

interesting shit happens when you install the l and n sets before a and ap, for the record,

installpkg --root lala slackware64/l/glibc-2.23-x86_64-1.txz...sbin/ldconfig: Warning: ignoring configuration file that cannot be opened: /etc/ld.so.conf: No such file or directory
done

installpkg --root lala slackware64/l/polkit-0.113-x86_64-2.txz...grep: etc/passwd: No such file or directory
grep: etc/group: No such file or directory
done

installpkg --root lala slackware64/n/openssh-7.2p2-x86_64-1.txz...grep: etc/shadow: No such file or directory
done

Resources

How to clone LVM thin provisioning volume? https://serverfault.com/questions/458949/how-to-clone-lvm-thin-provisioning-volume

5.4.17. CONTROLLING LOGICAL VOLUME ACTIVATION https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/logical_volume_manager_administration/lv_activate

CHAPTER 14. LOGICAL VOLUME ACTIVATION https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_logical_volumes/assembly_lvm-activation-configuring-and-managing-logical-volumes


HOME | GUIDES | LECTURES | LAB | SMTP HEALTH | NU | HTML5
Copyright © 2022 Pierre-Philipp Braun