howo add diskspace to paravirt-domUs
dom0> dd if=/dev/zero of=/mnt/storage/xen/diskfile bs=128M count=1
# xm block-attach <Domain> <BackDev> <FrontDev> <Mode> [BackDomain]
dom0> xm block-attach 82 tap:aio:/mnt/storage/xen/diskfile sdd w 0
dom0> ssh sles10
domU> cat /proc/partitions |tail -1 # now new space comes up
8 48 131072 sdd
domU> mkfs.ext3 /dev/sdd # and is usable
howto setup linux in paravirt-domUs
see software-links on top of this site
domU with redhat/fedora: virt-manager, virt-install (part of redhat, fedora, centos)
domU with debian: debootstrap (part of knoppix, grml, debian)
domU fedora/redhat/suse paravirtualized install: boot xenified vmlinuz+initrd + install via network or cd/dvd
domU all OSs: install fully irtualized in HVM-xen or qemu/vmware, later upgrade with paravirt. kernel
howto setup other os in paravirt-domUs
howto set up tty-stuff for para-domU
vanilla 2.6.23: pass “console=hvc0” with the extra-parameter to the domU if you see nothing after booting
better solution/all else: pass “console=/dev/xvc0” to the domU
for interaction, login to the domU: passing “xencons=tty” is a dirty/fast way, more clean is to use /dev/xvc0 - but might also need eidts of /etc/securetty and /etc/inittab to make logins possible
filesystems/software for xen
pure blocks below multiple dom0-hosts: iSCSI (redhat and suse supported), ata over ethernet (aoe), san-luns, network block devices (nbd), enbd
over that something that lets multiple dom0 access the data on it without interfering: ocfs2+evms (suse supported), gfs(2)-clvm (redhat supported), drbd
this is from xen 3.0.4 times, stuff is easier now with xen >3.1
install windows-xp on the bare metal and run it later under xen (didnt work the other way around here), use FAT32 filesystem for easy handling
after booting setup-cd hit F5 until a menu appears and select 'standart pc'. Otherwise xen has problems running the installation later on (didnt shut down here properly, this setting is also required to be able to setup wixp under xen in the first place)
after installation create 2 new hardware-profiles: 'profile bare metal' for starting the installation on hardware, 'profile xen' for xen
on first start under xen new hardware gets discovered.
easy backups of the wixp-installation from linux:
mount /dev/sda2 /mnt/tmp
cat /dev/zero >/mnt/tmp/fillfile # if this stops with comment 'maximum filesize reached' create an other file like this with a different name
# at some point the filesystem is filled up (out of space) and you are done here
rm /mnt/tmp/fillfile* # delete the files, the zeros remain and make gzips job of compressing easy
gzip -3 </dev/sda2 >/mnt/lv_public/xen_sda2_wixpbackup.gz # do the actual backup.
import os, re
arch = os.uname()[4]
if re.search('64', arch):
arch_libdir = 'lib64'
else:
arch_libdir = 'lib'
kernel = "/usr/lib/xen/boot/hvmloader"
builder='hvm'
memory = 1024
name = "HVMwixp"
vcpus=2
vif = [ 'type=ioemu, bridge=xenbr0' ]
disk = [ 'phy:/dev/sda,hda,w', 'file:/mnt/lv_public/cdrom.iso,hdc:cdrom,r' ]
on_poweroff = 'destroy'
on_reboot = 'restart'
on_crash = 'preserve'
device_model = '/usr/' + arch_libdir + '/xen/bin/qemu-dm'
boot="dcan"
sdl=1
vnc=0
vnclisten="10.0.1.1"
vncconsole=1
vncpasswd=''
stdvga=0
serial='pty'
soundhw='sb16'
usb=1
usbdevice='tablet'
keymap='de'
mounting
mount partitions of a domU with partitiontable from dom0
method 1:
apt-get install multipath-tools # or whatever you distro uses. contains the kpartx-tool
kpartx -av /path/to/domu_imagefile # creates a devnode for every partition under /dev/mapper
mount /dev/mapper/loop4p1 /mnt/tmp # mounts the first partition
method 2:
lomount -diskimage /mnt/storage/xen/xm64_gfs1 -partition 1 /mnt/tmp # does the same thing
method 3:
fdisk -l -u /dev/vg1/lv1
mount -o loop,offset=460615680 /dev/vg1/lv1p2 /mnt # or do a 'losetup -o ...' bevore
xennotes + examples
restrict outgoing traffic of a domU
vif = [ 'brigde=bridge0, rate=10MB/s' ] # limit outgoing traffic to 10MB/second
rebuild domU-initrd with block-support
compute mac predictable from hostname
let a PV-domU see that its partitions growed
growing sparse-files
dd if=/dev/zero of=domUimagefile bs=1 count=0 seek=9G # grow sparsefile to 9GB
perl -e 'truncate(“domUimagefile”, 9.*1024.*1024.*1024.)' # grow sparsefile to 9GB
xen support for framebuffer of domU (starting with xen 3.0.4), notes by Mark Williamson
you can run X within the guest directly.
upgrade to 3.0.4, edit Config.mk to change XENFB_TOOLS to =y and do a make-install tools. This'll give you the dom0 components
for accessing the framebuffer.
compile a domU kernel with framebuffer support in (it's selectable in the kernel menuconfig). If you want to be able to run virtual
terminals on the framebuffer,
you'd also need to select the generic Linux options for the framebuffer console. I'd recommend you do this.
domU: /etc/inittab S0:2345:respawn:/sbin/mingetty ttyS0
domU: /etc/securetty or /etc/securettys (whichever you have)
domU configfile: "xencons=ttyS0 console=ttyS0 video=xenfb"
domU configfile: "vfb=['type=sdl']" to get a local display of the domain's framebuffer or vfb=['type=vnc']
or "vfb=['type=vnc,vnclisten=ipaddr']"
several stuff
00:16:3e:xx:xx:xx IEEE range assigned to XenSource Inc
core2duo board multiplicatorfree: asus P5B Deluxe, P5B Deluxe/WiFi-AP and P5W DH Deluxe starting with BIOS 1405
running Windows in HVM, get audio out of it with a sound server like pulseaudio.
An example debian-interfaces config entry for a bridge:
auto xbr0
iface xbr0 inet dhcp
bridge_fd 0
bridge_maxwait 0
bridge_helo 0
bridge_ports eth0
Manual creation of a simple bridge with enslaved eth0:
brctl addbr xbr0
ifconfig eth0 0.0.0.0 up
brctl addif xbr0 eth0
ifconfig xbr0 10.0.0.1 netmask 255.255.255.0
Advanced manual bridge:
brctl addbr xbr0
brctl setfd xbr0 0
brctl sethello xbr0 0
brctl stp xbr0 off
ifconfig eth0 0.0.0.0 up
brctl addif xbr0 eth0
ifconfig xbr0 10.0.0.1 netmask 255.255.255.0