Docu on CentOS

Some links:

CentOS 5

These are just notes taken during the installation, it is not meant as a howto or something like that

Hardware Dell 1950

CentOS 5 X86_64, Minimal system

Additional Packages

Minimal System installed via kickstart, packages:

# Packages groups/list
%packages --resolvedeps --ignoremissing

openssh
openssh-server
wget
perl-libnet
perl-MIME-Base64
perl-URI
perl-Digest-MD5
perl-libwww-perl
perl-XML-Parser
perl-DBI
perl-Crypt-SSLeay
lsof

Post Install, get the following packages

Some of these are not needed, has to be cleaned:

yum install\
gcc make zlib-devel zlib python-devel curses libncurses-devel ncurses-devel openssl openssl-devel \
`yum search xorg-x11|grep dev|grep x86_64|awk -F . '{print $1}'` \
bridge-utils tetex tetex-latex transfig libtool-ltdl dev86 glibc-devel

xen 3.1.2-rc from mercurial

hg pull ...
cd xen-3.1
wget http://www.broadcom.com/docs/driver_download/NXII/linux-1.5.10c.zip
unzip, use broadcom sources for 
make world
make install
depmod 2.6.18-xen
mkinitrd -v -f --with=aacraid --with=sd_mod --with=scsi_mod  --with=megaraid_sas /boot/initrd-2.6.18-xen.img 2.6.18-xen

change/add /boot/grub/menu.list:

 title CentOS (xen-3.1.2-rc2 2.6.18 compiled)
       root (hd0,0)
       kernel /xen-3.1.gz
       module /vmlinuz-2.6-xen ro root=/dev/md1
       module /initrd-2.6.18-xen.img

Boot into your new system:

[root@kribbe ~]# xm dmesg

__  __            _____  _   ____              ____
\ \/ /___ _ __   |___ / / | |___ \    _ __ ___|___ \
 \  // _ \ '_ \    |_ \ | |   __) |__| '__/ __| __) |
 /  \  __/ | | |  ___) || |_ / __/|__| | | (__ / __/
/_/\_\___|_| |_| |____(_)_(_)_____|  |_|  \___|_____|

http://www.cl.cam.ac.uk/netos/xen
University of Cambridge Computer Laboratory

Xen version 3.1.2-rc2 (root@nikhef.nl) (gcc version 4.1.1 20070105 (Red Hat 4.1.1-52)) Tue Nov 13 15:02:14 CET 2007
Latest ChangeSet: unavailable
.
.
.
(XEN) HVM: VMX enabled
(XEN) VMX: MSR intercept bitmap enabled
(XEN) CPU0: Intel(R) Xeon(R) CPU            5150  @ 2.66GHz stepping 06
.
.
.

Note on: Network Problems Broadcom drivers have problems, network is OK when xend started without network bridges, see /etc/xen/xend-config.sxp

Starting bridge with: /etc/xen/scripts/network-bridge start results in a not working network configuration in dom0.

see network-bridge causes network to hang

LVM 2

Due to performance reasons VMs should be installed in LVMs. For recovering a LVM in a Raid-1 see:Recovery of RAID and LVM2 Volumes

Installed Version:

Installed Packages
Name   : lvm2
Arch   : i386
Version: 2.02.16
Release: 3.el5
Size   : 5.5 M
Repo   : installed
Summary: Userland logical volume management tools

NOTE: for having the live-migration-posibility we have to look at Cluster-LVM or something like that.

To get started ....

Setting up LVM2 on kribbe

Using /dev/srv resp. /dev/md3 for LVM we have to:

comment out /dev/md3 in /etc/fstab
umount /dev/srv (only once)
Creating the physical volume and XenVG Volumegroup:

[root@kribbe ~]# pvcreate /dev/md3
 Physical volume "/dev/md3" successfully created
[root@kribbe ~]# vgcreate XenVG /dev/md3
 Volume group "XenVG" successfully created

Within this volume-group we can now manage the partitions for the virtual maschines using lvcreate, lvresize, .... commands

Example: lvm for a CentOS5 test VM

Root FS, only one partition

[root@kribbe tmp]# lvcreate -L10G -nXen_CentOS5_Test XenVG
 Logical volume "Xen_CentOS5_Test" created
root@kribbe tmp]# mkfs.ext3 /dev/XenVG/Xen_CentOS5_Test
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
1310720 inodes, 2621440 blocks
131072 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2684354560
80 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
       32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 28 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

SWAP

[root@kribbe tmp]# lvcreate -L1G -nXen_CentOS5_Test_swap XenVG
 Logical volume "Xen_CentOS5_Test_swap" created
[root@kribbe tmp]# mkswap /dev/XenVG/Xen_CentOS5_Test_swap
Setting up swapspace version 1, size = 1073737 kB

Virtualize Physical Nodes

On DOM_0 Create a lvm for the DOM_U
Mount this lvm on DOM_0
On Physical Node change runlevel to s
setup a exclude-list file, for details see eisxen
cd /; tar csp --exclude-from=/rootfs/exclude.lst /* |ssh DOM_0 "cd /<mounted LVM>; tar xsp"
change the fstab of the dom_u

Example exclude.lst, node specific, dont just copy, see also: eisxen
This list must not have an empty line at the end.
less /rootfs/exclude.lst
/boot
/data
/datastore
/datastore2
/proc
/rootfs
/etc/mtab

DOM_U is a centos-3.x

In order to run this as a virtual maschine, the dom_u might need a new version of e2fschk and module-init-tools. Therfore, on DOM_0 mount the DOM_U fs created in an earlier step, get e2fsprogs-1.39.tar.gz module-init-tools-3.2.tar.gz (or later) to this directory.

chroot to dom_u mountpoint
extract, compile, install e2fschk and module-init-tools

CentOS 5 with Virtualization package

Installed Version:

2.6.18-8.el5xen #1 SMP Thu Mar 15 19:56:43 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux

Run yum update, Version:

2.6.18-8.1.15.el5xen #1 SMP Mon Oct 22 09:01:12 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux

xen:

[root@kribbe ~]# xm dmesg
__  __            _____  ___   _____             ____       _ ____
\ \/ /___ _ __   |___ / / _ \ |___ /    _ __ ___| ___|  ___| | ___|
 \  // _ \ '_ \    |_ \| | | |  |_ \ __| '__/ __|___ \ / _ \ |___ \
 /  \  __/ | | |  ___) | |_| | ___) |__| | | (__ ___) |  __/ |___) |
/_/\_\___|_| |_| |____(_)___(_)____/   |_|  \___|____(_)___|_|____/

http://www.cl.cam.ac.uk/netos/xen
University of Cambridge Computer Laboratory

Xen version 3.0.3-rc5-8.1.15.el5 (mockbuild@) (gcc version 4.1.1 20070105 (Red Hat 4.1.1-52)) Mon Oct 22 08:25:42 EDT 2007
Latest ChangeSet: unavailable
....
(XEN) VMXON is done
(XEN) Dom0 has maximum 4 VCPUs

lvm2, bridge-utils

Installed Packages:
Name   : lvm2
Arch   : x86_64
Version: 2.02.16

Name   : bridge-utils
Arch   : x86_64
Version: 1.1

yum install vnc

use partition /dev/md3 mounted on /project for lvm

comment out ..... /project
umount /project
pvcreate /dev/md3
vgcreate XenVG /dev/md3
lvcreate -L10G -nXen_CentOS5_Test XenVG
mkfs.ext3 /dev/XenVG/Xen_CentOS5_Test
lvcreate -L1G -nXen_CentOS5_Test_swap XenVG
mkswap /dev/XenVG/Xen_CentOS5_Test_swap

Running various centOS Versions as VMs on kribbe

Check if virt-manager tools are working

virt-install can be used for VM installation.

CentOS 5 64-Bit in VM

set up kickstart file for VM, than

virt-install -p --location=http://www.dutchgrid.nl/mirror/centos/5/os/x86_64 --noautoconsole \
--file=/dev/XenVG/Xen_CentOS5_Test --name=domU001 --ram=1024  \
-x "ks=http://stal.nikhef.nl/ks/xen-test-koebrug.ks ip=194.171.97.11 \
netmask=255.255.255.0 dns=192.16.186.253 gateway=194.171.97.254"

Connect to th econsole of the starting vm:

xm list, lists the VMs:

[root@kribbe ~]# xm list
Name                                      ID Mem(MiB) VCPUs State   Time(s)
Domain-0                                   0     7025     4 r-----   1056.7
domU001                                    8     1023     1 -b----    490.8

xm console <ID> or <Name> of the VM (s.a.) creates a console of the VM

Worked

Note: no vnc option in the virt-install command,

--vnc option removed, does not boot.
during boot of the VM answer: q: graphics support: no

On VM:

koebrug.nikhef.nl

/etc/redhat-release
CentOS release 5 (Final)
[root@koebrug ~]# uname -a
Linux koebrug.nikhef.nl 2.6.18-8.el5xen #1 SMP Thu Mar 15 19:56:43 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux

CentOS 4.5 64-Bit in VM

silo.nikhef.nl

[root@silo ~]# uname -a Linux silo.nikhef.nl 2.6.9-55.ELxenU #1 SMP Wed May 2 14:29:26 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux [root@silo ~]# cat /etc/redhat-release CentOS release 4.5 (Final)

64 Bit DOM_U in 64 Bit DOM_0 seems to be no problem. 32Bit installations can not be done in this way, apropriate kernel needed Looking at virsh

Using VIRSH

Information on virsh can be found at: centos-wiki or Red Hat Virtualization

virsh is another virtualization management tool (built around the libvirt management API) which is now capable to deal with xen, future versions might also be able to manage kvm or qemu.

Since we plan to use xen we should stick with xm directly.

Virtual Maschine management with xm

based on: Chapter 17. Managing Virtual Machines Using xm

CentOS 5 i386-System -- Quattor generated

Problems

virt-manager not working centos-bug

Post-Quattor steps to prevent quattor from revoking installation/configuration operations.

on kribbe:
chkconfig cdp-listend off
chkconfig ncm-cdispd off

on stal:
[root@stal ~]# aii-shellfe --boot kribbe.nikhef.nl

to give back the control to quattor (fresh install next boot, will also switch on cdp-listen and ncm-cdispd)
[root@stal ~]#  aii-shellfe --install kribbe.nikhef.nl

Mount external storage for files that should survive a reboot/installation

mount -tnfs tbn15.nikhef.nl:/export/array2/local/tbadmin /tmpmnt

Hostname: kribbe.nikhef.nl
Kernel: 2.6.18-8.1.8.el5xen
HD-Layout:

[root@kribbe ~]# sfdisk -l /dev/sdb

Disk /dev/sdb: 60801 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

  Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sdb1   *      0+     32      33-    265041   fd  Linux raid autodetect
/dev/sdb2         33   51025   50993  409601272+  fd  Linux raid autodetect
/dev/sdb3      51026   58580    7555   60685537+  fd  Linux raid autodetect
/dev/sdb4      58581   60800    2220   17832150    5  Extended
/dev/sdb5      58581+  60147    1567-  12586896   fd  Linux raid autodetect
/dev/sdb6      60148+  60669     522-   4192933+  fd  Linux raid autodetect
/dev/sdb7      60670+  60800     131-   1052226   fd  Linux raid autodetect

====================

[root@kribbe ~]# cat /proc/mdstat 
Personalities : [raid1] 
md0 : active raid1 sdb1[1] sda1[0]
     264960 blocks [2/2] [UU]
     
md3 : active raid1 sdb2[1] sda2[0]
     409601152 blocks [2/2] [UU]
     
md5 : active raid1 sdb3[1] sda3[0]
     60685440 blocks [2/2] [UU]
      
md2 : active raid1 sdb6[1] sda6[0]
     4192832 blocks [2/2] [UU]
      
md4 : active raid1 sdb7[1] sda7[0]
     1052160 blocks [2/2] [UU]
      
md1 : active raid1 sdb5[1] sda5[0]
     12586816 blocks [2/2] [UU]
      
unused devices: <none>

Example installation of a CentOS5 VM

Create a VM in lvm partition

Setup lvm as stated above
Mount VM root fs: mount /dev/XenVG/Xen_CentOS5_Test /mnt
extract archive:
[root@kribbe tmp]# bunzip2 centos.5-0.20070424.img.tar.bz2
[root@kribbe tmp]# tar xvf centos.5-0.20070424.img.tar
loopmount image
[root@kribbe tmp]# mkdir /img
[root@kribbe tmp]# mount -o loop centos.5-0.img /img
cp image to logical volume
[root@kribbe img]# cp -a * /mnt/
Change Root PW in VM:

[root@kribbe mnt]# chroot /mnt
bash-3.1# pwconv
bash-3.1# passwd
Changing password for user root.

Set Hostname of VM: /etc/sysconfig/network

NETWORKING=yes
HOSTNAME=koebrug.nikhef.nl

no swap in VM: /etc/fstab

#/dev/sda2               none                    swap    sw       0 0

setup of VM start files

SELinux, Postinstallation steps

Cleaning up daemons, pay attention to ntp, do the dom_U has the correct time?

  /sbin/service microcode_ctl stop
  /sbin/chkconfig --del microcode_ctl
  /sbin/service smartd stop
  /sbin/chkconfig --del smartd
  /sbin/service ntpd stop
  /sbin/chkconfig --del ntpd

SELinux considerations: from SELinux in domU

If you are using SELinux, it is important to check that the image has the correct security context (xen_image_t), or access to the virtual disk will be denied to the domU system. You can check this with ls:

# ls -Z /srv/xen/mailserver.img 
-rw-r--r--  root root user_u:object_r:xen_image_t      /srv/xen/mailserver.img

If you are having trouble setting the right file context, please have a look at the Xen tips and tricks page. At any rate, turning off SELinux, as some howtos on this subject advise is a very poor workaround. Reading two manual pages (semanage(8) and restorecon(8)), for an extra layer of security is a good trade!

Xen Notes, Old Version, to be cleaned up

XenServer-3.2 Commercial Version

any information can be found on: xen-doku an related links.

Installation xenserver

Principle setup

VMs are organized in a Virtual Rack (a01-008-210)
Network: VLAN 1401 (10.97.210.0) and VLAN 158 (192.108.45.0) are configured
in VMs use xenbr1401(eth1401) for eth0 (internal network)
in VMs use xenbr1(eth1) for eth1 (external network)

Notes To install a new xenserver DOM_0

Local Disk is sdb
SAN is sda
If asked DONT CREATE A STORAGE REPOSITORY, this will delete ALL VMs in the SAN

Installation Procedure

Boot from xenserver CD
Set eth0 to ONBOOT=NO, i.e. don't use eth0 during installation
Configure eth1 with external IP (192.....)
NTP: 10.97.8.200
DNS: 10.97.1.192, 10.97.1.191, 141.52.8.18
NO XEN-STORAGE, disable FLAGS on sdb as well as on sda (SAN)
Use sdb (local disk) for installation of the base system
Post Installation:
1. add: /etc/sysconfig/static-routes: any net 10.0.0.0/9 gw 10.97.81
2. edit /etc/resolv.conf add search fzk.de, set 141 as primary nameserver
3. edit /boot/grub/menu.lst, replace hd1,0 with hd0,0
4. Manually setting the default Storage Repository Manually setting the default Storage Repository (SR)
  1. /etc/smtab: 7c2cbf8e-d22e-46a3-8b3c-7791499e7510 none lvm default auto
  2. service srmtab restart
  3. service xenagentd start
5. set up vlan:
  1. ifup eth0
  2. modprobe 8021q
  3. vconfig add eth0 1401
  4. vconfig add eth0 158
  5. Set up the following files accordingly

/etc/sysconfig/network-scripts

==== ifcfg-eth0 =====
DEVICE=eth0
ONBOOT=no
TYPE=Ethernet
HWADDR=00:1a:64:12:80:71
BRIDGE=xenbr0
LINKDELAY=5
check_link_down() { return 1 ; }
==== ifcfg-eth1 ==== 
DEVICE=eth1
BOOTPROTO=none
ONBOOT=yes
TYPE=Ethernet
HWADDR=00:1a:64:12:80:73
BRIDGE=xenbr1
LINKDELAY=5
check_link_down() { return 1 ; }
==== ifcfg-eth1401 ==== 
DEVICE=eth0.1401
ONBOOT=yes
TYPE=Ethernet
HWADDR=00:1a:64:12:80:71
BRIDGE=xenbr1401
LINKDELAY=5
VLAN=yes
check_link_down() { return 1 ; }
==== ifcfg-eth158 ==== 
DEVICE=eth0.158
ONBOOT=yes
TYPE=Ethernet
HWADDR=00:1a:64:12:80:71
BRIDGE=xenbr158
LINKDELAY=5
VLAN=yes
check_link_down() { return 1 ; }
==== ifcfg-xenbr0 ==== 
DEVICE=xenbr0
ONBOOT=no
TYPE=Bridge
DELAY=0
STP=off
check_link_down() { return 1 ; }
==== ifcfg-xenbr1 ==== 
DEVICE=xenbr1
ONBOOT=yes
TYPE=Bridge
DELAY=0
STP=off
NETMASK=255.255.255.0
IPADDR=192.108.45.86
GATEWAY=192.108.45.1
PEERDNS=yes
check_link_down() { return 1 ; }
==== ifcfg-xenbr1401 ==== 
DEVICE=xenbr1401
ONBOOT=yes
TYPE=Bridge
DELAY=0
STP=off
NETMASK=255.255.255.0
IPADDR=10.97.210.107
PEERDNS=yes
check_link_down() { return 1 ; }
==== ifcfg-xenbr158 ==== 
DEVICE=xenbr158
ONBOOT=yes
TYPE=Bridge
DELAY=0
STP=off
NETMASK=255.255.255.0
IPADDR=10.97.8.107
PEERDNS=yes
check_link_down() { return 1 ; }

Cluster LVM

cd /etc/yum.r*
wget http://ftp.halifax.rwth-aachen.de/centos/4/csgfs/CentOS-csgfs.repo
yum install lvm2-cluster

Debian / Xen3

Debian 4.0 / Xen3 - xen-linux-system-2.6.18-4-xen-amd64

Post Installation basic package:

apt-get install ssh xen-linux-system-2.6.18-4-xen-amd64 ntp ntp-server bridge-utils less

Needed XEN Scripts:

/etc/xen/xend-config.sxp

(logfile /var/log/xen/xend.log)
(loglevel DEBUG)
(network-script network-fzk.xen3)
(dom0-min-mem 196)
(dom0-cpus 0)

/etc/xen/scripts/network-fzk.xen3

#!/bin/sh
dir=$(dirname "$0")
echo "====== $dir ======"
"$dir/network-bridge" start vifnum=0 netdev=eth0
"$dir/network-bridge" start vifnum=1 netdev=eth1
echo "=== Bridges configured === "

Note: The last line is to make sure to have an CR after netdev=eth1, otherwise this line will not be executed

Configure 2 Bridges, but only internal nic has an IP

/etc/network/interfaces

auto lo
iface lo inet loopback

allow-hotplug eth0 eth1

iface eth1 inet manual

iface eth0 inet static
       address 10.97.4.150
       netmask 255.255.255.0
       network 10.97.4.0
       gateway 10.97.4.1
       broadcast 10.97.4.255
       # dns-* options are implemented by the resolvconf package, if installed
       dns-nameservers 10.97.1.191 141.52.8.18
       dns-search gridka.de fzk.de
       post-up route add -net 10.0.0.0/9 gw 10.97.4.1

OUTDATED Debian sarge amd64 / xen-3 nstallation

/etc/apt/sources.list

# Debian sources

deb http://amd64.debian.net/debian-amd64 sarge           main contrib non-free
deb http://security.debian.org           sarge/updates   main contrib non-free
deb http://www.backports.org/debian      sarge-backports main

deb-src http://amd64.debian.net/debian-amd64 sarge           main contrib non-free
deb-src http://www.backports.org/debian      sarge-backports main

deb http://ftp.uni-stuttgart.de/debian testing  main
deb http://ftp.uni-stuttgart.de/debian unstable main

deb http://packages.debianbase.de/sarge/amd64/xen3/ ./
deb-src http://packages.debianbase.de/sources/xen3 ./

/etc/apt/preferences

Package: *
Pin: release o=Debian,a=stable,l=Debian-Security
Pin-Priority: 950 

Package: *
Pin: release o=Debian,a=stable
Pin-Priority: 900

Package: *
Pin: release o=Backports.org archive,a=sarge-backports
Pin-Priority: 800

Package: *
Pin: release o=Debian,a=testing
Pin-Priority: 700

Package: *
Pin: release o=Debian,a=unstable
Pin-Priority: 600

Package: *
Pin: origin ""
Pin-Priority: 400

/boot/grub/menu.lst

title           Xen 3.0.3-1-amd64 / Debian GNU/Linux, kernel 2.6.18-2-xen-amd64
root            (hd0,0)
kernel          /boot/xen-3.0.3-1-amd64.gz
module          /boot/vmlinuz-2.6.18-2-xen-amd64 root=/dev/sda1 ro console=tty0 console=tty0 max_loop=64
module          /boot/initrd.img-2.6.18-2-xen-amd64
savedefault

Install xen

apt-cache search xen-linux-system-2.6

apt-get install xen-linux-system-2.6.18-2-xen-amd64
apt-get install bridge-utils

Make sure to have brctl installed

apt-get install bridge-utils
/etc/init.d/xend resart

ifconfig should show the bridges xenbr0/1

Scripts for dual homed network

/etc/xen/scripts/network-fzk.xen3

#!/bin/sh
dir=$(dirname "$0")
echo "====== $dir ======"
"$dir/network-bridge" start vifnum=0 netdev=eth0
"$dir/network-bridge" start vifnum=1 netdev=eth1

patch /etc/xen/xend-config.sxp

--- /etc/xen/xend-config.sxp.orig      :58:47.000000000 +0100
+++ /etc/xen/xend-config.sxp   :11:42.000000000 +0100
@@ -11,8 +11,8 @@
# Commented out entries show the default for that entry, unless otherwise
# specified.

-#(logfile /var/log/xen/xend.log)
-#(loglevel DEBUG)
+(logfile /var/log/xen/xend.log)
+(loglevel DEBUG)
 
#(xend-http-server no)
#(xend-unix-server no)
@@ -84,8 +84,8 @@
# two fake interfaces per guest domain.  To do things like this, write
# yourself a wrapper script, and call network-bridge from it, as appropriate.
#
-(network-script network-dummy)
-
+#(network-script network-dummy)
+(network-script network-fzk.xen3)
# The script used to control virtual interfaces.  This can be overridden on a
# per-vif basis when creating a domain or a configuring a new vif.  The
# vif-bridge script is designed for use with the network-bridge script, or
@@ -99,7 +99,7 @@
# If you are using only one bridge, the vif-bridge script will discover that,
# so there is no need to specify it explicitly.
#
-(vif-script vif-bridge)
+#(vif-script vif-bridge)


## Use the following if network traffic is routed, as an alternative to the

Creating an SL4-Image

Install SL4 somewhere, use minimal setup
create exclude.list (/proc, /sys, /rootfs, /..
tar cvfpz /

On xen3 dom_0

a01-004-151:~# lvcreate -L1G -nXen_SL4_raw XenVG
 Logical volume "Xen_SL4_raw" created
a01-004-151:~# lvcreate -L1G -nXen_SL4_Dirs XenVG
 Logical volume "Xen_SL4_Dirs" created
a01-004-151:~# lvcreate -L1G -nXen_SL4_swap XenVG
 Logical volume "Xen_SL4_swap" created
a01-004-151:~# mkswap /dev/XenVG/Xen_SL4_swap 
Setting up swapspace version 1, size = kB
no label, UUID=377313c6-498b-4525-b0d3-f9d9fb2c46bd

a01-004-151:~# mkfs.ext3 /dev/XenVG/Xen_SL4_raw  

a01-004-151:~# mkfs.ext3 /dev/XenVG/Xen_SL4_Dirs

Create Image

SL3 image

module_init_tools

SL4 image

out of the box ?

Debian/Xen2 - outdated

OS-Installation

Ganglia on debian

To install and configure ganglia on the dom0 do:

* apt-get install ganglia-monitor
* scp ce-fzk:/opt/glite/yaim/rpms/gmond.conf /etc/
* /etc/init.d/ganglia-monitor restart

New xen-Kernels

To compile new dom-U kernels, cd to xen/linux-*-xenU and do

make menuconfig ....choose your options
make ARCH=xen dep bzImage modules modules_install

Debian -- XEN

*Boot from Debian 3.1r1 CD
*Configure first network interface with the external IP (nameserver e.g. 141.52.8.18)
*Partitioning: Whole disc in 2 partitions (50 GB / ; rest /srv (for using lvm see below)
*Installation Type: Manual selection
*additional packages: run script install_packages.sh

As the debian default installation is quite small addidional packages are needed, the following script should get them:

#!/bin/bash
apt-get install -y make
apt-get install -y gcc
apt-get install -y subversion
apt-get install -y bridge-utils
apt-get install -y curl
apt-get install -y libcurl3-dev
apt-get install -y zlib1g-dev
apt-get install -y zlib1g
apt-get install -y python-dev
apt-get install -y python-twisted
apt-get install -y bzip2
apt-get install -y linuxdoc-tools-latex
apt-get install -y gs-common
apt-get install -y transfig
apt-get install -y host
apt-get install -y iptables-dev
apt-get install -y ntpdate
apt-get install -y module-init-tools
apt-get install -y iproute
apt-get install -y lvm2
apt-get install -y dmsetup
mkdir /opt/xen
cd /opt/xen
wget http://www.cl.cam.ac.uk/Research/SRG/netos/xen/downloads/xen-2.0.7-src.tgz
tar xvfz xen-2.0.7-src.tgz
cd xen-2.0
exit

Untill I find some time or somebody else puts the following in a sed line do: edit Makefile, change the line: Kernels ?= ... so that the 2.4 Kernels are also build, i.e.

KERNELS ?= linux-2.6-xen0 linux-2.6-xenU linux-2.4-xen0 linux-2.4-xenU

Then build the xen-kernels:

make world
make install

Setup /boot/grub/menu.lst

Configure this file to boot the xen kernel and to set the max_loop Device parameter. Change below the line

## ## End Default Options ##

Example:

#### XEN ####
title Xen 2.0 / XenLinux 2.6
root   (hd0,0)
kernel /boot/xen-2.0.gz dom0_mem=64000 console=vga
module /boot/vmlinuz-2.6-xen0 root=/dev/sda1 ro console=tty0 max_loop=64
boot

Configure Network

The network is centraly configured in /etc/network/interfaces .

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
       address 192.108.45.66
       netmask 255.255.255.0
       network 192.108.45.0
       broadcast 192.108.45.255
       gateway 192.108.45.1
      # dns-* options are implemented by the resolvconf package, if installed
       dns-nameservers 10.97.1.191 141.52.8.18

Configure secound nic

edit /etc/network/interfaces

add eth1 in the line auto eth0
add a secound interface block like:

iface eth1 inet static
       address 10.97.4.130
       netmask 255.255.255.0
       network 10.97.4.0
       broadcast 10.97.4.255
       #gateway 10.97.4.1
       # dns-* options are implemented by the resolvconf package, if installed
       dns-nameservers 10.97.1.191 141.52.8.18
       dns-search gridka.de fzk.de

Add a route

append to the interfaces file a line like:

post-up route add -net 10.0.0.0/9 gw 10.97.4.1

to add a route

Make sure to have enough loop devices

for minor in `seq 8 1 63` ; do mknod /dev/loop$minor b 7 $minor ; done

==== LVM Logical Volume Manager ====

Make sure that lvm2 and dmsetup are installed.

Create physical volume: 
*pvcreate /dev/sdb1
here we use the sec har disc with one partition, any other setup is possible.
All partitions can be used for a physical volume, from these a Volume Group is created
*vgcreate XenVG /dev/sdb1 /dev/<and all other pv created before>
In this VolumeGroup create the logical volumes to be used in the images, for example
*lvcreate -L20G -nXen_g_CE_home XenVG
To get a list of available logical volumes:
*lvscan -v

Note Take care to set the permissions of the lv apropriatly in the virtual servers, e.g. chmod 1777 /tmp for imported tmp directories in the virtual servers.

Images in lvm

Create a suitable lvm volume with ext3 fs:

lvcreate -L4GB -n Xen_SE_DC_Sys XenVG
mkfs.ext3 /dev/XenVG/Xen_SE_DC_Sys

XEN POSTINSTALLATION STEPS -- CONFIGURATION of automatic domain start

The files which are needed to start the images (xm create <image-start-file>) should be available through nfs.

This procedure is slightly different from default configuration, as we want to have multiple nics configured in the virtual servers. Procedure on client:

NFS:

add to /etc/fstab

a01-004-155:/nfs/etc_xen /etc/xen_nfs nfs ro 0 0

command: mount -a

Create xen-autostart structure

* mv /etc/xen /etc/xen.local
* mkdir -p /etc/xen/auto
* mkdir /etc/xen_nfs
* ln -s /etc/xen_nfs/scripts /etc/xen/scripts
* ln -s /etc/xen_nfs/auto /etc/xen/auto/<IMAGES TO START ON HOST>
* ln -s /etc/xen_nfs/xend-config.sxp /etc/xen/xend-config.sxp
* ln -s /etc/init.d/xendomains /etc/rc2.d/S91xendomains
* ln -s /etc/init.d/xend /etc/rc2.d/S90xend

Timeservers

Virtual servers are using the time of the xen host, make sure that ntpdate is running and is configured coeectly, i.e. use 10.97.4.200 in /etc/default/ntpdate. Make sure that the time is upated in a cron job:

crontab -e
58 */6 * * * /usr/sbin/ntpdate 10.97.4.200 > /tmp/zeit.log
/etc/init.d/cron restart

Activating Second Network Interface

To activate the second network interface the following procedure was applied:

http://wiki.xensource.com/xenwiki/XenNetworking

if you want to use multiple bridges, you must create them yourself, either manually, or via your own startup script, or via a custom script to replace network-bridge. For example: The second network interface is started in dom_0 with the script /root/xen-net-init:

#!/bin/bash
# A.G.
if [ $# != 3 ] ; then
       echo -e "Usage: $0 <DOMAIN-NUMBER> <Internal IP> <External IP>\n"
       exit 1
fi
XEN_S=/etc/xen/scripts
D=$1
# Test if the domain number given really exists
xm list | tail -n +2 | awk '{print $2}' | grep -q $D
if [ $? == 1 ] ; then
       echo -e "Domain $D does not exist! Please provide a DOMAIN-NUMBER\n"
       exit 2 
fi
$XEN_S/network start bridge=xen-br0 netdev=eth0 antispoof=no
$XEN_S/network start bridge=xen-br1 netdev=eth1 antispoof=no
$XEN_S/vif-bridge up domain=${D} vif=vif${D}.0 bridge=xen-br0 mac="FE:FF:FF:FF:FF:FF" ip="$2"
$XEN_S/vif-bridge up domain=${D} vif=vif${D}.1 bridge=xen-br1 mac="FE:FF:FF:FF:FF:FF" ip="$3"

Xen Dom_U Start Configuration Files for the Virtual Maschines

Create in /etc/xen/auto/ the configuration files for each virtual maschine to run on the host. The auto directory will be evaluated at dom_0 boot time. Example /etc/xen/auto/pps-bdii-fzk:

#  -*- mode: python; -*-

name = "pps-bdii-fzk"
vmid = 1

kernel = "/boot/vmlinuz-2.4.30-xenU"
memory = 256
cpu = 1

# Number of network interfaces. Default is 1.
nics=2
vif=[ 'mac=00:16:3e:70:%d:01,bridge=br0' % vmid,'mac=00:16:3e:70:%d:02,bridge=br1' % vmid]

disk = [ 'file:/data/xen-%s,hda1,w' % name,
         'file:/data/swap-%d,hda2,w' % vmid]

root = "/dev/hda1 ro"

Note: To avoid collisions of mac addresses it is better use constructions like:

vif=[ 'mac=00:16:3e:70:Hex1:Hex2,bridge=br0','mac=00:16:3e:70:Hex3:Hex4,bridge=br1']

Where Hex 1-4 are the last 2 tuples of the internal and external IP

Note: If you want use lvm partitions from dom_0 you can use:

disk = [ 'file:/data/xen-%s,hda1,w' % name,
         'file:/data/swap-%d,hda2,w' % vmid,
         'phy:/dev/XenVG/XenCE_home,hdb1,w',
         'phy:/dev/XenVG/XenCE_tmp,hdb2,w']

hdb1/2 is then to included in the fstab file in the virt. maschine, for example:

/dev/hdb1               /home                   ext3    defaults        1 1
/dev/hdb2               /tmp                    ext3    defaults        1 1

Note: Before /dev/hdb1/2 can be used in the virtual maschine a filesystem has to be created there. Therefore the following can be done:

comment out /dev/hdb lines in /ets/fstab in the image
boot the virtual maschine
xm console to this <ID>
mkfs.ext3 /dev/hdb1
mkfs.ext3 /dev/hdb2
uncomment the lines in /etc/fstab

Images for the virtual maschines

A basic ~2GB image can be optained with:

dd if=/dev/zero of=/<Image-Name> bs=512 count=4000000
mkfs.ext3 <Image-Name>
mount -o loop <Image-file> /mnt

from an existing linux system which is to be virtualized do

cd /;tar <all dirs except nfs mounted files>, proc|ssh <where created image is mounted> "cd /mnt; tar xsp"

wget http://savannah.fzk.de/websites/fzk/gridkaschool/2005/xen-images/sl-3.0.5.img.ready-to-yaim--reloaded.gz
wget http://savannah.fzk.de/websites/fzk/gridkaschool/2005/xen-images/swap-1.gz

Unzip the image and the swap file, and move them to /data/<Virt-hostname-Name>. Virt-Node-Name can be e.g. pps-bdii-fzk. For each Virtual host one image and swap file has to be created with the name used in the /etc/xen/auto/<start-config-file>. Before this image can be used several changes in network configuration files have to be done, Therefore loop mount the image and adapt the files

Changing the network configurationof the images

To manipulate files within the image it has to be mounted:

mount -o loop /<PATH_TO>/<IMAGE_NAME> /tmp

adapt the following files:

/etc/ssh/ssh* to use Port 24
/etc/apt/apt.conf Default a proxy is used if not needed change apt.conf to:

// User customizable configuration

RPM
{
 // Uncomment to disable GPG-signature checking for packages
 // GPG-Check "false";
};

// Options for the downloading routines
Acquire
{
  // Retries "1";
  // http::Proxy "http://user:password@proxy-server.domain.tld:port/";
  //http::Proxy "http://proxy.fzk.de:8000/";
  //ftp::Proxy "http://proxy.fzk.de:8000/";
};

/etc/fstab remove the nfs line gks..., otherwise the booting will take till the nfs mount timeouts, i.e. ages, I'll create a new image soon.
/etc/sysconfig/network-scripts/route-eth0/1: set the default route of the internal networ
/etc/sysconfig/network-scripts/ifcfg-eth0/1}

Configure the network interfaces according to which bridge it is bound. In the examples below it is assumed that the virtual hosts are running in the admin rack 4

ifcfg-eth0:

DEVICE=eth0
BOOTPROTO=static
ONBOOT=yes
IPADDR=192.108.45.XYZ
NETMASK=255.255.255.0
GATEWAY=192.108.45.1
TYPE=Ethernet

ifcfg-eth1:

DEVICE=eth1
BOOTPROTO=static
ONBOOT=yes
IPADDR=10.97.4.ABC
NETMASK=255.255.255.0
TYPE=Ethernet

Resizing of a image

To increase an Image one can use.

dd if=/dev/zero bs=512  count=20000000 >> <IMAGE>

This will add 10 GB to the image

Next the filesystem has to be checked:

e2fsck -f xen-pps-ce-fzk_torque_14G

and resized

resize2fs xen-pps-ce-fzk_torque_14G

Converting a physical server in a virtual

create image file
on server: cd /; tar csp <all without home, tmp, nfs-dirs> | ssh virt. server:/virt-server-image-file "cat - tar xsp"
set values in the network config files (eth0/1, fstab, ..) in the virt. server accordingly

Starting the Virtual Maschines

For the first time the following steps have to performed manualy, they can be included in the boot procedure.

The following commands have to be executed:

/etc/init.d/xend start
xm create /etc/xen/auto/<Virt. Maschine Name> to be started
/root/xen-net-init <ID> <IP 1> <IP 2>

The <ID> can be evaluated with xm list. IP 1 and IP 2 have to set according to where eth0 and eth1 are bound to (internal 10.X.X.X, or external 192.X.X.X network)

Now the virtual maschine should be ssh-accessable from your desktop, if not you can login to the dom_0 host and start a virtual-host-console there with: xm create <ID>. Now correct the network configuration of the virtual host.

Configuration of the virtual hosts

Network configuration

Updating the base OS

To update the base OS (Scientific Linux Cern 3.0.X) to the actual version do:

check proxy settings (see above)
check /etc/hosts for not needed entries
check the repository settings in /etc/apt/sources.list
apt-get update
apt-get upgrade

Problems

On nfs Client:

[root@bdii-fzk root]# mount -a

gives:

mount: RPC: Program not registered

Is the nfsserver running correctly, is the nfsd module loaded (modprobe nfsd), possible problem: wrong modules, have to be the same as the kernel was compiled for. Can hapen when you just cp the kernels.

Is the nfs mount line in /etc/fstab correct?

xm create doesnt work

check if module-init-tools is installed

network bridges cant be created

Network package iproute not installed, causes that the start of the xend creates a not usable routing table, i.e. route cannot be setup through bridge, just do apt-get install iproute.

Virtual server with lvm in fstab doesnt start

at first boot/mount of the lvm devices a filesystem has to be created on the mounted devices, starting a console gives:

xm console <ID>

Checking all file systems. [/sbin/fsck.ext3 (1) -- /home] fsck.ext3 -a /dev/hdb1 [/sbin/fsck.ext3 (1) -- /tmp] fsck.ext3 -a /dev/hdb2 fsck.ext3: Bad magic number in super-block while trying to open /dev/hdb2 [FAILED]

- - An error occurred during the file system check.
  - Dropping you to a shell; the system will reboot
  - when you leave the shell.

Give root password for maintenance

This can happen if you have in the xm create start file you have something like:

'phy:/dev/XenVG/Xen_l_CE_home,hdb1,w',

in the fstab of the virtual maschine you have something like
/dev/hdb1 /home

then give root passwort and create the filesystems with e.g.

mkfs.ext3 /dev/hdb1

MySQL

Aus meinen Notizen, ohne weitere Formatierung.

Passwort fuer einen Benutzer einer Datenbank aendern:
1) als root einloggen:
 mysql -h localhost -u root -p

 2) setzen des Passworts fuer den Benutzer ->accounting<- auf das Passwort 
->accountingspw<-:
 
 mysql> set password for accounting@localhost=Password('accountingspw');

 USE mysql
GRANT SELECT, INSERT, UPDATE, DELETE ON accounting.* TO 'accounting' 
IDENTIFIED BY 'accounting';
DELETE FROM user WHERE user LIKE 'accounting';
DELETE FROM db WHERE user LIKE 'accounting';
INSERT INTO user (host,user,password,create_priv,drop_priv) VALUES 
('localhost','accounting',password('accounting'),'Y','Y');
INSERT INTO user (host,user,password,create_priv,drop_priv) VALUES 
('127.0.0.1','accounting',password('accounting'),'Y','Y');
INSERT INTO user (host,user,password,create_priv,drop_priv) VALUES 
('localhost.localdomain','accounting',password('accounting'),'Y','Y');
INSERT INTO user (host,user,password,create_priv,drop_priv) VALUES 
('a01-004-123.gridka.de','accounting',password('accounting'),'Y','Y');
INSERT INTO user (host,user,password,create_priv, drop_priv) VALUES 
('lcg-gridka-ce','accounting',password('accounting'),'Y','Y');
INSERT INTO db 
(host,db,user,select_priv,insert_priv,update_priv,delete_priv,create_priv, 
alter_priv) VALUES ('%','accounting','accounting','Y','Y','Y','Y','Y','Y');
FLUSH PRIVILEGES;
DROP DATABASE IF EXISTS accounting;
CREATE DATABASE accounting;
USE accounting;

==== Um von meinem Rechner darauf zu arbeiten =====

[root@lcg-gridka-ce yaim]# mysql -h localhost -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4 to server version: 4.0.25-standard

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> USE mysql Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A

Database changed mysql> INSERT INTO user (host,user,password,create_priv, drop_priv) VALUES

   -> ('iwrgabriel.ka.fzk.de','accounting',password('accounting'),'Y','Y');

Query OK, 1 row affected (0.10 sec)

mysql> FLUSH PRIVILEGES; Query OK, 0 rows affected (0.02 sec)

mysql> quit Bye

Xen on CentOS 5 - Notes

Docu on CentOS

CentOS 5

CentOS 5 X86_64, Minimal system

Additional Packages

Post Install, get the following packages

xen 3.1.2-rc from mercurial

LVM 2

Setting up LVM2 on kribbe

Example: lvm for a CentOS5 test VM

Virtualize Physical Nodes

DOM_U is a centos-3.x

CentOS 5 with Virtualization package

Running various centOS Versions as VMs on kribbe

Check if virt-manager tools are working

CentOS 5 64-Bit in VM

CentOS 4.5 64-Bit in VM

Using VIRSH

Virtual Maschine management with xm

CentOS 5 i386-System -- Quattor generated

Problems

Example installation of a CentOS5 VM

SELinux, Postinstallation steps

Xen Notes, Old Version, to be cleaned up

XenServer-3.2 Commercial Version

Installation xenserver

Principle setup

Installation Procedure

Cluster LVM

Debian / Xen3

Debian 4.0 / Xen3 - xen-linux-system-2.6.18-4-xen-amd64

Configure 2 Bridges, but only internal nic has an IP

OUTDATED Debian sarge amd64 / xen-3 nstallation

Install xen

Make sure to have brctl installed

Scripts for dual homed network

Creating an SL4-Image

On xen3 dom_0

Create Image

SL3 image

SL4 image

Debian/Xen2 - outdated

OS-Installation

Ganglia on debian

New xen-Kernels

Debian -- XEN

Setup /boot/grub/menu.lst

Configure Network

Configure secound nic

Add a route

Make sure to have enough loop devices

==== LVM Logical Volume Manager ====

Images in lvm

XEN POSTINSTALLATION STEPS -- CONFIGURATION of automatic domain start

The files which are needed to start the images (xm create <image-start-file>) should be available through nfs.

Timeservers

Activating Second Network Interface

Xen Dom_U Start Configuration Files for the Virtual Maschines

Images for the virtual maschines

Changing the network configurationof the images

Resizing of a image

Converting a physical server in a virtual

Starting the Virtual Maschines

Configuration of the virtual hosts

Network configuration

Updating the base OS

Problems

On nfs Client:

xm create doesnt work

network bridges cant be created

Virtual server with lvm in fstab doesnt start

MySQL

==== Um von meinem Rechner darauf zu arbeiten =====

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