Xen on CentOS 5 - Notes

System -- Quattor generated

• 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>

Added to Quattor System

xen 3.1

wget http://bits.xensource.com/oss-xen/release/3.1.0/kernel-3.1-rhel5x/RPMS/i386/xen-3.1.0-1.i386.rpm
wget http://bits.xensource.com/oss-xen/release/3.1.0/kernel-3.1-rhel5x/RPMS/i386/kernel-xen-2.6.18-3.1.0.i386.rpm
wget http://bits.xensource.com/oss-xen/release/3.1.0/kernel-3.1-rhel5x/RPMS/i386/xen-devel-3.1.0-1.i386.rpm
wget http://bits.xensource.com/oss-xen/release/3.1.0/kernel-3.1-rhel5x/SRPMS/xen-3.1.0-1.src.rpm

Notes:

1. rpm -Uvh kernel-xen-2.6.18-3.1.0.i386.rpm (is in older version than installed one, kept the installed one)
2. rpm -Uvh xen-3.1.0-1.i386.rpm
3. sources and dev package not installed

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