Difference between revisions of "Xen on CentOS - Automating Installation-Administration"
(10 intermediate revisions by the same user not shown) | |||
Line 4: | Line 4: | ||
== Needed Tools == | == Needed Tools == | ||
* Quattor [[http://www.nikhef.nl/pub/projects/grid/gridwiki/index.php/NDPF#Grid.2C_Quattor_and_Yaim Quattor at nikhef]] | * Quattor [[http://www.nikhef.nl/pub/projects/grid/gridwiki/index.php/NDPF#Grid.2C_Quattor_and_Yaim Quattor at nikhef]] | ||
− | * [https://www.cs.tcd.ie/Stephen.Childs/pypxeboot/ pypxeboot] | + | * [https://www.cs.tcd.ie/Stephen.Childs/pypxeboot/ pypxeboot] (on dom0s) |
+ | |||
+ | == Quattor related notes == | ||
+ | === filesystem dom0 === | ||
+ | |||
+ | Quattor templates: | ||
+ | /cfg/sites/ndpf/site/filesystems/*.tpl | ||
+ | |||
+ | !!! IMPORTANT: !!! | ||
+ | * foresee a logvol with mount point /var/lib/xen/save which will take "Speicherabbilder" of running | ||
+ | domUs, when the dom0 gets the reboot command, therefore it should be | ||
+ | as large as available RAM + something (summ of all swap of domUs ?, see below) | ||
+ | * give each domU not more than 512MB swap, if a domU excessively uses swap it will anyways got stuck. | ||
+ | |||
+ | == Naming convention: == | ||
+ | since the Filesystem layout depends on the hardware [how many hard disks 2-4, which raid (1 or 1-0)] and on the function in terms of xen-Dom0, xen-DomU, generic, ... | ||
+ | I used the following scheme <hardware>-<function>.tpl | ||
+ | The filesystem Template for our Dell-Power-Edge-1950 -function xen-Dom0 would then be: pe1950-x0.tpl | ||
+ | |||
+ | = Virtualization considerations = | ||
+ | |||
+ | == dom0 Filesystem layout == | ||
+ | * Dom0 (Host) needs < 10G for its system, tmp is not extensively used nor is var. To prevent the system to be unresponsive due to full / fs we could give 4GB /tmp and /var each and an extra volume for /var/lib/xen/save (size .gt. pys. RAM in dom0) to take the files in which the state of the domUs are saved (roughly comparable to hybernate a running computer). These values can be smaller if we have hardware which has some disk space restrictions. | ||
+ | |||
+ | |||
+ | * For performance its best to limit the Memory of the dom0 to 512 MB and to prevent it from ballooning (i.e. takes all available memory) | ||
+ | |||
+ | * Dom0-swap should never happen, there are no processes that consume memory, if it swaps something went wrong, just in case we can try 1 GB swap | ||
+ | |||
+ | === PE-1950 configuration === | ||
+ | Hard disks: 2 X 500GB | ||
+ | principle layout: | ||
+ | * Raid-1 | ||
+ | |||
+ | * Primary Partitions | ||
+ | /boot 512MB | ||
+ | /swap 4096MB | ||
+ | |||
+ | * LVM | ||
+ | Volumegroup System, Size: rest of available space | ||
+ | I System-Volumes-Dom0 [/, /tmp, /var /var/lib/xen/save] fs: ext3 | ||
+ | II DomU-lvms added when needed | ||
+ | |||
+ | === PE-2950 configuration === | ||
+ | Hard disks: 4 X 500GB | ||
+ | principle layout:hardware raid-10 | ||
+ | |||
+ | |||
+ | * Primary Partitions | ||
+ | /boot 512MB | ||
+ | /swap 4096MB | ||
+ | |||
+ | * LVM | ||
+ | Volumegroups systemvg and xenvg, Size: rest of available space | ||
+ | * System-Volumes-Dom0 [/, /tmp, /var, /var/lib/xen/save] fs: ext3 | ||
+ | * DomU-lvms added when needed | ||
+ | |||
+ | == Network == | ||
+ | === DomU MAC Adresses === | ||
+ | Xen domUs have the MAC-Addresses in 00:16:3e:*:*:*. | ||
+ | To avoid collisions in MAC adresses one can take the IP of the domU A.B.C.D and use the hex values for B,C and D. The following command might be usefull: | ||
+ | printf "00:16:3e:%02x:%02x:%02x\n" {B,C,D} | ||
+ | replace B,C,D accordingly. |
Latest revision as of 10:38, 23 March 2009
UNDER CONSTRUCTION
Introduction
This document assumes an functioning quattor environment and an installationserver with dhcp, tftp, and pxeboot.
Needed Tools
- Quattor [Quattor at nikhef]
- pypxeboot (on dom0s)
filesystem dom0
Quattor templates: /cfg/sites/ndpf/site/filesystems/*.tpl
!!! IMPORTANT: !!! * foresee a logvol with mount point /var/lib/xen/save which will take "Speicherabbilder" of running domUs, when the dom0 gets the reboot command, therefore it should be as large as available RAM + something (summ of all swap of domUs ?, see below) * give each domU not more than 512MB swap, if a domU excessively uses swap it will anyways got stuck.
Naming convention:
since the Filesystem layout depends on the hardware [how many hard disks 2-4, which raid (1 or 1-0)] and on the function in terms of xen-Dom0, xen-DomU, generic, ... I used the following scheme <hardware>-<function>.tpl The filesystem Template for our Dell-Power-Edge-1950 -function xen-Dom0 would then be: pe1950-x0.tpl
Virtualization considerations
dom0 Filesystem layout
- Dom0 (Host) needs < 10G for its system, tmp is not extensively used nor is var. To prevent the system to be unresponsive due to full / fs we could give 4GB /tmp and /var each and an extra volume for /var/lib/xen/save (size .gt. pys. RAM in dom0) to take the files in which the state of the domUs are saved (roughly comparable to hybernate a running computer). These values can be smaller if we have hardware which has some disk space restrictions.
- For performance its best to limit the Memory of the dom0 to 512 MB and to prevent it from ballooning (i.e. takes all available memory)
- Dom0-swap should never happen, there are no processes that consume memory, if it swaps something went wrong, just in case we can try 1 GB swap
PE-1950 configuration
Hard disks: 2 X 500GB principle layout:
- Raid-1
- Primary Partitions
/boot 512MB /swap 4096MB
- LVM
Volumegroup System, Size: rest of available space I System-Volumes-Dom0 [/, /tmp, /var /var/lib/xen/save] fs: ext3 II DomU-lvms added when needed
PE-2950 configuration
Hard disks: 4 X 500GB principle layout:hardware raid-10
- Primary Partitions
/boot 512MB /swap 4096MB
- LVM
Volumegroups systemvg and xenvg, Size: rest of available space
- System-Volumes-Dom0 [/, /tmp, /var, /var/lib/xen/save] fs: ext3
- DomU-lvms added when needed
Network
DomU MAC Adresses
Xen domUs have the MAC-Addresses in 00:16:3e:*:*:*. To avoid collisions in MAC adresses one can take the IP of the domU A.B.C.D and use the hex values for B,C and D. The following command might be usefull:
printf "00:16:3e:%02x:%02x:%02x\n" {B,C,D}
replace B,C,D accordingly.