Ubuntu 11.04 on Citrix XenServer 5.5, Part 3

This is part 3 of a series on installing Ubuntu 11.04 (Natty Narwhal) on Citrix XenServer 5.5 in paravirtualization (PV) mode. [Part 1] [Part 2]

In most cases you are virtualizing servers with XenServer, and I highly recommend a manual partition layout.  User interaction with servers is unpredictable, and you do not want to fill the root (/) filesystem making it unusable.  Also, servers can benefit (features, performance, security, etc.) from using different filesystems and types depending on the location and use of files.  

General guidelines for servers:

• /boot should be a separate partition.  I always make it the first, primary partition.  If you have problems booting, it is easy to remember which partition it is.  256 MB is a good, sufficient size for boot.  Use ext3 because it is a stable, well-supported journaling filesystem. ext4 or others may not be supported by the bootloader, and your system will fail to boot.  (Note: XenServer does not support booting from ext4!)
• / or "root" should be a separate, primary partition.  I recommend at least 8 GB.
• /tmp should be separate as users and applications write to this location and you want to avoid it filling /.  I recommend at least 4 GB, but can be bigger if known applications write large amounts of temporary data.
• swap should be separate.  An old rule of thumb is "swap should be double the amount of RAM"; however, I don't believe it is applicable on modern day systems.   1) I have not seen a Linux server swap  more than 512 MB, and 2) you have bigger problems if you're using more swap than RAM.   See  https://help.ubuntu.com/community/Partitioning/Swap for more information.
• Use the rest of the disk for /var.  /home is also good idea if you have untrusted, interactive users.  I tend to keep large

I use the XFS file system. I prefer it over other journaling filesystems, well, because I've been using it for close to 10 years.  From my personal laptop to large web and database servers it has never (knock on wood) done me wrong!  This includes power failure during use (power brown/black-outs, and people accidentally yanking the power cord from a workstation)  It is stable, feature-rich, scales, and performs well in most applications.   I used and seen most others and have had integrity and stability problems with a number of them.

Why not Logical Volume Management (LVM) you ask? I like KISS, and have never really found a need for introducing an extra layer to use its features.  I'm typically upgrading hardware before resizing partitions.

My typical partition layout:

Size    Mount Point     Filesystem      Partition Type
----    -----------     ----------      --------------
512 MB  /boot           ext3            primary
8 GB    /               xfs             primary
4 GB    /tmp            xfs             extended
4 GB    -               swap            extended
rest    /var            xfs             primary