XenServer: Initial Deployment thoughts

I thought I would jot down some thoughts I have had on XenServer after really digging deep into it at a client site with the Citrix Engineers.

The product is VERY command line based.  Many of the functions and features I take for granted in the VMware interface are buried in Xen’s Linux command line interface.  Simple procedures in VMware translate to multiline commands in Xen.  Although intimidating at first, with practice, clients will be awe struck watching me configure the XenServer from the Command Line Interface. ?

At this time, XenServer has some limitations when it comes to networking.  Currently XenServer only supports network bonding of 2 NICs at a time and only in an active passive mode.  This translates to forcing all of your Virtual Machine network traffic over 1 NIC card.  With VMware I routinely bond 4 – 6 NICs together to accommodate Virtual Machine traffic and they are all active at once.  To get around this issue, you can manually create different bonds and manually assign your VMs to them to distribute the load a bit.

This same networking issue also exists on the storage side if using NFS or ISCSI.  All Storage traffic must be forced over 1 active NIC bond at a time.

When I needed to bond 2 NICs for Management redundancy, I had to do this operation in the Linux operating system essentially ‘hiding’ the configuration from XenServer. You set the XenServer to ‘Forget’ the NICs and then bond them in Linux.

Many of the initial issues with XenServer 4.1 are being addressed in the upcoming 4.2 release and will hopefully be ironed out.