Somewhere out there!

I spent much of yesterday trying to get a XGT for Ubuntu Feisty working. What a PITA!

A discussion and tips on optimising VMWare Server on NFS & RedHat Cluster Suite. Similar methods will be useful for XenEnterprise v4.

I’ve been meaning to put a few notes together of some work on Ubuntu XGT templates for XenEnterprise I did in June, but XE v4 supposely has a new system so I’ll have to check that out first. I did note this blog entry a few days ago and decided to put a tip bits of my own up.

The OSS version Xen is more tightly integrated with the host operating system and disk device node directly from the host to Linux guests. So /dev/sdb1 in the host could be /dev/sda1 in the guest. XenEnterprise acts more like Vmware and passes LVM blocks though to the guests as disks. Just like Vmware this makes it a much trickier in XE to resize or act directly on a mount file system from the host.

If the guest is shutdown the best method for accessing the filesystem is to use kpartx or lomount combined with losetup.

First find the details:

I did a quick test install of Windows 2008 Standard Server Beta2 onto my XenEnterprise server. Requires the PV drivers in order for the network interfaces to works correctly, but otherwise seems to work with XE 3.2. I didn’t test much; at this stage I just wanted to see if I could get it going.

If you get a couple errors like dm-linear: Device lookup failed or mount: /dev/sdc1 already mounted or /export busy on XenEnterprise with Ubuntu Dapper, I suggest: apt-get remove -\-purge evms. See this bug report for some extra details.

I stopped using evms many years ago when it corrupted some of my data, lvm by itself its a much better system. I wish Ubuntu wouldn’t include it by default.

Sun have released their latest Xen update and it looks like it will be one of the key strategic platforms:

And that’s exactly the theory behind the newly bundled virtualization features in Solaris 10 – from Xen to ZFS, Crossbow to Java (fancy names for the same idea – reducing complexity to increase productivity). Solaris 10’s virtualization enables customers to consolidate the sprawling Linux, Solaris and Windows boxes laying around their datacenters, without having to pay exorbitant software licenses for add-on products. We built virtualization in to Solaris 10 not to encourage fewer computer or storage purchases, but instead, more – systems that are twice as utilized are twice as affordable. (When you double the mileage of a car, more people can afford it.)

Some details here and here. This thread in the beta forums has some useful context as well.

The most interesting new feature is NFS shared storage system based on VHD files and Live Migration (XenMotion). There is also iSCSI based shared storage and support for 64bit Windows clients. In order to deliver a product now XenSource have delayed releasing 64bit support for Linux clients and their new admin interface is Net2.0 base, thus Windows only. Currently they suggest that Linux users look at the xe cli client which has been improved to deal with many of the new features. Their final goal is a web based management system, if they did something REST based in rails it would be great.

I don’t have time to do any testing right at the moment, but I’ll be putting it though its hoops some time in the next month. One of the things I’m interesting in finding more information on is the new xva format. So I can do some work on a deployment system.

I noticed this entry in the Xen knowledge base about OVA:

XenSource Knowledge Base : Can you convert a virtual machine from Open Source Xen to your products?
There is currently no automated mechanism to move VMs from open source Xen to the XenSource commercial products. The upcoming OVA (open virtual appliance) format will allow VMs to be moved between different Xen environments.

OVA looks like it might be a useful way to define generic portable Xen images. Enomalism have some details about this as well. Other than that the only google stuff seems to be from June last year. Enomalism also have a link to this clever idea: rss to push vm images.

I just install the 3.2-beta of XenEnterprise by PXE. It was a faultless, follow the instructions process.  It is even possible to do an unattended installed. Even though XenEnterprise is a commercial product it has a certain linux-like quality which I find fits my preferred way of doing things.

Technorati Tags: xen

This has been sitting my drafts for a while. Might be useful.

I’ve collected a few interesting pages in providing remote booting with Vmware and Xen guests.

Using AoE and Etherboot. This is still work in progress.

http://www.coraid.com/support/linux/contrib/vantuyl/aoeboot.html

HOWTO: AOE in domU and boot from it. http://lists.xensource.com/archives/html/xen-users/2006-07/msg00595.html

My target environment is XEN, and the relevent parameters to be changed are:

ramdisk = "/boot/img.aoe"
root = "/dev/etherd/e9.0 ro"

(or whatever your aoe target happens to be… I think that was the vblade
default example).

http://www.emboot.com/products_winboot_i_FAQ.htm#q6

Can I PXE boot to an iSCSI target from within a virtual machine from VMware or Microsoft?

Yes, you can use winBoot/i to network boot VMware and Microsoft virtual machines from an iSCSI target. HBA-equipped systems hosting virtual machines generally do not allow sharing (or virtualization) of the HBA-capability within the vm environment. We recommend using our Managed Boot Agent on Disk (MBAoD) for VMs to PXE-enable the virtual NIC within the virtual machine.

http://www.emboot.com/VMware_howto.html