Is it possible to have a Xen host server connect to a fiber SAN instance as an extra LVM disk, then allow the Xen host to offer this as either a partition or logical volume (LVM) instance to a Xen guest VM? Here's a sort of idea I am looking at...
EMC SAN Storage
+ Xen Host --> Mounted as vg01, offered as /var/lib/xen/images/extra-
+++ Add new drive to Xen Guest as "tap:aio:/var/lib/xen/imag
++++ Xen Guest --> pvcreate /dev/xvdc, vgextend vg00 /dev/xvdc, etc...
Xen Host and Guest VM is running RHEL 5.3. Xen version installed is 3.0.3.
The use of iSCSI is not possible and at last check, the QLogic driver for RHEL has a buggy/unstable state so that it's not really production ready.
Here's what one of our Xen Guest VM's look like, using a 'dd'-based two-drive setup on the Xen Host:
name = "devx14"
uuid = "7d238700-19b7-b357-f759-dcaefc02fe2e"
maxmem = 4096
memory = 4096
vcpus = 2
bootloader = "/usr/bin/pygrub"
on_poweroff = "destroy"
on_reboot = "restart"
on_crash = "restart"
vfb = [ "type=vnc,vncunused=1,keymap=en-us" ]
disk = [ "tap:aio:/var/lib/xen/images/devx14.img,xvda,w", "tap:aio:/var/lib/xen/images/devx14-mysql.img,xvdb,w" ]
vif = [ "mac=00:16:3e:1b:ab:9b,bridge=xenbr0" ]