[et-mgmt-tools] new feature: creating multiple virtual disks for a koan VM

[Michael DeHaan]

Using the latest source of Cobbler and Koan (which will be 0.6.2), the 
following examples of adding more than one disk to a virtual machine are 
now possible.  

# request three seperate disk images, 5 GB each
cobbler profile add --name=foo --distro=bar 
--kickstart=/etc/cobbler/baz.ks 
--virt-path=/opt/foo/A,/opt/foo/B,/opt/foo/C --virt-size=5

# request one disk as a loopback in /opt/foo, another on partition 
/dev/sda4, using 5 GB each
cobbler profile add --name=foo --distro=bar 
--kickstart=/etc/cobbler/baz.ks --virt-path=/opt/foo,/dev/sda4 --virt-size=5

# (the following example actually needs some tweaking but will work soon)
# request two disks on VolGroup00 using 5 GB and 6 GB
cobbler profile add --name=foo --distro=bar 
--kickstart=/etc/cobbler/baz.ks --virt-path=VolGroup00,VolGroup00 
--virt-size=5,6

As in previous versions, if you don't pick a value for --virt-path in 
either koan or cobbler, koan will pick a file in either 
/var/lib/xen/images or /opt/qemu
that is named after the MAC address of the virtual system.   When you 
don't set a --virt-path, you get one disk every time.

As an aside: here's how you can specify --virt-path in koan to override 
what was set in cobbler:

koan --virt --profile=F-7-i386 --server=bootserver.example.org 
--virt-path=VolGroup01,VolGroup02

As you can see, the syntax looks exactly like it does in Cobbler.   Any 
value Cobbler had for --virt-path would be overriden.   Note that 
--virt-size still needs
to come from Cobbler.    Rather intentionally, the number of things that 
can be overriden in koan is kept to a bare minimum. 

Note that if you specify only one value for --virt-path in Cobbler (say 
"5", for "5 Gigabytes") and the user requests two disks, they'll both be 
5 gigabytes in size.
This is to be able to

If you don't need multiple disks, the old commands still work when 
single values are left ... and the defaults still work the way they used to.
If the above doesn't make sense, let me know.   In general this is not 
something most folks will need, but for the ones that do, there you go...

Thanks!

--Michael