[CentOS-virt] new to xen - got questions, please

Wed Jun 16 16:53:23 UTC 2010
Mark Pryor <tlviewer at yahoo.com>


--- On Wed, 6/16/10, Steve Campbell <campbell at cnpapers.com> wrote:

> From: Steve Campbell <campbell at cnpapers.com>
> Subject: [CentOS-virt] new to xen - got questions, please
> To: centos-virt at centos.org
> Date: Wednesday, June 16, 2010, 9:11 AM
> I just installed Centos 5.5 with the
> xen kernel on an older machine. It 
> has Xeon processors and a 700 Mhz processor speed, so I
> realize I must 
> use para-virtualized guests. Reading the Centos/RH
> Virtualization Guide 
> gives examples of the process of installing guest hosts,
> but it only 
> lists installing Windows as a fully-virtualized host.
> 
> Is that because they only showed those types of examples or
> is it that 
> Windows hosts can't be para-virtualized?
> 
> Secondly, what's the normal what to install a Centos guest
> when it comes 
> to defining the installation media (it lists HTTP, FTP, or
> NFS). This 
> machine only has a CD drive, so I'm a little confused about
> the best way 
> to handle this since the Centos installation now consists
> of 6 CDs. A 
> brief explanation would be handy.
> 

You want to boot into a PV install. The initrd.img and vmlinuz shown
in the filelist below are the tools for this included on the first
CD in the set.

------------------ locate netboot boot files -----------
tlviewer at ga-p45:~> sudo mount /data2/kvm/CentOS-5.5-i386-bin-1of7.iso /mnt/iso -o loop
tlviewer at ga-p45:~> ls -al /mnt/iso/images/xen/
total 9573
drwxr-xr-x 2 root root    2048 2010-04-29 17:29 .
drwxr-xr-x 4 root root    2048 2010-04-29 17:29 ..
-rw-r--r-- 2 root root 7552658 2010-04-29 17:23 initrd.img
-r--r--r-- 1 root root     441 2010-04-29 17:33 TRANS.TBL
-rw-r--r-- 2 root root 2244980 2010-04-29 17:23 vmlinuz
------------------ snip -----------

copy the above 2 to a local dir

#cat cent55.py
------------------- cent55.py ---------
kernel = 'vmlinuz'
ramdisk = 'initrd.img'

name = "cent55"
uuid = "442db20d-7a82-409b-b8aa-a352c1fe127c"
maxmem = 512
memory = 512
vcpus = 2
#bootloader = "/usr/bin/pygrub"
#bootargs = "-q"
on_poweroff = "destroy"
on_reboot = "restart"
on_crash = "destroy"
vfb = [ "type=vnc,vncunused=1,keymap=en-us" ]
disk = [ "phy:/dev/maxvm/cent55,xvda,w" ]
vif = [ "bridge=br0" ]
extra = " install=http://mirrors.kernel.org/centos/5.5/os/i386/ console=tty0 console=ttyS0,38400n8 console=xvc0"
----------------- unsnip --------------

#xm create -c cent55.py

this will start an http PV install. AFAIK the boot files are netboot only and won't allow access to your CD as ISO or otherwise.

Before firstboot, comment out the kernel/ramdisk lines and uncomment the 2 pygrub lines.

-- 
Mark