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Re: [Xen-users] Re: Partition vs disk images

> On Tue, Apr 29, 2008 at 10:15 PM, Fajar A. Nugraha <fajar@xxxxxxxxx> wrote:
> In RHEL 5 at least, anaconda requires the block device/file to be mapped as 
> disk (e.g hda, sda) not partition (e.g. sda1). Try changing it to
> disk = [ "phy:lvm-raid/FileVolGroup,sda,w" ]

 Ok, so (at least in CentOS/RHEL?) the Xen domU sees the dom0
partition not as a partition but as a physical disk?  sda1, sda, and
hda all failed (sda1, sda were not visible while hda kept generating
installer errors detecting the drives).  hda1 shows up as weirdly
named disk  (/dev/hda1) that I need to partition out in the domU
installer (ie, /dev/hda11, /dev/hda12, etc).

disk = [ "phy:lvm-raid/FileVolGroup,hda1,w",
         "phy:lvm-raid/io-swap,hda2,w" ]     # assumption was that
these were partitions...

What concerns me is that if/when I want to grow disk available to a
domU (this on in particular is a file server), I can't just grow what
shows up as hda1, right?  I'd need to add a new "disk" and extend a
LVM within the domU?

Don't these layers of RAID+LVM (dom0) and Xen block device and LVM
(domU) come at a price?  I was hoping that the partition got mapped
straight into the domU so I avoided any extra stuff within the domU
and I would have the added bonus of being able to mount the drives and
copy files between when setting this up.

> Having said that, if you're building lots of identical domUs, using prebuilt 
> template (and mappingthe block device  as sda1 instead of sda) should be 
> faster than installer.

If I can only do partitions, how does this work then?  Unless all the
drives are identical in size and I 'dd' the device??


P.S. Sorry, Fahar, I didn't mean to send directly to you... :-)

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