Patch for setup_harddisks to use it for Xen-Domains "without disk"

[Henning Sprang]

Maximilian Wilhelm wrote:
>> Why not just use the solution for this described in the Wiki? That works
>> without changing the FAI code.
> 
> Because I have to edit a script each time I want to setup a Dom-U.
> Besides that you then have two ways of configuring disk stuff.

True, that's a downside.

The downside of setup harddisks is, that probably nobody will add
patches to it anymore...

But luckily, Storage Magic isn't far anymore...

>> Maybe, this patch might be interesting to make the file systems on these
>> partitions, which, in the wiki solution requires explicitly write mkfs
>> statements in the partition hook...
> 
>> Then again, not all people call their Xen disks xvd* - some use hd*,
>> some sd* - all three work. At least currently, I also heard that this
>> might change for some reason I did not fully understand - Fedora people
>> say using hda/sda is not good, and they, and suse use xvda IIR. Still,
>> the Debian tools for creating Xen DomU's use hda or sda, not xvda.
> 
> If you use a vanilla kernel the devices are called xvda.
> I don't know what $distro does.

I didn't test that yet, as I wanted to wait until xen integration is
really finished - I might have missed that point  but the last time I
looked at it, dom0 wasn't supported.

So that means with the vanilla Kernel, the domu config you set for the
disk's name doesn't have any effect anymore?


>> And a last note - if you want more complex partitioning in xen domains,
>> you can also just hand over the full disk, and give the domain a full
>> hda, and partition it as usual.
> 
> Sure you can, but in general this might not be the best idea.
> When you do partition a block device inside a Dom-U, you have to
> fiddle a lot if you want to access the file system from the Dom-0 in
> case your Dom-U is broken or you want to do $x.

There is a helper script included in the xen distribution
I don't know anymore why it isn't in the path on debian, I think I filed
a bug about this at some time.

Here it is at /usr/lib/xen-default/bin/lomount

I know, this doesn't work for netbsd partitions, but for linux
partitions it used to work quite good.

(I have the debianbase xen packages installed, it might be at some other
place with the standard debian packages).

Henning