On 24/10/2014 2:59 PM, Orion Poplawski wrote:
> On 10/23/2014 09:05 PM, Steven Haigh wrote:
>> On 24/10/2014 1:59 PM, Orion Poplawski wrote:
>>> On 10/22/2014 03:23 PM, Steven Haigh wrote:
>>>> Hi all,
>>>>
>>>> I'm wondering - I'm looking to simplify my Xen DomU installation via a
>>>> kickstart file...
>>>>
>>>> As my Xen config has /dev/xvda - which should be formatted as ext4 and
>>>> used as / - is there any options that I can achieve this?
>>>>
>>>> Just about everything I've stumbled across does partitioning first -
>>>> and
>>>> not the entire disk. Without supplying a kickstart file, the installer
>>>> will bail saying no disks found.
>>>>
>>>> It's been this way for MANY years, but I heard rumours of a magical
>>>> kickstart option - but I can't seem to find it...
>>>>
>>>
>>> What do you have against partitioning the disk?  Loosing the 512-bytes
>>> for the partition table?
>>
>> On some setups it can cause major write degradations in the virtual
>> machine.
>>
>> If you can imaging the disk being set up in 4Kb clusters - which LVM
>> then adheres to - but on the DomU disk with a partition, the alignment
>> for partition data is now 0 + 512 bytes instead of 0.
>>
>> This means a write of 4Kb would write two sectors to the physical disk
>> (first being 512 bytes + 4Kb, the second being the 512 bytes that give
>> us an offset).
>>
>> In lame ASCII art, this means:
>>
>> Plain Disk:
>> 0-----------512-----------1024-----------1536-----------2048 etc
>> Whole disk write:
>> ----------------------------------------------------------> to 4Kb
>> Partitioned disk write:
>> [  part tbl  ]--------------------------------------------> to 4Kb + 512
>> bytes
>>
>> Its good to get your sectors aligned.... Especially when its on a RAID
>> backend that also has a stripe size as well...
>>
> 
> Hmm, that is an issue.  I assume you've tried:
> 
> part / --onpart /dev/xvda
> 
> You may also be able to partition in %pre manually with GPT or dos with
> your desired alignment.

For the record, I did manage to get this going:
## Wipe the disk completely and use the whole disk in ext4 config.
zerombr
clearpart --all --drives=xvda
part / --fstype="ext4" --onpart=xvda --label=root
bootloader --location=none

One point though is that you have to make your own 'grub.conf' for Xen
to use in booting the system. This isn't really an issue though -
because you only need a template - the kernel updates will update the
template once created.

Now I've got it happening ok - its actually quicker to do a KS install
than it was to untar my xz archive of a template system :)

> Having tried using full disk for things like md raid and lvm in the past
> an gotten burned by loosing most autodetection I've given up on not
> partitioning.

Heh - I'm the other way :)

-- 
Steven Haigh

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Web: http://www.crc.id.au
Phone: (03) 9001 6090 - 0412 935 897