> On 22 Mar 2021, at 14:30, Otto Moerbeek <o...@drijf.net> wrote:
> On Mon, Mar 22, 2021 at 01:47:18PM +0100, Mischa wrote:
>>> On 22 Mar 2021, at 13:43, Stuart Henderson <s...@spacehopper.org> wrote:
>>>
>>>>> Created a fresh install qcow2 image and derived 35 new VMs from it.
>>>>> Then I started all the VMs in four cycles, 10 VMs per cycle and waiting
>>>>> 240 seconds after each cycle.
>>>>> Similar to the staggered start based on the amount of CPUs.
>>>
>>>> For me this is not enough info to even try to reproduce, I know little
>>>> of vmm or vmd and have no idea what "derive" means in this context.
>>>
>>> This is a big bit of information that was missing from the original
>>
>> Well.. could have been better described indeed. :))
>> " I created 41 additional VMs based on a single qcow2 base image.”
>>
>>> report ;) qcow has a concept of a read-only base image (or 'backing
>>> file') which can be shared between VMs, with writes diverted to a
>>> separate image ('derived image').
>>>
>>> So e.g. you can create a base image, do a simple OS install for a
>>> particular OS version to that base image, then you stop using that
>>> for a VM and just use it as a base to create derived images from.
>>> You then run VMs using the derived image and make whatever config
>>> changes. If you have a bunch of VMs using the same OS release then
>>> you save some disk space for the common files.
>>>
>>> Mischa did you leave a VM running which is working on the base
>>> image directly? That would certainly cause problems.
>>
>> I did indeed. Let me try that again without keeping the base image running.
>
> Right. As a safeguard, I would change the base image to be r/o.
>
> I was just looking at your script and scratching my head: why is Mischa
> starting vm01 ...
>
> -Otto
Normally I don’t use derived images, was a way to get a bunch of VMs running
quickly to put some more load on veb/vport.
I have moved vm01 out of the way to vm00 and redid the whole process.
Seems much better now.
Thank you all for showing me the way. :)
Mischa
