Re: VM Performance after Template Upload

[Mevludin Blazevic <mb...@uni-koblenz.de>]

Hi,

using ACS with KVM and RBD/Ceph, it turns out that the user has chosed a 
Compute Offering with volume type "Fat" provisioned. After he reinstall 
the VM from the template using a Compute Offering with Volume "thin" 
provisioned, the performance level was as high as the other VMs. Seems 
like there is a huge performance difference between fat and thin, 
however, I have not tested out the "sparse" option. I always thought 
using RBD as primary storage there is no difference between fat and thin...

Regards,

Mevludin

Am 07.09.2022 um 15:01 schrieb Nux:
> Hi,
>
> Check that the templates were registered with the appropriate profiles 
> (ie of type CentOS7 etc), particularly if their storage and network 
> devices are Virtio ones.
> You can do this with lspci on Linux - inside the VM - ethernet and 
> storage should present themselves as "virtio" or similar.
>
> Another thing you can look at, is whether the qcow2 file they upload 
> is funky in any way, ie look at compat, cluster_size and compare with 
> a file in your cloud that you know works well. You can use "qemu-img 
> info file.qcow2" for this.
>
> hth
>
> ---
> Nux
> www.nux.ro
>
> On 2022-09-07 13:26, Mevludin Blazevic wrote:
>> Hi all,
>>
>> some of our users have reported that after they uploaded QCOW2
>> templates to our ACS environment and started a VM from the template,
>> the VMs ran very slow. In contrast, VMs installed directly in ACS
>> using ISOs for example are very fast. I wonder if something in the
>> upload view was misconfigured by the users.
>>
>> We are using KVM and in the upload view we can choose Root disk
>> controller, OS Type and other options like enabling HVM. Any ideas?
>>
>> Best Regards
>>
>> Mevludin