Re: VMs on external storage CPU overloading
john doe wrote:
> Hi Debians,
>
> I have limited space on my box, so I would like to install VMs onto an
> external storage (usbkey 3.0) using Libvirt.
>
> In the below command '/mnt/usbkey01' is the mountpoint for my usbkey:
>
> virt-install --name=try01 --ram=1024
> --disk=path=/mnt/usbkey01/machines/try01,size=6
>
>
> My CPU overloads like crazy.
>
> The overloading is related by the use of this usbkey but I don't
> understand why?:
> - Is this a Debian issue
> - Is this a Libvirt issue
> - Is this expected because I'm using virtualisation with KVM enabled
>
>
> Other then increasing the size of my internal storage, can I do
> something about it?
>
>
> If I change the path to '/var/lib/machines/try01' (internal storage) it
> works flowlessly and my CPU does not overload.
Two things:
- your CPU load, depending on how you measure it, may include
processes which are waiting for I/O. This I/O is very slow,
so.
- not all USB3 devices are the same. Many implement a
single-request system, where the kernel is only allowed to
make a read or write call, then wait for the response, then
issue the next call. Anything describing itself as a "key"
is particularly likely to have this.
Can you change your external storage?
-dsr-
Reply to: