On Mon, 22 Feb 2010, Troy Dawson wrote:

> Artem Trunov wrote:
>> Dear experts,
>>
>> It may not be SL specific, but I am sure there are a lot of experts here.
>> Have you had a good experience with KVM in the latest SL5.4? Is it
>> production-worthy?
>>
>
> It works for me, quite well actually.
>
>
>> I have the following issues:
>>
>
> One thing you haven't mentioned is what OS you are running on KVM.
> Note that all of my answers deal with SL3-SL5 and Fedora based virtual
> machines.
> I am runing on SL 5.4 with the latest kernels and security updates, but
> no fastbugs updates.
>
>> 1. Boot is only possible from ide bus, and drives are named hda. It
>> seems this is a feature of KVM?
>
> By default, this appears to be the case.
> It hasn't been an issue with me.
>
>> 2. Virtual machine can not use more than 1 host core, even if 2 virtual
>> cpus are configured for it.
>
> All of mine are setup to have 2 cpu's and they appear to be using them.
> How many physical CPU's do you have?  And how many cores per CPU?
>
>> 3. some times virtual machines lock up and go into a cpu curning loop,
>> consuming 100% of a host core. The solution is to kill qemu process.
>
> I haven't run into this except for when it is expected, like my virtual
> machines are running prelink, or compiling something.  Then I expect
> them to use up a whole CPU or two.
>
>> 4. virt-manager crashes shortly after first start up and few operations.
>> Subsequent restart of virt-manager doesn't lead to more crashes..
>
> I haven't ever run into this.  Sorry.
>
>> 5. It's slow, presumably because of disk operations. I see some 5MB/s
>> max read/write. I run a qemu native image format, stored on gpfs.
>>

All virtualization, no matter the technology, has overhead.  There is no 
free lunch.

-Connie Sieh
>
> Disk speeds are the slow point, particual when all my virtual machines
> want to access the disk at the same time.  But as long as they aren't
> all fighting for the disk they have been fine.
> I have no idea what my image format is.  I run mine as file images and
> build the file image in the virt-manager during the install.  So I'm
> running whatever the default is.
>
>> My host system has all latest kernels and patches.
>>
>> Thanks in advance,
>> Artem.
>
> I know I haven't answered too many questions, but hopefully it get's the
> conversation rolling along.
>
> Troy
>
>