[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-users] Cheap IOMMU hardware and ECC support importance

On 30/06/14 20:06, Gordan Bobic wrote:
On 06/29/2014 08:12 AM, lee wrote:
Gordan Bobic <gordan@xxxxxxxxxx> writes:

On 06/28/2014 08:45 AM, lee wrote:

I am not a fan of virtualization for most workloads, but sometimes
it is convenient, not least in order to work around deficiencies of
other OS-es you might want to run. For example, I don't want to
maintain 3 separate systems - partitioning up one big system is
much more convenient. And I can run Windows gaming VMs while
still having the advantages of easy full system rollbacks by
having my domU disks backed by ZFS volumes. It's not for HPC
workloads, but for some things it is the least unsuitable solution.

Not even for most?  It seems as if everyone is using it quite a lot,
make it sense or not.

Most people haven't realized yet that the king's clothes are not
suitable for every occasion, so to speak. In terms of the hype cycle,
different users are at different stages. Many are still around the
point of "peak of inflated expectations". Those that do the testing
for their particular high performance workloads they were hoping to
virtualize hit the "trough of disilusionment" pretty quickly most of
the time.

Why would they think that virtualization benefits things that require
high performance?

I don't. But many people think it makes negligible difference because they never did their testing properly.

When I need the most/best performance possible, it's
obviously counter productive.

Apparently it's not obvious to many, many people.

Virtualisation also lends itself nicely to helping improve uptime. ie, physical hardware failure of the dom0 will crash the domU's, but you can restart the domU's on another dom0 (as long as you use a SAN, or replicated storage/etc).

I also noticed a lot of talk about remus some time ago, and thought it looked really promising. Having a quick look at http://wiki.xen.org/wiki/Remus shows that it is still getting better. When that arrives, you won't have any downtime due to dom0 failure (though I guess you need to double the resources).

PS, this is my personal advantage of using virtualisation... If I need n servers to run all my VM's, then with n+1 I can survive a failure of a dom0 (albeit with a reboot of the VM's being run there at the time). I still get to save on overall hardware requirements, as well as being able to live migrate for scheduled hardware maintenance/etc.

Adam Goryachev Website Managers www.websitemanagers.com.au

Xen-users mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.