Anyone Actually Using Virtual Linux Servers?

[Jarod Wilson]

On Sep 09, 2007, at 00:51, Kristian Erik Hermansen wrote:

> On 9/8/07, Jarod Wilson <jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org> wrote:
>> Of course, putting 16 drives in a RAID0 array is an insanely bad
>> idea, due to the high probability of drive failure and the data loss
>> on all 64 guests... I certainly wouldn't call it ideal, anyhow... :)
>> I'm a big fan of RAID6 these days.
>
> Well, in mine and his case, the data is not that important.  The data
> lives for a little while, and then becomes irrelevant.  Thus, RAID6
> would actually be detrimental.  And as we know from Google's research,
> just backup frequently and store your data in at least three
> locations, rather than using RAID.  Of course, if you have highly
> critical servers, you would not do this.

My personal use cases are my web and mail server and my myth backend.  
RAID6 for me in both (well, the video store on my myth backend is  
actually raid5 w/a hot spare, since my 3ware card is a slightly older  
one that doesn't do raid6).

> But, in those cases, you
> have more expensive, and "ideal" solutions, such as VMware ESX Server
> with VMotion...

True.

>> As for xen... I'd not touch it outside of an implementation with  
>> long-
>> term support (i.e., RHEL5 or SLES10, not sure if Ubuntu 6.06 LTS has
>> xen or not), where you have something of an assurance that updating
>> your host OS isn't going to make your guests asplode...
>
> This is one of the reasons why such virtualization technologies should
> be carefully considered.  Such a scenario would not occur in VMware,
> since the guest is not intimately tied to the host.  You already
> should know this because your kernel image is appended with -xen.
> That should give you a hint.  Maybe kvm will work better for you when
> it is more mainstream, as there is less dependency.  Until then, you
> can use VMware, which is merely a virtualized disk image, with no
> kernel interdependency.

I frequently use kvm on my workstation when I need to spin up a  
virtual machine. Its actually easier for me to deal with than vmware  
(workstation, in this case), since everything is already in-kernel  
and I tend to be running the latest and greatest upstream bits, so  
the vmware-any-any patches don't always work...

Oh, and trust me, I know all too well just how fragile xen can be  
without being very careful about what bits you're mixing -- a large  
part of my day job these days includes working on ia64 xen. :)

> And Ubuntu Hardy Heron 8.04 LTS will appear next April for those
> looking to upgrade from Ubuntu Dapper...

Out of curiosity, does HH include xen and/or does the prior LTS release?

-- 
Jarod Wilson
jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org