Re: [Xen-users] New to Xen, looking for advice regarding system configuration

[Braindead <Braindead@xxxxxxxxxxxx>]

On Tue, 12 Jul 2011 21:08:37 +0700 "Fajar A. Nugraha" <list@xxxxxxxxx> wrote:
> On Tue, Jul 12, 2011 at 7:59 PM, Braindead <Braindead@xxxxxxxxxxxx>
> wrote:
> > My main purpose would be to support my software development and
> > consulting work.  So I need to be able to run various OS's.  I
> > don't develop games so no need for any fancy graphics.  I'm used to
> > the limitations of virtual machines (use VMWare a lot for dev
> > purposes) and I'm fairly sure Xen can do everything I need.
> >
> 
> You haven't said why you want to move away from vmware. If we know
> what your priorities are, we might be able to give better advice. For
> example, if you're used to vmware-style GUI, but want an open-source
> license, XCP might be a better choice. But it you want something you
> can tinker, or use bleeding-edge technology, then starting with a
> distro that includes Xen would be a better choice.

I use VMWare workstation at work, I use virtualbox on Linux a bit.  I only 
mention VMWare to note that I'm used to the concepts of VM's.  I prefer running 
*nix, Gentoo to be precise.  

My home server is running a ton of services (subversion, mail, http, backup, 
router, ossec, nagios, dns, dhcp..etc) and for sanity's sake I'd like to break 
that up into multiple servers.  I also need a few windows boxes (various 
configs, versions).  

Goal is to consolidate things into one box, and have a complete backup box as 
well.  Thus virtualization.  The XEN 'near bare metal' performance is what I'm 
interested in, and definitely into optimizing every aspect I can which is why I 
use a source distro.


> > I expect to have 2-3 virtual machines running most of the time,
> > possibly 2 working hard (for example restoring a gig+ database
> > backup on one while programming/doing other tasks on another).
> >  I'll be purchasing 2 identical machines one as a backup, so I
> > don't need any extra 'robustness' that a server motherboard/system
> > would provide.  Which leads into the following question.
> >
> > Would it make sense to spend extra bucks on a multi processor
> > motherboard rather than going with a single Core i7 or the like?  I
> > think there are i/o bandwidth benefits with multi processor boards,
> 
> Is there?

Not sure, which is why I'm askin ;-)

> IIRC the main selling point of server-grade motherborad used to be the
> ability to use ECC RAM. But now some motherboards for i7 support ECC
> RAM and SATA III.

Many include system monitoring and alerting capabilities in the BIOS (or at 
least used to, it's been a while since I've worked on server grade hardware).


> > however due to a lot of database grinding I tend to do I suspect
> > that disk i/o is a limiting factor in my case which I'll try to
> > deal with somewhat by RAID0 over 4-5 fast drives.  I don't need any
> > redundancy as all variable data (code and the like) is on remote
> > servers and already fully backed up.
> 
> ... which brings another point. If you know you're I/O-starved anyway,
> why not use SSD? Pure SSD implementation can easily give 10-100x IOPS
> of HDD. And since you say you'll have an identical machine as backup,
> if you're worried about SSD lifetime, you can have HDD on the backup
> machine.

Well, i'd love to...but ;-) My current dev machine has 2TB of databases sitting 
on it that I may need access to at any given time.  I could move them as needed 
onto SSD however that would take a lot of time much more than just accessing 
them directly on the slower media.  Might be doable as some sort of hybrid 
setup (some SSD's, some regular HD's) however that would likely just confuse me.
 

> Another option would be using SSD as cache, with something like
> facebook's flashcache. This setup would reduce the possibility of data
> loss (since SSD will only be cache), and have the additional benefit
> of higher capacity (compared to pure SSD setup), but is also more
> complex and (depending on how you look at it) "experimental".

Isn't that what the 'hybrid' drives are?  I'd think those would work outta the 
box, should look just like a regular drive to the OS I'd think?

> > Do folks generally install X11 on Dom0 so they can get a gui
> > VNC/remote desktop into Windows DomU machines?  Or is there some
> > other mechanism available?
> 
> Generally speaking you don't need full-blown X desktop on dom0. It can
> be headless with "minimum" software installed. VNC console of domU is
> provided by QEMU, not by X desktop on dom0.

Ah, one question that has a simple answer ;-)

Thanks for the thoughts and suggestions.  I know hardware config is complex, 
and depends highly on how things are used...  

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users