[asterisk-users] Need to pick your brain for recommendation on using 2.5" or 3.5" HDDs for Asterisk server...

[Dmitry Nedospasov]

Hey Bruce,

On Sun, Sep 26, 2010 at 01:48:40PM -0400, bruce bruce wrote:
> I am stack between two identical systems (2U Twin2, 4 nodes, SuperMicro)
> servers that have the same exact specs except for HDDs. These nodes will all
> either have Asterisk installed with CentOS or will have Asterisk install in
> virtual environment.
> 
> Option 1: *12* x 3.5" HDD (3 HDDs per node)
> Option 2: *24* x 2.5" HDD (6 HDDs per node)
> **both options come to the same price.

I'm not sure why disk access (especially in the SAS age)
should be a limiting factor. I reckon the only thing that you need to
consider is the ammount of CPU horsepower that you'll need.

> Other than the price difference (2.5" is more expensive and can't find many
> of the 1TB or so....) is there any preference, advantage, or disadvatage of
> chosing 2.5" HDD or 3.5" when it comes to the server operations or Asterisk
> operation?

And another question would be, why you would need so much disk space? :)
Keep in mind, that if this is going to become the cornerstone of your
virtualization infrastructure, then its totally different. Though keep
in mind the security implications of consoldation, i.e. Security First!

> Each node of this server will be running CentOS 5.5 either in 64 or 32 bit +
> Asterisk or they will be used for virtual environment where multiple
> instance of Asterisk will be installed within CentOS XEN.

Ah, good choice here. CentOS with Xen is what I run as well on one of my
installations. If you want to get the latest Xen Versions, especially if
you're just testing, make sure to take a look a look at the gitco xen
repositories [1]. They'll get you up and running real quick. Trust is
another question, which I'll leave up to you ;)

[1] http://www.gitco.de/repo/ 

For domUs, I run debian/ubuntu, because of xen-tools [2] (shameless
plug, I'm an author) with which its really easy to make "disposable",
minimal VMs. Though there are only xen-tools packages for debian,
installing it on CentOS is really, really easy, like I said I do it on
one of my installations.

[2] http://xen-tools.org/
[3] http://gitorious.org/xen-tools/xen-tools

So thats one way to go, and I did just that for one of my installations,
but that was a while back. This may be a discussion for another forum
(no pun intended), but I would like to emphasize, that it might be
worthwhile to take a look at Debian Squeeze (Currently testing, but near
release) as your dom0 of choice. As you must know by now, Red Hat
dropped Xen in RHEL and CentOS will do the same in the next itteration.
Debian on the other hand seems to have the best and most commited Xen
support nowadays.

With Debian Squeeze you get a 2.6.32 kernel (and the 2.6.18 of CentOS
*shudders*) and you also get Xen 4. One other alternative that turned up
recenty on the xen-tools mailing list, which sounded very good, was
Debian Lenny with a 2.6.32 from backports and a self-compiled xen 3.4.

I mean you could also get XenServer of course, however don't ask me
about the licensing.

In any case, Xen shouldn't slow you down enough to matter, so I would
definately virtualize to have more options. Just remember to disable
checksum offloading, the ancient xen bug [4][5] ;)

[4] http://wiki.xensource.com/xenwiki/XenFaq#head-4ce9767df34fe1c9cf4f85f7e07cb10110eae9b7
[5] http://lists.xensource.com/archives/html/xen-users/2006-04/msg00032.html

To sum things up, I think virtualization is a good idea, especially when
you have beefy servers (I do it too). So a green light from me!

All the best,

D.
-- 
Dmitry Nedospasov <dmitry at nedos.net> -- Twitter: @nedos
Web: http://nedos.net -- Github: http://github.com/nedos