better platform for virtualization

[Gilboa Davara]

On Sun, 2010-01-17 at 17:49 +0200, Michael Lewinger wrote:
> Hi there,
> 
> I'd like to ask your oppinion on the virtualization of several WINDOWS
> servers installed on a client's medium business server room. There are
> about 6 crucial servers (priority, exchange, file server, and some
> others) that need to be accessible when they fail. Currently, each
> server has its own RAID storage. There is only 300GB of data to be
> kept on those servers (mostly exchange and file server). The
> virtualized servers should become alive when one of those main servers
> dies, and theoretically, no more than 2 VMs should be running in
> parallel.
> 
> What would be the best virtualization platform for such a
> requirement ? Windows 2008 server, or XEN ? 

The safe choice would be the free VMWare Server (They bill only for
support).
But I've grown to dislike it since the release of version 2 for a couple
of reasons:
A. Their web interface is slow and buggy.
B. Their package installers bypass the OS package manager and installs
far-too many dependencies.
C. At least in previous versions, it was more-or-less required to
disable SELinux in-order to get it work.
D. VMWare tends to be slow in supporting new kernels. Very slow.

As such, I'd advise that you take a close look at KVM/VirtManager that
comes as a part of RedHat Enterprise Linux 5.4 (and CentOS 5.4).
At least in my experience, KVM gives near native performance and works
more or less out of box as long as you have fairly recent hardware.
(Core 2, 7i, Xeon x3xx, x4xx, x5xx, AM2/3 AMD Athlon64 and AMD Opteron
2xxx/8xxx).

Oh, as far as I remember, KVM also has support for NFS/ISCSI and live
migration.

> Would a fast single Xeon processor be able to handle this
> requirements ? 8GB or 4GB ?

It greatly depends on how much load these servers are expected to
handle.
I'd add a lot of memory. At least 8GB.
A quad core Xeon should be sufficient to handle 2-4 VM's.

Heck, I've got a dual core Athlon64/4GB that is currently running 3 VM's
without breaking a sweat.

> Would you consider VMWARE on top of CENTOS ?

As I said above, I greatly dislike VMWare Server 2 (see above) so I
can't really recommend it. (Unless you are talking about the bare-metal
VMWare ESX)

> Would you suggest that the data should already be kept on a NAS
> appliance as of now, even before DRP takes place ?
> (If yes), which NAS solution would you use ?

It greatly depends on the load these servers are putting out.
Anything from a simple software SATA RAID5 running on top of a Linux
running SAMBA/NFS/ISCSIT to a big iron EMC closet will do.

> Would you consider a cloud-based backup program such as Crashplan to
> backup this data ? Is there any other enterprise-level backup app that
> can store backups on cloud storage ?

Out of my league :)

- Gilboa