[clue-talk] I'd like opinions on VM software

[Crawford Rainwater]

----- clue-talk-request at cluedenver.org wrote:
> Date: Sat, 20 Dec 2008 14:15:26 -0800 (PST)
> From: Brian Gibson <bwg1974 at yahoo.com>
> Subject: Re: [clue-talk] I'd like opinions on VM software
> 
> 2.5 GHz Core 2 Duo (guest OS gets one core when active?)
> 2 GB RAM (this will be upgraded later on because it seems the sweet
> spot is 1GB per guest OS, 512MB is the recommended minimum)
> 200 GB HD space (plenty of space)
> 

What that I would recommend 2-4 virtual machines tops depending on how you decide to allocate the resource per virtual machine.  You can add more RAM (VMware Server v2.0 allows up to 8GB; Xen is quite larger as well).  Per memory, VMware Server has a limitation of 2CPU's per virtual machine, Xen is a bit more open.  Since I have not worked with Parallels nor VirtualBox I cannot comment on those.

> I primarily need it for web development, nothing that should tax a GPU
> so 3D isn't really a consideration.  
> 

If you are going to just do a web server (i.e., LAMP style) the GPU would not matter save on the client side.  If you are going to use the virtual machines for graphics related work though, that would be a consideration indeed.

> Linux, XP, and Vista are the most likely choices for guest OSes; you
> can only virtualize Mac Server on Apple hardware and I'm not
> interested in Server.  I figure a minimum of 20 GB per guest OS though
> the XP one may be larger for some applications like Photoshop assuming
> I can't get it to run decently under WINE.  Seamless Windows
> (VirtualBox), Coherence (Parallels), and Unity (VMWare) are cool
> features for that.  It would be ideal if my home directory is
> accessible to/from each guest OS, but if each guess OS has it's own
> partition instead of just being a file and that partition is readable
> from the host OS, then it's not that big a requirement.
> 

You can share out via NFS and/or Samba between virtual machines and hosts quite easily.  VMware Server also has a "host mount" feature as well to the "bare metal" or localhost system.  The constraints with VMware is one you allocated a hard disk partition, it is typically fixed in size.  Xen allows use of LVM under Linux, thus you can use a LV (Logical Volume) and adjust accordingly.

> 
> I essentially want to run different browsers for different OSes and
> also
> run the occasional Windows app that doesn't work well under WINE. 
> Nothing terribly intensive.
> 

VMware Server on a Linux host can do such.  I would recommend not running the Vista and XP sessions at once though to reduce the constraint on your current resources.  Xen will run Windows 2003/2008 Server as virtual machine guests, but I am not sure about the XP and Vista workstation.

A minor note, you might want to turn on the virtualization flag within the CPU at the BIOS level as well.  Then you will have HVM or FV (basically "full virtualization") and get more bang for your buck out of the CPU.

Finally, typically when one wants to virtualize whether it be VMware, Xen, or who ever, the host systems should be dedicated to just that, nothing more save internal operation and support of the virtualization application.  By making an "all in one" or "Swiss Army" style of a box, this reduces the effectiveness of the virtualization as a whole.  I would recommend a guest system for "other things" (i.e., LAMP server).

HTH some more and FWIW.

--- Crawford
PS: The usual disclaimer...pardon the delays as I get this list in Digest format.