RE: vmware & Oracle

 
It is a fair point that it adds an extra layer, but they've invested a
huge amount of effort in mitigating that.  Also, it matters *what*
VMWare you're running.  Both workstation and server run their virtual
machines as processes - so there is a huge userspace jump, and IO is
definitely impacted.
 
In VMWare ESX server, the OS of the physical machine is a customized
version of Linux with a custom kernel, and the virtual machines have a
much more direct IO path, as well as typically the VMWare filesystem on
the physical machine, as opposed to a standard ext3 filesystem for
vmware workstation, etc.
 
So, if you look at IO impact statistics from someone, make sure they're
comparing the version of VMWare you'd want to run.
 
Matt



________________________________

        From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Allen, Brandon
        Sent: Thursday, July 19, 2007 12:52 PM
        To: Sean.oneill@xxxxxxxxxx; List, Oracle-l Freelists
        Subject: RE: vmware & Oracle
        
        
        I have no experience with it, but this comment from the list
archives indicates that vmware slows down I/O by adding an extra layer
between Oracle and the disks:
http://www.freelists.org/archives/oracle-l/01-2007/msg00094.html
         
        I'd be curious to see specific numbers from someone running a
fixed set of Oracle I/Os (e.g. a large table scan & a large index range
scan) against the same hardware with and without VMWare.  Anyone on the
list done anything like that to get precise timings?

Other related posts: