Re: [vserver] tcpdump, top, mpstat, iostat

From: Christian Balzer <>
Date: Fri 07 Jan 2011 - 05:19:14 GMT
Message-ID: <>

On Fri, 7 Jan 2011 12:46:27 +0900 Andrej van der Zee wrote:

> > yes, but would be a waste of resources (to have a
> > separate device for each guest).
> Yes true, but in terms of performance i would rather not have to guests
> competing for one disk head in particular for disk intensive apps such
> as a database server.
That, like many things "depends", but unless all of your guests are I/O
bound all of the time a shared resource will be faster.
Take this example:
Given that are 8 disks in this example system the best degree of I/O
separation achievable would limit you to 8 Vserver guests. Now that also
leaves you with 8 single points of failure, but lets ignore that for the
moment (but not real life! ^o^).
Say one of your guests is indeed a busy DB application, the others do
random, but not constant heavy I/O.
The single disk assigned to the DB guest will of course never be anywhere
near as fast as a RAID comprised of all the 8 disks (preferably a RAID10,
but even RAID5 would be faster).



Christian Balzer        Network/Systems Engineer          	Global OnLine Japan/Fusion Communications
Received on Fri Jan 7 05:19:28 2011
[Next/Previous Months] [Main vserver Project Homepage] [Howto Subscribe/Unsubscribe] [Paul Sladen's vserver stuff]
Generated on Fri 07 Jan 2011 - 05:19:29 GMT by hypermail 2.1.8