Comments on: Just what are the important performance factors for Virtualization? http://blog.richardmcdougall.com/?p=27 Commentary on High End Systems and Virtualization Performance Sun, 08 Nov 2009 07:34:50 -0800 http://wordpress.org/?v=2.8.6 hourly 1 By: fleeludge http://blog.richardmcdougall.com/?p=27&cpage=1#comment-4872 fleeludge Sun, 19 Oct 2008 09:52:50 +0000 http://blog.richardmcdougall.com/?p=27#comment-4872 Hi people! The interesting name of a site - blog.richardmcdougall.com I today 7 hours looked in the Internet So I have found your site :) The interesting site but does not suffice several sections! However this section is very necessary! I have added you in elected! Forgive I is drunk :)) Hi people!
The interesting name of a site – blog.richardmcdougall.com
I today 7 hours
looked in the Internet So I have found your site :)
The interesting site but does not suffice several sections!
However this section is very necessary!
I have added you in elected!
Forgive I is drunk :) )

]]> By: Raymond Brighenti http://blog.richardmcdougall.com/?p=27&cpage=1#comment-1855 Raymond Brighenti Tue, 20 May 2008 23:08:20 +0000 http://blog.richardmcdougall.com/?p=27#comment-1855 Adrian I think you've answered your own question there. Managers can't figure it out... If you don't understand how to configure the host suitable to the guest OS's then you'll run into trouble... but then this also is a problem with physical boxes if they've been speced wrong, so no difference there. VM's need reboot for more memory, so do physical (yes some support it, but it's rare in the big picture of things) Host needing reboot and taking out 10 machines, well with VMotion and a SAN you can move them off to another hosts, update and reboot the guest, move them back and you're off again. One thing to remember that there will be new skills needed in managing a virtual environment, but they're not rocket science, it's more an extension of you're current skills looking after physical boxes. I've been in this job for over 10 years now and I can say Virtulization is a godsend to the med size businesses. Failover and HA for the masses! :) Adrian I think you’ve answered your own question there. Managers can’t figure it out… If you don’t understand how to configure the host suitable to the guest OS’s then you’ll run into trouble… but then this also is a problem with physical boxes if they’ve been speced wrong, so no difference there.

VM’s need reboot for more memory, so do physical (yes some support it, but it’s rare in the big picture of things)

Host needing reboot and taking out 10 machines, well with VMotion and a SAN you can move them off to another hosts, update and reboot the guest, move them back and you’re off again.

One thing to remember that there will be new skills needed in managing a virtual environment, but they’re not rocket science, it’s more an extension of you’re current skills looking after physical boxes.

I’ve been in this job for over 10 years now and I can say Virtulization is a godsend to the med size businesses. Failover and HA for the masses!

:)

]]> By: Adrian http://blog.richardmcdougall.com/?p=27&cpage=1#comment-139 Adrian Mon, 31 Dec 2007 23:55:48 +0000 http://blog.richardmcdougall.com/?p=27#comment-139 I think you need to add some more "illities". Observability is one of the biggest problems with virtualization, systems become unpredictable and unmanageable, and have performance related outages just because the administrators can't figure out how much headroom there is and how it is varying. Availability is the other one, how much downtime is needed to change various aspects of a VM/OS combination? e.g. Some OS's need a reboot if the VM adds more memory, others are dynamic. How about upgrades for the host system and VM itself? If you take out ten client VMs every time the host needs a reboot, you have created an issue. There is a trade-off between performance and availability. The more insulated the client VM is, the more available it can be, but there will be higher overhead, and slow periods during online maintenance. Cheers and happy new year Adrian Cockcroft I think you need to add some more “illities”. Observability is one of the biggest problems with virtualization, systems become unpredictable and unmanageable, and have performance related outages just because the administrators can’t figure out how much headroom there is and how it is varying.

Availability is the other one, how much downtime is needed to change various aspects of a VM/OS combination? e.g. Some OS’s need a reboot if the VM adds more memory, others are dynamic. How about upgrades for the host system and VM itself? If you take out ten client VMs every time the host needs a reboot, you have created an issue. There is a trade-off between performance and availability. The more insulated the client VM is, the more available it can be, but there will be higher overhead, and slow periods during online maintenance.

Cheers and happy new year
Adrian Cockcroft

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