Comments on: Citrix XenServer for the ESX Engineer

By: Aaron Delp

Aaron Delp — Tue, 23 Sep 2008 16:48:57 +0000

James - Thank you very much!!

By: James

James — Tue, 23 Sep 2008 15:59:36 +0000

XenServer 5 is out now. Adds loads of features, check it out. http://www.xenserver5.com

By: Hyper-V vs. ESXi in the Small Business space » Lukas Beeler’s IT Blog » Blog Archive

Mon, 11 Aug 2008 08:48:28 +0000

[...] Citrix XenServer for the ESX Engineer [...]

By: Aaron Delp

Aaron Delp — Mon, 04 Aug 2008 18:52:07 +0000

Roger and Matt - I have updated the post to reflect your concerns and clarifications. Thank you very much for contacting me! Please look it over and let me know if there is anything else that is inaccurate. Also, my current knowledge base only extends to the current version. I would be happy to keep this up to date as XenServer 4.2 is released. Thank you!

By: Matt Darlington

Matt Darlington — Fri, 01 Aug 2008 20:11:44 +0000

Cold migration is not an issue.

By: Scott Lowe

Scott Lowe — Fri, 01 Aug 2008 18:40:33 +0000

Roger, I understand your comments about CPU flags preventing migration from AMD to Intel or vice versa (and you’re right, it does affect all hypervisors with regard to live migration). But how is this applicable even in a cold migration?

By: Roger Klorese

Roger Klorese — Fri, 01 Aug 2008 15:25:05 +0000

And “string” was a bit typo-y… I meant “a bit strong,” of course. Duh. Fingers not working.

By: Roger Klorese

Roger Klorese — Fri, 01 Aug 2008 15:11:19 +0000

Another “in the beta” answer: up to a year of performance data, in standard RRD format, delivered in XML over a web service.

And: there’s more flexibility in NIC assignment, but our work has shown that there isn’t that much traffic or lag to live migration dictating the use of a dedicated NIC.

By: Roger Klorese

Roger Klorese — Fri, 01 Aug 2008 15:09:21 +0000

And, sorry, when I started to answer I hadn’t intended there to be so many “in the new beta” answers… so “misconceptions” was a bit string. sorry.

By: Roger Klorese

Roger Klorese — Fri, 01 Aug 2008 15:08:26 +0000

OK, misconceptions in order:

1) XenServer supports six *active* NICs in release 4.1, and each active NIC can be an active/passive bond of two NICs. The number is increased in the current beta, codenamed “Project Orlando” — though i’m not sure what it will be by the ytime the software ships.

2) The Intel/AMD issue with live migration has nothing at all to do with paravirtualization — it has to do with direct execution passing through the CPU flags so CPU optimizations can be used. If affects all hypervisors. In some you can mask off some CPU flags — but once you’ve done this you’ve potentially traded off a lot of performance for the ability to migrate across platforms.

3) The new beta incorporates HA features, including the automated failover of the master to another node.

4) It also includes active/active teaming.

5) The NetApp integration is based on iSCSI, not NFS. But NFS servers — any NFS server — will deliver fast cloning and thin provisioning. The power of the NetApp adapter is thast it does it using the hardware capabilities.

By: Duncan

Duncan — Fri, 01 Aug 2008 04:45:03 +0000

Do they still only collect and save 15 minutes worth of performance data? that’s what really surprised me. And what also surprised me is that you could not choose which nic was used for Live Migration.