Comments on: Virtualization Short Take #15 http://blog.scottlowe.org/2008/07/31/virtualization-short-take-15/ The weblog of an IT pro specializing in virtualization, storage, and servers Thu, 11 Mar 2010 03:44:17 +0000 http://wordpress.org/?v=abc hourly 1 By: Andrew Miller http://blog.scottlowe.org/2008/07/31/virtualization-short-take-15/comment-page-1/#comment-40317 Andrew Miller Tue, 05 Aug 2008 02:38:30 +0000 http://blog.scottlowe.org/2008/07/31/virtualization-short-take-15/#comment-40317 I have actually had a reproducible crash (intermittent but definitely tied to vMotion) when I had a SUSE Linux VM with VMI enabled (both the right Linux kernel and enabled in the VM's settings) that got stuck in an "in-between" state between 2 ESX servers multiple times. Disabling VMI did the trick and it hasn't happened since (admittedly VMI support is pretty new). I have actually had a reproducible crash (intermittent but definitely tied to vMotion) when I had a SUSE Linux VM with VMI enabled (both the right Linux kernel and enabled in the VM’s settings) that got stuck in an “in-between” state between 2 ESX servers multiple times.

Disabling VMI did the trick and it hasn’t happened since (admittedly VMI support is pretty new).

]]> By: Demitasse http://blog.scottlowe.org/2008/07/31/virtualization-short-take-15/comment-page-1/#comment-40282 Demitasse Sun, 03 Aug 2008 09:30:26 +0000 http://blog.scottlowe.org/2008/07/31/virtualization-short-take-15/#comment-40282 I have had a student on a course who had an application that had a problem with being VMotioned. The application is a very realtime database application and uses UDP to communicate, it cannot cope with a single UDP packet being lost. As you can imagine the application doesn't like WAN connections either. It is clearly poorly written as UDP is connectionless and therefore has no guarantee of delivery, the application should expect to loose packets and should handle that gracefully. I have had a student on a course who had an application that had a problem with being VMotioned.
The application is a very realtime database application and uses UDP to communicate, it cannot cope with a single UDP packet being lost.
As you can imagine the application doesn’t like WAN connections either. It is clearly poorly written as UDP is connectionless and therefore has no guarantee of delivery, the application should expect to loose packets and should handle that gracefully.

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