Comments on: VMware engineers caution IT pros: Use Fault Tolerance sparingly http://itknowledgeexchange.techtarget.com/server-virtualization/vmware-engineers-caution-it-pros-use-fault-tolerance-sparingly/ A SearchServerVirtualization.com blog Sun, 29 Nov 2009 12:12:27 +0000 http://wordpress.org/?v=2.6.2 By: MikeLaverick http://itknowledgeexchange.techtarget.com/server-virtualization/vmware-engineers-caution-it-pros-use-fault-tolerance-sparingly/#comment-1588 MikeLaverick Thu, 14 May 2009 15:43:18 +0000 http://itknowledgeexchange.techtarget.com/server-virtualization/?p=1430#comment-1588 I'm suprised they set the value so high. Private-beta webcasts put the value more around the 10% mark. I don't think at the end of the day the overhead is perhaps the most significant limitation on FT to date. Most customers accept you don't get something for nothing when it comes to feature like VMotion, SVMotion and FT. What will make FT tricky - is two things - the conversion of the virtual disks they already have to zeroedthick to eagerzeroedthick. The fact that FT only supports 1-vCPU when many critical systems that would suit FT are using vSMP. And last the bandwidth required for the FT Logging network - in addition to their VMotion pipes..... The message is the product. Enable HA it protect ALL VMs in the cluster, but FT is enabled on per-VM basis... I’m suprised they set the value so high. Private-beta webcasts put the value more around the 10% mark. I don’t think at the end of the day the overhead is perhaps the most significant limitation on FT to date. Most customers accept you don’t get something for nothing when it comes to feature like VMotion, SVMotion and FT.

What will make FT tricky - is two things - the conversion of the virtual disks they already have to zeroedthick to eagerzeroedthick. The fact that FT only supports 1-vCPU when many critical systems that would suit FT are using vSMP. And last the bandwidth required for the FT Logging network - in addition to their VMotion pipes…..

The message is the product. Enable HA it protect ALL VMs in the cluster, but FT is enabled on per-VM basis…

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