Unable to poweron VMs due cpu slot size not availiable

[vmhyperv]

Hi,

Unable to power on the VMs getting error CPU slot size not avaliable.How to avoid the issue and resolve it.Kindly help. Please find the

screenshot.Right now no resourcepool configured.

[a_p_]

The issue you see seems to be caused by one or more VMs with memory and CPU reservations. HA uses the highest amount of reserved CPU and memory reservations for the slot size calculation. There are some unsupported settings to lower these values, however that's really not how the issue should be solve. The best solution would be to check if the VMs really need to have a reservation set and - if unnecessary - remove it. If you cannot remove the reservations, you could consider to change the HA Admission Control setting from the number of tolerated host failures to a value >25% (1 of 4 host can fail, assuming the hosts are eqaul). This may have impacts on HA restarts though for VMs with a high amount of configured memory or multiple CPUs.

André

[a_p_]

Discussion moved from VMware ESXi™ 4 to Availability: HA & FT

[S_Grimbuhler]

Hi

to check your slot size, (ha calculate the total ressource he has to reserve based on slot size) click on the cluster, summary tab, advanced runtime info (in the VMware HA box).

available slot will probably be to 0. check now your slot size, maybe you will see a big memory or / and cpu size (for HA this is what he musts reserve for each VM).

You can modify the slot size by reducing or removing VMs reservation (slot size are based on bigger reservation).

or you can modifiy advanced parameters to controle manually the size. it's fully supported by VMware and it's explained on the VMware ICM training.

parameters are das.slotCpuInMHz and/or das.slotMemInMB you can find an article on my blog : http://www.virtualgeek.ch/blog/2010/11/12/vmware-ha-slot-size/ (it's in french, but check the translator in the bottom :smileywink:)

hope it helps

Stéphane Grimbuhler

Senior Virtualization & Storage consultant (VCP / VCAP-DCA)

VMware Instructor (VCI)

My Blog : www.virtualgeek.ch

[Duncan Epping]

I would first recommend to read my HA deepdive: http://www.yellow-bricks.com/vmware-high-availability-deepdiv/

This will give you an understand of why this happens. You probably have a reservation set somewhere. I would recommend to use RVTools to identify the VM or VMs which skew the slotsize. Validate if this reservation is needed. Then remove it if it is not needed and the slotsize would go down. If you do require it I would suggest using the "percentage based" admission control policy instead as then you don't have to resort to advanced settings while maintaining flexibility.