Formula for Server Capacity Planning

[SamArun]

Hi All,

We are planning for the new ESXi 4.1 environment implementation from the current physical server to

We are planning for Virtualization from physical to Virtual machine, not a P2V but building it fresh systems. Formula used for Server Sizing on VM is:

• Min CPU Cycles needed for VM Server(MHz) = {CPU cycles used (MHz) * Growth factor * Failover factor}

                                                       Server(MHz) = {CPU cycles used MHz * 1.2 * 1}

• CPU cycles used  (MHz) = { Total MHZ * Peak CPU Utilization }

Same applies for Memory sizing.

Is the above mentioned formula satisfy the requirement. Else could any of you let me know the industry standard formula used for Server Sizing.

Regards,

Arun S

[J1mbo]

Can you give some info on the workloads being virtualised?

Usualy, CPU cycles are not the limiting factor but RAM and disk IOPs.  Also MHz to MHz comparisons would only be valid on the exact same CPU type.

[SamArun]

Physical Server & ESX Server configuration...

Hostname	RAM (GB)	Total Physical CPU Count	CPU Speed (GHz)	Total No of CPU Cores	Total MHZ	Avg CPU Utilization	Peak CPU Utilization	Peak Memory Utilization	cpu cycles   used  (MHz)
Servers	32	2	2.2	4	9011.2	42.00%	50%	80%	4505.6
Servers	32	2	2.2	4	9011.2	27.12%	50%	80%	4505.6
Servers	32	2	2.2	4	9011.2	25.00%	50%	80%	4505.6
Servers	32	2	2.2	4	9011.2	28.00%	50%	80%	4505.6
Servers	4	1	2.2	2	4505.6	30.50%	50%	80%	2252.8
Servers	12	2	2.6	1	2662.4	20.00%	50%	80%	1331.2
Servers	12	2	2.6	1	2662.4	12.00%	50%	80%	1331.2
Servers	36	4	2.53	16	41451.52	15.00%	50%	80%	20725.76
Servers	36	1	2.53	4	10362.88	13.00%	50%	80%	5181.44
VMware Cluster Farm
ESX Server Name	Server Model	sockets	cpus	core per	cores	speed	RAM	OS	Total CPU   MHz
				cpu		(MHz)	(GB)
ESX Servers	IBM HX5 MAX 5	2	2	8	16	2266	256	VMware	36256
ESX Servers	IBM HX5 MAX 5	2	2	8	16	2266	256	VMware	36256
ESX Servers	IBM HX5 MAX 5	2	2	8	16	2266	256	VMware	36256
ESX Servers	IBM HX5 MAX 5	2	2	8	16	2266	256	VMware	36256
								Total	145024

The above 2 table shows the Physical Server usage & VMware Cluster (Proposed Configuration).

[J1mbo]

Need to know what CPUs the old and new boxes have.  Why are all the RAM utilisations exactly 80%?