Minimum H/W requirement for VMware vCenter server 4.x and 5.x

VMware vCenter Server 4.x

Hardware	Requirement
Processor	Intel or AMD x86 (64-bit if installing vCenter Server 4.1) processor with two or more logical cores, each with a speed of 2GHz.
Memory	3GB RAM. RAM requirements may be higher if your database runs on the same machine. VMware VirtualCenter Management WebServices requires 128Mb to 1.5GB of memory which is allocated at startup.
Disk storage	2GB. Disk requirements may be higher if your database runs on the same machine. Microsoft SQL Server 2005 Express requires up to 2GB free disk space to decompress the installation archive.
Networking	1Gbit recommended

VMware vCenter Server 5.x

vSphere 5.1 introduced the vCenter Single Sign-On (SSO) component as part of the vCenter Server management infrastructure. This change affects vCenter Server installation. Authentication by vCenter Single Sign-On makes the VMware cloud infrastructure platform more secure by allowing the vSphere software components to communicate with each other through a secure token exchange mechanism.


Let us see the different parameters required for the installation of VMware vCenter Server

Minimum hardware requirements for vCenter Server

Hardware	Requirement
CPU	Two 64-bit CPUs or one 64-bit dual-core processor.
Processor	2.0GHz or faster Intel 64 or AMD 64 processor. Processor requirements might be higher if the database runs on the same machine. NOTE: The Itanium (IA64) processor is not supported.
Memory	The amount of memory needed depends on your vCenter Server configuration. If vCenter Server is installed on a different host machine than vCenter Single Sign On and vCenter Inventory Service, 4GB of RAM are required. If vCenter Server, vCenter Single Sign On and vCenter Inventory Service are installed on the same host machine (as with vCenter Simple Install), 10GB of RAM are required. NOTE: Memory requirements are higher if the vCenter Server database or vCenter Single Sign On database runs on the same machine as vCenter Server.
Disk storage	The amount of disk storage needed for the vCenter Server installation depends on your vCenter Server configuration. If vCenter Server is installed on a different host machine than vCenter Single Sign On and vCenter Inventory Service, 4GB are required. If vCenter Server, SSO, and vCenter Inventory Service are installed on the same host machine (as with vCenter Simple Install), at least 40-60GB of free disk space are required after installation, depending on the size of your inventory. 100GBare recommended, to allow for future growth of your inventory.
Microsoft SQL Server 2008 R2 Express disk	Up to 2GB free disk space to decompress the installation archive. Approximately 1.5GB of these files are deleted after the installation is complete.
Network speed	1Gbit connection recommended.

System recommendations for performance based on deployment size

Medium deployment of up to 50 hosts and 500 powered-on virtual machines

Product	Cores	Memory	Disk
vCenter Server	2	4GB	5GB

Large deployment of up to 300 hosts and 3,000 powered-on virtual machines

Product	Cores	Memory	Disk
vCenter Server	4	8GB	10GB

Extra-large deployment of up to 1,000 hosts and 10,000 powered-on virtual machines

Product	Cores	Memory	Disk
vCenter Server	8	16GB	10GB

Hardware requirements for vSphere Web Client server component

Hardware	Requirement
Memory	At least 2GB. of which 1GB is for the Java heap and 1GB for The resident code The stack for Java threads Global/bss segments for the Java process
CPU	2.00 GHz processor with at least 2 or more cores
Disk storage	At least 2GB free disk space
Networking	1Gbit recommended

Hardware requirements for VMware vCenter Server Appliance

Hardware	Requirement
Disk storage on the host machine	The vCenter Server Appliance requires at least 7GB of disk space, and is limited to a maximum size of 80GB. The vCenter Server Appliance can be deployed with thin-provisioned virtual disks that can grow to the maximum size of 80GB. NOTE: If the host machine does not have enough free disk space to accommodate the growth of the vCenter Server Appliance virtual disks, vCenter Server might cease operation, and you will not be able to manage your vSphere environment.
Memory in the VMware vCenter Server Appliance	Very small inventory (10 or fewer hosts, 100 or fewer vms): at least 4GB. Small inventory (10-100 hosts or 100-1000 virtual machines): at least 8GB. Medium inventory (100-400 hosts or 1000-4000 virtual machines): at least 16GB. Large inventory (More than 400 hosts or 4000 virtual machines): at least 24GB.

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Configuration Maximum comparison for VMware vSphere 5.0, 5.1 and 5.5

Here I have summarized the comparison with a list of selected features between vSphere ESXi 5.0, 5.1 and5.5. I have skipped some of the features for detailed overview on all the comparison factors please visit vmware's official website.


ESXi Virtual Machine Maximum

Items	Maximum
	vSphere 5.0	vSphere 5.1	vSphere 5.5
Virtual CPUs per virtual machine	32	64	64
RAM per virtual machine	1 TB	1 TB	1 TB
Virtual SCSI targets per virtual machine	60	60	60
Virtual Disks per virtual machine	60	60	60
Virtual NIC per virtual machine	10	10	10
Concurrent remote console connection per virtual machine	40	40	40
Virtual disk size	2 TB	2 TB	62 TB
Video memory per virtual machine	128 MB	128 MB	512 MB

ESXi Host maximum

Items	Maximum
	vSphere 5.0	vSphere 5.1	vSphere 5.5
Logical CPUs per host	160	160	320
Virtual machine per host	512	512	512
Virtual CPUS per host	2048	2048	4096
Virtual CPUs per core	25	25	32
FT Virtual Disks	16	16	16
RAM per FT virtual machine	64	64	64
FT virtual machine per host	4	4	4
FT virtual CPUs per virtual machine	1	1	1

Memory Maximum

Items	Maximum
	vSphere 5.0	vSphere 5.1	vSphere 5.5
RAM per host	2 TB	2 TB	4 TB
No of swap files per virtual machine	1	1	1
Swap file size	1 TB	1 TB	NA

Storage Maximum

Items	Maximum
	vSphere 5.0	vSphere 5.1	vSphere 5.5
Virtual Disks per host	2048	2048	2048
LUNs per server	256	256	256
Broadcom 1Gb iSCSI HBA initiator ports per server	4	4	4
Broadcom 10Gb iSCSI HBA initiator ports per server	4	4	4
No. of total paths on a server	1024	1024	1024
No. of paths to a LUN	8	8	8
Software iSCSI targets	256	256	256
LUNs per host	256	256	256
LUN size	NA	64 TB	64 TB
No. of paths to a LUN	32	32	32
No. of total paths on a server	1024	1024	1024
No. of HBAs of any type	8	8	8
HBA ports	16	16	16
Targets per HBA	256	256	256
Concurrent vMotion operations per datastore	128	128	128
Concurrent storage vMotion operations per datastore	8	8	8
Concurrent storage vMotion operations per host	2	2	2
Concurrent vMotion operations per host (1Gb/s network)	4	4	4
Concurrent vMotion operations per host (10Gb/s network)	8	8	8

Cluster and resource pool maximums

Items	Maximum
	vSphere 5.0	vSphere 5.1	vSphere 5.5
Hosts per cluster	32	32	32
Virtual machine per cluster	3000	4000	4000
Virtual machines per host	512	512	512
Resource pools per host	1600	1600	1600
Children per resource pool	1024	1024	1024
Resource pools per cluster	1600	1600	1600

vCenter Server maximums

Items	Maximum
	vSphere 5.0	vSphere 5.1	vSphere 5.5
Hosts per vCenter Server	1000	1000	1000
Powered‐on virtual machines per vCenter Server	10000	10000	10000
Registered virtual machines per vCenter Server	1500	1500	1500
Linked vCenter Servers	10	10	10
Hosts in linked vCenter Servers	3000	3000	3000
Concurrent vSphere Client connections to vCenter Server	100	100	100
Number of host per datacentre	500	500	500
Registered virtual machines in linked vCenter Servers	50000	50000	50000

Storage DRS

Items	Maximum
	vSphere 5.0	vSphere 5.1	vSphere 5.5
Virtual disks per datastore cluster	9000	9000	9000
Datastores per datastore cluster	32	32	32
Datastore clusters per vCenter	256	256	256

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