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Objective 4.1 – Install vCenter Server |
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Written by Matthijs van den Berg
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Thursday, 15 October 2009 22:13 |
Knowledge
- Identify hardware requirements
The hardware requirements for a vCenter Server depend on the number of ESX hosts and Virtual Machines you plan to deploy in that environment. VMware has made some estimation on the hardware requirements based on the number of VMs and ESX host:
- Up to 200 ESX hosts a 32 bit can be sufficient, however a 64 bit server is always recommended. Above 200 ESX hosts a 64 bit server is required.
- The MINIMUM requirements (thank you ITTamer!) are (can be more when the DB is on the same machine):
- 2 x 2Ghz CPU
- 3 GB RAM
- 2 GB Disk
- The recommended setting for up to 50 ESX hosts and 250 VMs are:
- 2 CPUs
- 4 GB RAM
- 3GB Disk Space
- The recommended setting for up to 200 hosts and 2000 VMs are:
- 4 CPUs
- 4 GB RAM
- 3GB Disk Space
- The recommended setting for up to 300 hosts and 3000 VMs are:
- 4 CPUs
- 8 GB RAM
- 3GB Disk Space
- Understand configuration maximums
As most of you know the vSphere environment can handle a lot, but there are maximums. VMware stated those maximums in a document that you can find here.
This document states all the configuration maximums in regards to ESX hosts, VMs, resource pools, etc. Because the is the vCenter chapter I have summarized some of the vCenter maximums:
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Item
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Max.
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ESX hosts on 32 bit vSphere
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200
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VMs on 32 bit vSphere (powered on / registered)
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2000 / 3000
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ESX hosts on 64 bit vSphere
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300
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VMs on 64 bit vSphere (powered on / registered)
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3000 / 4500
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Linked vCenters
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10
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Concurrent vSphere Clients (32 / 64 bit)
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15 / 30
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ESX hosts / datacenter
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100
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Concurrent (storage) VMotions (Host / Datastore)
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2 / 4
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Concurrent operations per vCenter
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96
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Read more about the configuration maximums of vCenter here on page 6.
- Determine availability requirements for a vCenter server in a given situation
VMware vCenter is the hard of the Virtual infrastructure. Despite the fact that you infrastructure can run without a VC for a while it is best for management and features like DRS to have a vCenter. I have thought about this for a number of scenario’s:
- One site, limited number of hosts
When you run vCenter on one host with a limited number of ESX hosts and limited up-time demands you can install the vCenter Server in a VM. Enabling HA on you cluster will increase the availability of the vCenter Server in case of a ESX host crash.
- One site, more host and high available demands
When the demands for availability are higher of DRS must almost always work you can increase the availability of a vCenter by running it:
- In a MSCS environment (not officially supported?)
- In vCenter Linked mode
- By enabling “Fault Tolerance” for the VM
- vCenter on more than one site
When you have more than one site you best run vCenter in linked mode. This ensures not only that the service is running on two sites but also that the configuration is replicated.
- Determine appropriate vCenter Server edition
vCenter comes in different flavors.
- VMware vCenter Server Standard.
Provides large scale management of vSphere deployments for rapid provisioning, monitoring, orchestration and control of virtual machines.
- VMware vCenter Server Foundation.
Provides powerful management tools for smaller environments (up to three vSphere hosts) looking to rapidly provision, monitor and control virtual machines.
- VMware vCenter Server for Essentials.
Integrated into the vSphere Essentials and Essentials Plus editions for small office deployments.
- Determine database size requirements
The size of the vCenter database is mainly determined by the amount of performance statistics collected. This is a settings that you can set. In the past VMware delivered a excel sheet to calculate the estimated MS SQL Server database size but in the new vSphere version this is being calculated in realtime in the GUI. To change this setting and see the DB size estimate:
- Goto the menu item “Administration”, “vCenter Server Settings”
- Click “Statistics”
- Choose a interval duration and click “Edit”
- When the interval in selected the DB size is shown. When you click edit you can change the level. There are four levels in where level 1 is the lowest level and level 4 is the highest level logging nearly anything on the system. When is change the five minute interval from log level 1 to four the DB size estimate goes from 15 GB to roughly 44 GB! Wow! And I did not even change the save period from the default of one day.
- Prepare/Configure vCenter Server database
How to prepare your database highly depends on your installation. VMware recommends a separate database for the vCenter Server and for the vCenter Update Manager. Each vCenter Server must have it own database, however those database can be on the same SQL Server (if that is the best approach…I don’t know, but don’t think so). Read here, chapter 10, to see what database you would like to use etc.
- Install vCenter Server using downloaded installer
VMware allows you to download the vCenter installation media as a EXE file of as an ISO file. The ISO file can be mounted or burned to DVD, the EXE file can run directly on a OS but has to be copied there. Read more here on page 83.
- Install additional modules
VMware allows fro plug-ins into the vCenter client. These are both VMware as third party supplied and add extra functionality. To install plug-ins:
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- Select “Plug-ins”, “Manage Plug-ins..” from the vCenter client menu
- Install plug-ins to your needs
- vCenter Guided Consolidation
The Guided Consolidation plug-in is the P2V plug-in. It allows you to select physical servers and convert them using a wizard to a virtual machine. This plug-ins has to be installed explicitly. The installer is in the Virtual Center installation media and you can select this during the installation wizard. Read more here on page 103.
- vCenter Update Manager
The Update Manager allows you to update you infrastructure, including updates to third party guest operating systems. The plug-in is available if the Update Manager is installed.
- vCenter Converter
The Converter allows you to convert existing VM Backups, VMs and physical machines to a virtual server. You have to download and install the converter.
- Determine use case for vCenter Linked Mode Groups
VMware vCenter linked mode allows you to link vCenter installations. Reasons to do so can be:
- Availability
When you link vCenter servers those servers can manage the entire infrastructure. When one server fails, for example on site A, you can connect to the linked server on site B to continue working.
- Configuration maximums
The number of ESX hosts, VMs and users per vCenter server is limited. When running into those limits adding additional vCenter servers can increase those configuration maximums. The number of ESX hosts can grow up to a 1000 and the number of powered on VM can be 10.000! You can link a maximum of 10 vCenter servers.
Tools
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