Since View 4.5 it is possible to use several settings to get more speed into the provisioning tasks of View Composer. Even if the changes speed up your VDI environment please bear in mind that manual changes in the ADAM are not supported.
Place Replica on SSD LUN
A new feature since 4.5 is the possibility to store Replica disk onto a different LUNs than the linked clones. Before 4.5 it was necessary to have one Replica per LUN. If the storage is fast enough, e.g. has a read optimized RAID Level and/or fast disks like SSD it can be a good option to boot all clones from one Replica. Be aware that this Replica is a single point of failure and must be secured on storage level.
The new option is available during the add pool wizard -> vCenter Settings -> Datastores. The Use different datastores for view composer replica disks checkbox must be activated. Afterwards it is possible to decide for which kind of data the storage is used.
Example: fcsan301_ds4 holds the replica disk, fcsan301_ds6 and fcsan301_ds8 are used for linked clones
Power on settings
Especially when creating linked clone pools with Sysprep or Quickprep the machines have to boot during the creation process. It is possible to send more concurrent power operations to the vCenter server to boot more machines at the same time. This setting can be modified via View Manager. Go to View Configuration -> Servers -> on the right side click your vCenter Server and edit.
Click the advanced button. It is possible to go up to 50 concurrent tasks.
Some people might notice the second option -max concurrent provisioning operations-, however this settings can be modified when using non linked clone pools to reduce the provisioning time, the View composer who is responsible for the creation of linked clones doesn’t benefit from this option.
To increase the concurrent cloning tasks triggered to View Composer it is necessary to edit the ADAM DB running on the View Manager server. To edit the ADAM DB you have to add ADSI Edit to your Management Console. See the following link for adding ADSI Edit. http://technet.microsoft.com/en-us/library/cc773354%28WS.10%29.aspx#BKMK_AddingADSIEdit
Once ADSI Edit is started connect to the local ADAM DB by using the following settings:
After connecting to the Database go to OU=Properties, OU=VirtualCenter. Open the properties of the CN value residing in OU=VirtualCenter.
Find the Attribute pae-SVICreationRampFactor. This value is not set to anything in which case it defaults to 2.
This factor controls the throttle of linked clone creation and deletion.
The maximum value of this factor is 50. If this value is set to be large than 50, the value 50 will be used. Adjust this number cautiously and not ramp it up to high right out of the box.
It is important to do a backup of the View Manager Server before making any changes. In order to edit the ADAM database this is a useful link: http://technet.microsoft.com/en-us/library/cc780496(WS.10).aspx
Before increasing all settings to max, monitor the Storage I/O and the CPU Usage of vCenter to find bottlenecks during creation. Raise the concurrent tasks in steps of ten.
The pae-SVICreationRampFactor attribute is used by initial creation tasks not when using recomposing. For reducing the recompose time there is no attribute in ADAM right now.
Please bear in mind that changes to the ADAM database are not supported.