7.0

In the minimum recommendation for OS disks, View also includes space for two replicas on each datastore.
View Composer creates one replica when a pool is created. When the pool is recomposed for the first time,
View Composer creates a second replica on the datastore, anchors the clones to the new replica, and deletes
the first replica if no other clones are using original snapshot. The datastore must have the capacity to store
two replicas during the recompose operation.
By default, replicas use vSphere thin provisioning, but to keep the guidelines simple, View accounts for two
replicas that use the same space as the parent virtual machine.
To arrive at a minimum recommendation for persistent disks, View calculates 20% of the disk size that you
specify on the View Composer Disks page of the Add Desktop Pool wizard.
NOTE The calculations for persistent disks are based on static threshold values, in gigabytes. For example, if
you specify a persistent disk size of any value between 1024MB and 2047MB, View calculates the persistent
disk size as 1GB. If you specify a disk size of 2048MB, View calculates the disk size as 2GB.
To arrive at a recommendation for storing replicas on a separate datastore, View allows space for two
replicas on the datastore. The same value is calculated for minimum and maximum usage.
For details, see “Sizing Formulas for Instant-Clone and Linked-Clone Pools,” on page 243.
Sizing Guidelines and Storage Overcommit for View Composer Linked Clones
NOTE Instant clones do not support storage overcommit.
After you estimate storage requirements, select datastores, and deploy the pool, View provisions linked-
clone virtual machines on different datastores based on the free space and the existing clones on each
datastore.
Based on the storage-overcommit option that you select on the Select Linked Clone Datastores page in the
Add Desktop Pool wizard, View stops provisioning new clones and reserves free space for the existing
clones. This behavior ensures that a growth buffer exists for each machine in the datastore.
If you select an aggressive storage-overcommit level, the estimated storage requirements might exceed the
capacity shown in the Selected Free Space column. The storage-overcommit level affects how many virtual
machines that View actually creates on a datastore.
For details, see “Set the Storage Overcommit Level for Linked-Clone Virtual Machines,” on page 246.
Sizing Formulas for Instant-Clone and Linked-Clone Pools
Storage-sizing formulas can help you estimate how much disk space is required on the datastores that you
select for OS disks, View Composer persistent disks, and replicas.
NOTE The persistent disk information is for View Composer linked clones only. Instant clones do not
support persistent disks.
Storage Sizing Formulas
Table 16-2 shows the formulas that calculate the estimated sizes of the disks when you create a pool and as
the clones grow over time. These formulas include the space for replica disks that are stored with the clones
on the datastore.
If you edit an existing pool or store replicas on a separate datastore, View uses a different sizing formula.
See “Sizing Formulas for Creating Clones When You Edit a Pool or Store Replicas on a Separate Datastore,”
on page 244.
Chapter 16 Reducing and Managing Storage Requirements
VMware, Inc. 243