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Table 5-7. Example Sizing Table for Linked-Clone Disks
Data Type
Selected Free Space
(GB)
Min Recommended
(GB) 50% Utilization (GB)
Max Recommended
(GB)
OS disks 184.23 40.00 80.00 130.00
Persistent disks 28.56 4.00 10.00 20.00
The Selected Free Space column shows the total available space on all of the datastores that you selected for
a disk type such as OS disks.
The Min Recommended column shows the minimum amount of recommended storage for a pool.
The 50% Utilization column shows the recommended storage when the linked-clone disks grow to 50% of the
parent virtual machine.
The Max Recommended column shows the recommended storage when the linked-clone disks approach the
full size of the parent virtual machine.
If you store OS disks and persistent disks on the same datastore, View Manager calculates the storage
requirements of both disk types. The Data Type is shown as Linked clones instead of a particular disk type.
If you store View Composer replicas on a separate datastore, the table also shows storage recommendations
for the replicas and adjusts the recommendations for OS disks.
Sizing Guidelines
The table provides general guidelines. Your storage calculations must account for additional factors that can
affect actual storage growth in the linked-clone pool.
For OS disks, your sizing estimates depend on how frequently you refresh and recompose the pool.
If you refresh your linked-clone pool between once a day and once a week, make sure that the Selected Free
Space can accommodate storage use between the Min Recommended and 50% Utilization estimates.
If you rarely refresh or recompose the pool, the linked-clone disks continue to grow. Make sure that the Selected
Free Space can accommodate storage use between the 50 % Utilization and Max Recommended estimates.
For persistent disks, your sizing estimates depend on the amount of Windows profile data that users generate
on their desktops. Refresh and recompose operations do not affect persistent disks.
How View Manager Calculates the Minimum Sizing Recommendations
To arrive at a minimum recommendation for OS disks, View Manager estimates that each clone consumes
twice its memory size when it is first created and started up. If no memory is reserved for a clone, an ESX swap
file is created for a clone as soon as it is powered on. The size of the guest operating system's paging file also
affects the growth of a clone's OS disk.
In the minimum recommendation for OS disks, View Manager 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 linked 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 Manager accounts
for two replicas that use the same space as the parent virtual machine.
To arrive at a minimum recommendation for persistent disks, View Manager calculates 20% of the disk size
that you specify on the View Composer Disks page of the Add 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 Manager calculates the
persistent disk size as 1GB. If you specify a disk size of 2048MB, View manager calculates the disk size as 2GB.
Chapter 5 Creating Desktop Pools
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