View Composer can generate and preserve local computer security identifiers (SIDs) for linked-clone virtual machines in some situations. View Composer can preserve globally unique identifiers (GUIDs) of third-party applications, depending on the way that the applications generate GUIDs.
To understand how View Composer operations affect SIDs and application GUIDs, you should understand how linked-clone machines are created and provisioned:
- View Composer creates a linked clone by taking these actions:
- Creates the replica by cloning the parent virtual-machine snapshot.
- Creates the linked clone to refer to the replica as its parent disk.
- View Composer and View customize the linked clone with QuickPrep or a Sysprep customization specification, depending on which customization tool you select when you create the pool.
- If you use Sysprep, a unique SID is generated for each clone.
- If you use QuickPrep, no new SID is generated. The parent virtual machine's SID is replicated on all provisioned linked-clone machines in the pool.
- Some applications generate a GUID during customization.
- View creates a snapshot of the linked clone.
The snapshot contains the unique SID generated with Sysprep or common SID generated with QuickPrep.
- View powers on the machine according to the settings you select when you create the pool.
Some applications generate a GUID the first time the machine is powered on.
For a comparison of QuickPrep and Sysprep customization, see Choosing QuickPrep or Sysprep to Customize Linked-Clone Machines.
When you refresh the linked clone, View Composer uses the snapshot to restore the clone to its initial state. Its SID is preserved.
If you use QuickPrep, when you recompose the linked clone, the parent virtual machine's SID is preserved on the linked clone as long as you select the same parent virtual machine for the recompose operation. If you select a different parent virtual machine for the recomposition, the new parent's SID is replicated on the clone.
If you use Sysprep, a new SID is always generated on the clone. For details, see Recomposing Linked Clones Customized with Sysprep.
Table 1 shows the effect of View Composer operations on linked-clone SIDs and third-party application GUIDs.
|Support for SIDs or GUIDs||Clone Creation||Refresh||Recompose|
|Sysprep: Unique SIDs for linked clones||With Sysprep customization, unique SIDs are generated for linked clones.||Unique SIDs are preserved.||Unique SIDS are not preserved.|
|QuickPrep: Common SIDs for linked clones||With QuickPrep customization, a common SID is generated for all clones in a pool.||Common SID is preserved.||Common SID is preserved.|
|Third-party application GUIDs||Each application behaves differently.
Note: Sysprep and QuickPrep have the same effect on GUID preservation.
|The GUID is preserved if an application generates the GUID before the initial snapshot is taken.
The GUID is not preserved if an application generates the GUID after the initial snapshot is taken.
|Recompose operations do not preserve an application GUID unless the application writes the GUID on the drive specified as a View Composer persistent disk.|