Disk Usage of VM provisioned by Citrix MCS
Refer to the following finding on the Disk Usage of VM provisioned by Citrix MCS
Citrix Machine Creation Service (MCS) creates a snapshot of master the VM and it copies the full snapshot to the storage repository to serve as the master image (base disk).
When provisioning multiple virtual desktops or servers, MCS includes two types of disks: a differencing disk and an identity disk for each virtual machine.
Disk Usage of Master VM
We had provisioned an Master VM called CITRIX-MASTER-SRV with Windows 2019 Server Standard with latest patches and necessarily applications, like Google Chrome, Edge for Business and etc
Total disk size of the Master VM is 16GB (Thin Provisioned)
$VM = "CITRIX-MASTER-SRV"
#Check the Actual Size of VMDK file
(Get-VM -Name $VM).ExtensionData.LayoutEx.file | ? Name -like "*flat*" | Select Name, `
@{N="Size (GB)";E={[math]::Round(($_.size)/1GB)}}
Name Size (GB)
---- ---------
[LOCAL] CITRIX-MASTER-SRV/CITRIX-MASTER-SRV-flat.vmdk 16
Snapshot is created on Master VM
Get-VM $VM | Get-Snapshot | Select VM, Name
VM Name
-- ----
CITRIX-MASTER-SRV Citrix_XD_CITRIX-XenApp
Base Disk called CITRIX-XenApp-baseDisk-datastore-1012 is created
[root@nuc8:/vmfs/volumes/5e201eef-487a44db-35e0-54b2038b8296] ls -lh
total 1920
drwxr-xr-x 1 root root 72.0K Aug 22 15:39 CITRIX-MASTER-SRV
drwxr-xr-x 1 root root 72.0K Aug 22 15:41 CITRIX-XenApp-baseDisk-datastore-1012
[root@nuc8:/vmfs/volumes/5e201eef-487a44db-35e0-54b2038b8296/CITRIX-XenApp-baseDisk-datastore-1012] ls -lh
total 16517120
-rw------- 1 root root 100.0G Aug 22 15:41 CITRIX-XenApp-baseDisk-datastore-1012-flat.vmdk
-rw------- 1 root root 529 Aug 22 15:41 CITRIX-XenApp-baseDisk-datastore-1012.vmdk
[root@nuc8:/vmfs/volumes/5e201eef-487a44db-35e0-54b2038b8296/CITRIX-XenApp-baseDisk-datastore-1012] du -h
15.8G .
Disk Usage of VM provisioned by Citrix MCS
New VM called CITRIX-APP01 is provisioned by Citrix MCS from Master VM
The are 2 x Disks attached to CITRIX-APP01 – A differencing Disk and an Identity Disk
$VM = "CITRIX-APP01"
Get-VM $VM | Get-HardDisk | Select FileName, Persistence, CapacityGB
Filename Persistence CapacityGB
-------- ----------- ----------
[LOCAL] CITRIX-APP01/CITRIX-APP01-1509517a-3e24-4fb4-bfdd-e996f649beb1-xd-delta.vmdk IndependentNonPersistent 100
[LOCAL] CITRIX-APP01/CITRIX-APP01_IdentityDisk.vmdk Persistent 0.015625
The total size of CITRIX-APP01 is only 4.4GB
- 4GB swap file which is equal to the size of vRAM assigned
- Delta Disk only consumed 400MB when the VM is provisioned by Citrix MCS
[root@nuc8:/vmfs/volumes/5e201eef-487a44db-35e0-54b2038b8296/CITRIX-APP01] ls -lh
total 4663296
-rw------- 1 root root 4.0G Aug 22 15:48 CITRIX-APP01-1459a410.vswp
-rw------- 1 root root 407.0M Aug 22 15:41 CITRIX-APP01-1509517a-3e24-4fb4-bfdd-e996f649beb1-xd-delta-sesparse.vmdk
-rw------- 1 root root 538 Aug 22 15:41 CITRIX-APP01-1509517a-3e24-4fb4-bfdd-e996f649beb1-xd-delta.vmdk
-rw------- 1 root root 718.3M Aug 22 17:18 CITRIX-APP01-1509517a-3e24-4fb4-bfdd-e996f649beb1-xd-delta.vmdk-sesparse.REDO_365reu
-rw------- 1 root root 418 Aug 22 15:48 CITRIX-APP01-1509517a-3e24-4fb4-bfdd-e996f649beb1-xd-delta.vmdk.REDO_365reu
-rw-r--r-- 1 root root 245 Aug 22 15:41 CITRIX-APP01-5597dd92.hlog
-rw------- 1 root root 264.5K Aug 22 15:50 CITRIX-APP01.nvram
-rw-r--r-- 1 root root 180 Aug 22 15:41 CITRIX-APP01.vmsd
-rwxr-xr-x 1 root root 3.3K Aug 22 15:48 CITRIX-APP01.vmx
-rw------- 1 root root 0 Aug 22 15:48 CITRIX-APP01.vmx.lck
-rwxr-xr-x 1 root root 3.2K Aug 22 15:48 CITRIX-APP01.vmx~
-rw------- 1 root root 16.0M Aug 22 15:55 CITRIX-APP01_IdentityDisk-flat.vmdk
-rw------- 1 root root 560 Aug 22 15:48 CITRIX-APP01_IdentityDisk.vmdk
-rw-r--r-- 1 root root 187.5K Aug 22 17:18 vmware.log
-rw------- 1 root root 110.0M Aug 22 15:48 vmx-CITRIX-APP01-341419024-1.vswp
[root@nuc8:/vmfs/volumes/5e201eef-487a44db-35e0-54b2038b8296/CITRIX-APP01] du -h
4.4G .
Reference Links