Symptoms
Content-Based Read Cache(CBRC) is disabled in the entire environment:
CBRC can be disabled on the vSphere at the ESXi Host advanced settings ( "CBRC.Enable" to "false" and "CBRC.DCacheMemReserved" to 0").In Horizon Administrator it can be disabled through Horizon Admin Console > Settings > Servers > vCenter Servers tab, and click Edit on vCenter. Under the Storage Tab, uncheck "Enable View Storage Accelerator" and Save the settings. After disabling CBRC, the instant clone pool's provisioning tasks would still perform CBRC actions ( Digest Operation) on vCenterOnce CBRC is disabled in Horizon, existing instant clones do not reflect the change and still perform Disk Digest Operations which results in Provisioning Failures Some vMotions of such VDIs on the vCenter might fail due to timeouts
Purpose
This article explains how to disable CBRC on existing Instant Clone Pools that were created with CBRC enabled in the environment.
Cause
The digest disks would still be pre-configured on internal cp-replica VMs because Storage Acceleration was enabled when the pool was created.
Resolution
Procedure to disable the CBRC on existing Instant Clone Pools:
Take a backup of the ADAM database Performing an end-to-end backup and restore for VMware Horizon View Please take a snapshot of all connection servers (unchecking the memory option) along with a backup of the ADAM database prior to making DB changes
Note: After the parameter has changed, please ensure that a new snapshot is taken on all impacted pools and rolled out
* Now you can update the pae-CBRCEnable parameter by following any one of the following options.
===========================Option 1: [ Through ADSI Edit ] ===========================1. Connect to the ADAM database on a Connection Server: Connecting to the Horizon View Local ADAM Database2. Drop down dc=vdi,dc=vmware,dc=int and navigate to OU=Server Groups.3. Right Click the desired pool (CN=PoolName) > Properties4. Double click the pae-CBRCEnable parameter, change that to 0 and click OK to save the change.5. Once this has been done, take a new snapshot of the golden image, and push them out to the pool.===========================Option 2: [ Through PowerCli ]===========================1. On the Connection Server, please open Powershell as Horizon Administrator User.2. Run the following command: Set-ADObject -Server localhost:389 'CN=<poolname>,OU=Server Groups,dc=vdi,dc=vmware,dc=int' -Replace @{'pae-CBRCEnable'="0"}3. Once this has been done, take a new snapshot of the golden image, and push them out to the pool.Note: Replace the bold word "poolname" with the actual pool name on the command above.
* With this new snapshot, the internal cp-replica VMs are recreated without the CBRC flag.
