VM CBT becomes disabled after a power cycle during scheduled maintenance
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VM CBT becomes disabled after a power cycle during scheduled maintenance

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Article ID: 409780

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Updated On:

Products

VMware vSphere ESXi 8.0

Issue/Introduction

VM CBT is disabled.
Backups fall back to full backups.
In vmware.log we see multiple entries in different form with respect to cleanshutdown as false

yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT              scsi0:0.redo = ""
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT                  vmci0.id = "464531068"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT             cleanShutdown = "FALSE"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT        scsi0:1.deviceType = "scsi-hardDisk"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT          scsi0:1.fileName = "VMNAME-000001.vmdk"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT      sched.scsi0:1.shares = "normal"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT sched.scsi0:1.throughputCap = "off"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT           scsi0:1.present = "TRUE"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT              scsi0:1.redo = ""
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT           config.readOnly = "FALSE"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT             uuid.location = "56 4d bc 62 f9 40 10 8c-9b 30 48 ca 74 0e 5c cb"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT                ctkEnabled = "TRUE"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT        scsi0:0.ctkEnabled = "TRUE"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT        scsi0:1.ctkEnabled = "TRUE"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT        scsi0:2.deviceType = "scsi-hardDisk"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT          scsi0:2.fileName = "VMDISK-000001.vmdk"
yyyy-mm-ddThh:mm:ss In(05) vmx me2i1fzi-69334-auto-1hhz-h5:70015287-99-04-01-81-fbf6 DICT        scsi0:2.ctkEnabled = "TRUE"

Another such entry is seen under ConfigDB, this being sequential to the above entry

yyyy-mm-ddThh:mm:ss In(05) vmx - OvhdMem: memsize 24576 MB VMK fixed 3349 pages var(mem) 529 pages var(cpu) 22 cbrcOverhead 0 pages total 16409 pages
yyyy-mm-ddThh:mm:ss In(05) vmx - VMMEM: Precise Reservation: 629MB (MainMem=24576MB) VMK=64MB
yyyy-mm-ddThh:mm:ss In(05) vmx - Vix: [mainDispatch.c:1051]: VMAutomation_PowerOn. Powering on.
yyyy-mm-ddThh:mm:ss In(05) vmx - VMX_PowerOn: ModuleTable_PowerOn = 1
yyyy-mm-ddThh:mm:ss No(00) vmx - ConfigDB: Setting cleanShutdown = "FALSE"
yyyy-mm-ddThh:mm:ss No(00) vmx - ConfigDB: Setting softPowerOff = "FALSE"

Once we power on VM we see below entries related to CBT

yyyy-mm-ddThh:mm:ss No(00) vmx 1061c8f-01-d6-f6b1 ConfigDB: Unsetting "ctkEnabled"
yyyy-mm-ddThh:mm:ss No(00) vmx 1061c8f-01-d6-f6b1 ConfigDB: Unsetting "scsi0:0.ctkEnabled"
yyyy-mm-ddThh:mm:ss No(00) vmx 1061c8f-01-d6-f6b1 ConfigDB: Unsetting "scsi0:1.ctkEnabled"
yyyy-mm-ddThh:mm:ss No(00) vmx 1061c8f-01-d6-f6b1 ConfigDB: Unsetting "scsi0:2.ctkEnabled"
yyyy-mm-ddThh:mm:ss No(00) vmx 1061c8f-01-d6-f6b1 ConfigDB: Unsetting "scsi0:3.ctkEnabled"





Environment

vSphere ESXI 7.x
vSphere ESXI 8.x

Cause

Existing CTK metadata was invalidated and wiped by the VMX following an unclean shutdown of the VM. Subsequently, the backup tool explicitly disabled CTK via API unsets, which prevented its reinitialization on new snapshots. Due to this lack of CTK history, later incremental backups were forced to fall back to full-data transfers. 

Resolution

Please make sure that the VM is gracefully shutdown

  1. Access the vSphere Client (if using vCenter) or the ESXi host's web interface directly.
  2. In the inventory pane, locate and select the virtual machine you wish to shut down. 
  3. Graceful Shutdown: Right-click the virtual machine and navigate to Power > Shut Down Guest OS. This initiates a clean shutdown from within the guest operating system. 
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