Symptoms
Extending a virtual disk fails.The VMware vSphere Client displays the error: Hot-extend is currently supported only for VMFS flat virtual disks without snapshots opened in persistent mode. The disk extend operation failed: msg.disklib.UNSUPPORTEDFEATURE
In the /vmfs/volumes/VM_Directory/vmware.log file of the affected virtual machine, there are entries similar to: <YYYY-MM-DD>T<time> 015Z| vmx| I120: HotExtend: Extending scsi1:0 to 167772160 <YYYY-MM-DD>T<time> 025Z| vmx| I120: Msg_Post: Error <YYYY-MM-DD>T<time> 025Z| vmx| I120: [msg.disk.hotextend.Failed] Failed to extend disk scsi1:0. </time></time></time>Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment. Extending the virtual disk fails regardless of the virtual machine's power state.
Purpose
This article provides steps to edit the descriptor file (vm.vmdk) of the failing base disk and modify the PID to ffffffff.
Cause
This issue occurs when the ParentCID of the base disk is not set to ffffffff.For example:
# Disk DescriptorFile
version=3
encoding="UTF-8"
CID=27eaf453
parentCID=72ca12de
isNativeSnapshot="no"
createType="vmfs"
Resolution
To resolve this issue, edit the descriptor file (vm.vmdk) of the failing base disk and modify the PID to ffffffff.To edit the descriptor (vm.vmdk) file:
Note: Ensure to take a backup of the virtual machine before proceeding with these steps.
Log in as root to the ESXi host through SSH.Modify the descriptor (vm.vmdk) file by running this command: vi /vmfs/volumes/datastore/VM_Directory/vm.vmdk For more information, see Editing files on an ESX host using vi or nano (1020302). For example: # Disk DescriptorFile version=3 encoding="UTF-8" CID=27eaf453 parentCID=ffffffff isNativeSnapshot="no" createType="vmfs" Save and close the file.
Related Information
Recreating a missing virtual machine disk descriptor file仮想ディスクの拡張が次のエラーで失敗する： msg.disklib.UNSUPPORTEDFEATURE扩展虚拟磁盘失败并显示错误：msg.disklib.UNSUPPORTEDFEATURE
