Disk is not eligiable to use for vSAN due to OSDATA partition on disk

Products

• VMware vSAN

Issue/Introduction

• Unable to claim a disk for vSAN.
  
  
• There is currently an existing VMFS partition on the disk:
  
  # partedUtil getptbl "/vmfs/devices/disks/naa.####"

gpt
97281 255 63 1562824368
7 16986112 268435455 4EB2EA3978554790A79EFAE495E21F8D vmfsl 0

• Unable to delete partition:
  
  # partedUtil delete "/vmfs/devices/disks/naa.#### 7"
  
  Error: Read-only file system during write on /dev/disks/naa.####
  Unable to delete partition 7 from device /vmfs/devices/disks/naa.####
  
  
  
• Attempts to wipe this disk dd fail:
  
  # dd if=/dev/zero of=/vmfs/devices/disks/naa.#### bs=1M count=50 conv=notrunc
  dd: writing '/vmfs/devices/disks/naa.####': Read-only file system

Environment

VMware vSphere ESXi 8.0.x

Cause

• ESXi was accidentally installed on a disk intended for vSAN.
  
  
• The esxcli storage filesystem list command shows an OSDATA-#### volume mounted on the problematic disk.
  
  
• After reinstalling ESXi elsewhere the OSDATA partition is still being utilized by this disk.
  
  
• In /var/run/log/vmkernel.log, you see: WARNING: Partition: ####: naa.####: in-use partition # modification is not supported.

Resolution

• Place Host in Maintenance Mode. Ensure no vSAN data is at risk.
  
  
• Deactivate Coredump File:
  List coredump files: esxcli system coredump file list
  Disable coredump: esxcli system coredump file set --enable false
  Remove coredump file: esxcli system coredump file remove --file #### (Replace #### with the file name found in the list).
  
  
• Redirect Scratch Location:
  Change the scratch location to a temporary or different persistent datastore: esxcli system syslog config set --logdir=/tmp/scratch
  
  
• Reboot the Host.
  
  
• Delete Partition: Attempt to wipe the disk again using partedUtil or dd conv=notrunc.
  
  
• If still unable to delete the partition then clear partition via host KVM.