ESXi Host fails to enter Maintenance Mode due to "No space left on the device" vMotion error

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

• When attempting to put an ESXi host into Maintenance Mode, the task fails or times out.
• Virtual machine migrations (vMotion) fail to initialize with the following error:
  A general system error occurred: Failed to create journal for Vmotion-SRC: Failed to open "/var/lib/vmware/hostd/journal/##########.####" for write: There is no space left on the device

Environment

• vCenter 8.x
• ESXi 8.x

Cause

The ESXi host's /var ramdisk has reached 100% capacity. The ESXi "Scratch" location is incorrectly pointed to a directory within the volatile /var ramdisk instead of a persistent datastore. When the ramdisk is full, the hostd service cannot create the mandatory journal headers required to start a vMotion migration, preventing the host from evacuating VMs and entering maintenance mode.

Resolution

Follow the steps below to identify and resolve the ramdisk space issue:

To allow the host to enter maintenance mode immediately, you must free up space on the ramdisk:

1. Log in to the ESXi host via SSH or the Direct Console User Interface (DCUI).
2. Verify the ramdisk usage:
   vdf -h
3. Identify and remove old compressed log files to reclaim space:
4. cd /var/log/vmware/
   mv *.gz <Persistant location>
5. Run the below command to validate the ramdisk usage:
   vdf -h
6. Once there is sufficient free space available in the ramdisk, vMotion the VMs to other hosts, allowing the ESXi host to be in maintenance mode.

Additional Information

To prevent recurrence, the scratch partition must be reconfigured from /var to a persistent datastore Creating a persistent scratch location for ESXi 8.x/7.x 
Investigate Ramdisk utilization Identifying and Resolving Full Ramdisk Issues in ESXi Environments 

vMotion エラー "No space left on the device" により ESXi ホストがメンテナンスモードへの移行に失敗する