ESXi Ramdisk /tmp is 100% full

Products

• VMware vSphere ESXi
• VMware vSphere ESXi 8.0

Issue/Introduction

vMotion fails, HA agents stop responding, lose the ability to log into the Host Client.

vmkwarning.log

YYYY-MM-DDTHH:MM:SS cpu33:5780096)WARNING: VisorFSRam: 203: Cannot extend visorfs file /tmp/vmware.log because its ramdisk (tmp) is full.
YYYY-MM-DDTHH:MM:SS cpu25:2101483 opID=51031a58)WARNING: VisorFSRam: 203: Cannot extend visorfs file /tmp/.CacheConfig.lock.LOCK.2100362 because its ramdisk (tmp) is full.

Environment

VMware vSphere ESXi

Cause

Since ramdisks live in the system memory, this is usually caused by runaway log files, files copied and forgotten there, leftover patch files, or a third-party agent (like backup or monitoring tools)

 

Resolution

Check what the /tmp folder was filled with, the largest file will give the Root Cause

1. Verify the space

vdf -h

Find the largest files

ls -lSh /tmp | head -n 20

cd /tmp

ls -l

2. A reboot of the ESXi will temporarily solve the issue