Symptoms
Symptom 1: The root for the Ramdisk is at 100% Use%.
Use putty to ssh to the ESXi host.
vdf -h
Verify root shows 100%.
Example of output:
Root shows Use% 100%.
Symptom 2: The root for the ramdisk is full, and the following error shows when running:
esxcli software vib list
You see an error ending with "socket.error: [Errno 2] No such file or directory"ORLog files are missing or not being updated in /var/log/.ORYou cannot install HA agent on the affected ESXi host.
Cause
Two possible causes:
1. Files were manually copied to a host and the incorrect path (that is, one outside /vmfs/volumes) was used.
2. If a persistent scratch space is not available, ESXi stores this temporary data on a ramdisk. This is constrained in space. This may be problematic in low-memory situations but is not critical to the operation of ESXi. Information that is stored on a ramdisk does not persist across reboots, so troubleshooting information such as logs and core files could be lost. If the host's persistent scratch location is configured improperly, intermittent issues may occur due to insufficient space for temporary files and log files not updating.
Resolution
1. For file issues, review VMware KB: RAM disk is full (2001550) (vmware.com) and follow the steps below.
If an administrative action caused the error, delete the files that use the incorrect path or move them to a datastore.
OR
Use putty to ssh to the ESXi host.
find / -size +1024k -exec du -h {} \; | less
Move or delete any old or stale left over ESXi host log bundles.
2. To resolve this issue, review VMware KB: https://kb.vmware.com/s/article/1033696 and follow the steps below.
Use putty to ssh to the ESXi host.
df -h
Annotate the file path for the 'Filesystem' "VMFS-L", which shows under 'Mounted on'. NOTE: This is a symbolic link that goes to the directory which is the volume WITHOUT 'OSDATA-' at the beginning. As an example, using the information from the screenshot above, the file path VMFS-L is 'Mounted on' shows as '/vmfs/volumes/OSDATA-604f7166-b35be91f-0d4c-005056281a17'.Log in to vCenter.Click the host in question.Go to Configure > System > Advanced System Settings.Filter the Key for 'scratchconfig'.Look for 'ScratchConfig.ConfiguredScratchLocation'.Insert the file path from step 3 without "OSDATA-." As an example: '/vmfs/volumes/OSDATA-604f7166-b35be91f-0d4c-005056281a17' should be entered as '/vmfs/volumes/604f7166-b35be91f-0d4c-005056281a17'.Put the host into Maintenance Mode, and restart the host.When the host restarts, log in to vCenter to verify 'ScratchConfig.ConfiguredScratchLocation' AND 'ScratchConfig.CurrentScratchLocation' are showing the correct directory path added in step 9.
