Quick Tip - Using ESXCLI to upgrade ESXi 8.x throws MemoryError or Got no data from process

Several users in the community have reported running into a memory error issue when attempting to upgrade their standalone ESXi hosts using this ESXCLI trick, which has been possible since ESXi 5.1 back in 2012.

[MemoryError]
Please refer to the log file for more details.

Initially, I was not able to reproduce in my lab environment at work, which was running ESXi 8.0 Update 2, but I still got an error message but it was different:

Got no data from process.
Command "LANG=en_US.UTF-8 /usr/lib/vmware/esxcli-software sources.profile.list -d "https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml" "
еxited with error code: 1

After checking my homelab environment which was also running ESXi 8.0 Update 2, I did see the same MemoryError message as reported by the community when using ESXCLI to list the available ESXi Image Profiles from VMware's online patch repository.

I was about to report this ESXCLI issue when I saw that an internal PR had already been filed and Engineering is currently investigating the problem, which I have also asked for a KB to be published for awareness and resolution tracking purposes.

From the preliminary assessment, the issue is due to the fixed amount of memory (300MB) that is assigned to the ESXCLI process when it runs and because the VMware's online patch repository has gotten bigger with each release, additional memory is required to parse the current repository, which exceeds the fixed limit. You can see this limi by running: grep 'mem=' /usr/lib/vmware/esxcli-software

The fixed memory limit for ESXCLI was only introduced in ESXi 8.x and is not observed in ESXi 7.x, which would also explain why I was not seeing this problem when using the latest ESXi 7.0 Update 3 host.

The current guidance for this problem is to either update/upgrade using vCenter Server OR if you have a standalone ESXi host, point ESXCLI to a local ESXi offline bundle ZIP file rather than using the online VMware patch repository which would avoid parsing the repo's metadata. The other nice benefit of using the local patch method is that you only have to download the update once rather than pulling it down multiple times if you have more than a single ESXi host to update.

Alternatively, if this is just your homelab and you only have a single ESXi host like myself, there is a workaround that I was able to figure out that would allow you to still use online VMware patch repository but this is is definitely not officially supported.

Login to the ESXi Shell via SSH and run the following command, which will update the configured ESXCLI memory limit from 300MB to 500MB, which should be sufficient to now use ESXCLI to update/upgrade your ESXi host:

esxcli system settings advanced set -o /VisorFS/VisorFSPristineTardisk -i 0
cp /usr/lib/vmware/esxcli-software /usr/lib/vmware/esxcli-software.bak
sed -i 's/mem=300/mem=500/g' /usr/lib/vmware/esxcli-software.bak
mv /usr/lib/vmware/esxcli-software.bak /usr/lib/vmware/esxcli-software -f
esxcli system settings advanced set -o /VisorFS/VisorFSPristineTardisk -i 1