I have been working with couple of vSphere 6.5 upgrades and I experienced this issue while I was upgrading Dell R630 Host in to ESXi 6.5. Host was not updating and getting failing throwing the ” Cannot execute upgrade script on host” error message.
Actually, I have done host upgrades in many times but I did not get such issues with Cisco UCS blades and other ESXi hosts. But I got this error couple of times with these Dell hosts. I’m not sure whether there is a relation to the vendor but this is how I resolved this issue while I’m doing the ESXi upgrade.
I checked the disk space of the host and I noticed that one of the vfat scratch partition is full. I used “df -h” command to check the disk space to get only the vfat partitions use “df -h | grep vfat“. Here is the output.
I executed “du -h /<my_vfat_volume>” to get the breakdown of the utilization
I removed the “6.5.0” folder inside the packages folder. Executed “rm -rf <folder_name>” to remove the folder
Now located a “vpxa-worker-zdump.xxx” file in the /var/core/ folder removed the dump file. Executed “rm -rf vpxa-worker-zdump.xxx” command to permenetly delete the file [Step 7]. See the below detailed steps.
Again, checked the vfat partition space and now it is 0% utilized.
I started the upgrade and it was succeeded after that. Hope this post will help someone who experience the similar issue while doing the upgrade.