In my new VMware Infrastructure 3 environment, there were times were an ESX host crashed and failed to restart. Here's the solution provided by VMware:
1. Reboot and start (Troubleshooting) console.
2. Login as "root"
3. At the commmand prompt, type the following:
"esxcfg-boot -p" (Enter)
"esxcfg-boot -b" (Enter)
"esxcfg-boot -r" (Enter)
4. The above would clear the boot ini and log files. Type "reboot" (Enter) to reboot the ESX host.
For proactive monitoring, here's what could be done:
1. Login as "root"
2. At the command prompt, type "df -h".
3. This command would display the size and % utilized for each partitions. The /boot partition should be below 50% utilized.
4. If the /boot partition is above 50%, use the procedure above and reboot the ESX server to avoid a crash.
Cheers!
