VMware ESX – failed to install Virtual Center Agent

The error, which this post is about, can have a variety of causes. I will focus on this, which I have encountered again only because i haven’t written about it before.
The error message usually suggests improper processing of the VC Agent RPM; however, it can also signify problems running the new vpx process. vCenter reports installation success only when it receives first heartbeat from the service. It is quite possible that the service fails to start, although

 service vmware-vpxa restart

is executed correctly. Similarly, causes suggested by


can be wrong.
This time, the problem was incorrect certificate file format. Unfortunately, VMware doesn’t recognize standard and widely used PEM format, which is provided by most Certification Authorities. Instead, it uses its own version of PEM format. It is the so-called, text PEM representation. To create such, you need to issue the following command:

 openssl x509 -text -in /etc/vmware/ssl/rui.crt -out /etc/vmware/ssl/rui.crt

A chance for diagnosing this mistake is interpreting of a little known log file


. After experiencing this situation, the vpx agent logs there a message about impossibility of certificate file interpretation.
I think that in this log file can be helpful in other problems with vpx agent, too.