Tim Phillips blog

Let’s have a quick look at password policy in ESX Server:
esxcfg-auth –usepamqc=N1 N2 N3 N4 N5 match
where N1 is minimal length of password, which consists only of 1 class symbols (abcdef….)
where N2 is minimal length of password, which consists of 1 class symbols or 2 class symbols (ABCdef…)
where N3 is minimal amount of letters in password
where N4 is minimal length of password, which consists of 1, 2 and 3 class symbols (ABCdef123)
where N5 is minimal length of password, which consists of 4 class symbols (first 3 classes and tech symbols !@#$%^&*)
where MATCH - is a number, where you can`t repeat symbols. For example, parameter 3 will make password 112233 unusable.
If any option will have parameter -1 it will be turned off.
Maximum amount of attempts for logging in can be set with function esxcfg-auth –maxfailedlogins=. After exceeding this number the account will be blocked. You can see amount of failed authentications by faillog -u user, and reset it by faillog -r vpxuser.