Windows Policy server keeps due to out of disk space.
When investigated many mini dump files had been created in the C:\Windows\SysWOW64 directory all having the format name : hs_err_<pid>.mdmp and had filled up the C: drive.
The hs_err_<pid>.mdmp format indicated this a dump produced by a java vm.
The root cause was a problem in the JVM, causing the crash, but the policy server was auto-restarting, and it was only when the disk became full that the outage occurred.
Windows policy server with active JVM (ie running custom code, or SAML components).
By default the JVM HotSpot JVM 1.7 with the default settings is to produce a mdmp file for each crash.
For HotSpot Java 1.7 the setting -XX:-CreateMinidumpOnCrash in JVMOptions.txt will disable producting minidumps on a JVM crash
For JVM 1.7 there is no option to change the directory where it will place the mdmps (JRocket, and Java 1.8 have more options).