I'm using HP power manager 4.2.7 on Win2008 x64. But I've seen similar behaviour on Win2000 and older HPPM version.
The problem is with data logging. I've set log interval to 5mins. All data is logged in \Program Files (x86)\HP\Power Manager\DeviceData.log, and I see in that file that all records are saved correctly. But when I go to web interface, I can see graphs cutting off at some particular date. Exporting log also works only up until that date. If I want to view log online, after 15-20 "next" clicks I can reach a few pages dated May, but nothing more.
To be precise, my logging started at 08 May 2009 13:17:03 GMT, and I can't see records after October 08 2009,18:37:13. I'm sure that there was nothing touch on the server at that time.
The file size now is 9.5mb, so I tried to delete all records after 2009 October 08 using text editor, and I got the file size 8.723.030b. Doesn't seem like its the 8388608 bytes limit (8mb) limit.
Question: is there a log file size limit? If not, what is going on?