From: <thomas.seglard.enata at cnp.fr> To: <hobbit at hswn.dk> Sent: Tuesday, July 25, 2006 2:34 PM Subject: [hobbit] Important ! HP-UX and the memory utilisation
Hello,
I got some troubles with HPUX and memory values. With Hobbit, in my memory test, I got this :
Memory Used Total Percentage Physical 16156M 16372M 98% Swap 22117M 40372M 54%
Everything seems normal but for me, these numbers are high 'cause this server does nothing during the day. So, I connected to the server and ran this command to see the available memory :
psd216:~# swapinfo -atm Mb Mb Mb PCT START/ Mb TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME dev 24000 5474 18526 23% 0 - 1 /dev/vg00/lvol2 reserve - 11550 -11550 memory 16372 4754 11618 29% total 40372 21778 18594 54% - 0 -
This output clearly shows an error in the Hobbit display. If you look, my total swap memory is equal to 24000M not 40372M as shown in Hobbit and only 23% is used !! Apparently, the values for the swap memory test are taken from the last line and that's not correct ! Then I tried to execute the binary called "hpux-meminfo" in the client "bin" directory and I get this :
The 24000M is not swapmemory it is swapdisk, ie diskdevice configured to be used for swap.
The 16372 is swapmemory or pseudo-swap as HP name it. It is a part of memory that could be used used for swapping (or as I prefer paging). If you have a lot of memory it is more efficient to use memory for paging. When a process is started in HP-UX swapdisk is reserved for the process (reserve above). If that swap isn't used, it's is waste of diskresources.
It is a try to explain.
Regards Lars Ebeling