On Thu, Jul 27, 2006 at 02:46:07PM +0200, thomas.seglard.enata at cnp.fr wrote:
Thanks for your explanation ! I'm sorry to insist but it's a bit hard to understand. I think the true problem is the "reserved" memory. It's a maximum value and may not be used totally. For me, the real information is on the first line and given by the swapdisk. In my example, I got a total of 24G for swapping (also called paging by HP) and only 23% is used.
Moreover, to determine the total physical memory used, a little script called "hpux_memory" is launched. I got very different results between this script and "swapinfo -Mm" :
bash-3.00$ ./hpux-meminfo Total:16372 Free:212
So, on my hobbit display I got percentage of memory utilisation > 95% whereas I got 29% with the other command !! Where is the truth ?!
bash-3.00$ /usr/sbin/swapinfo -Mm Mb Mb Mb PCT TYPE AVAIL USED FREE USED memory 16372 4770 11602 29%
hpux-meminfo.c uses two HP library functions to get the memory details:
pstat_getstatic(&sbuf, sizeof(sbuf), 1, 0);This provides the amount of RAM installed, and appears to agree with your "swapinfo -Mm" output (both say 16372).
pstat_getdynamic(&dbuf, sizeof(dbuf), 1, 0);This returns a "struct" (table of values) where the "psd_free" item is described as "Physical pages that the system considers to be unused and available to processes". (I believe this is described in the /usr/include/sys/pstat.h file). Through some calculations using the pagesize value also returned by pstat_getstatic, it reaches the value you get for MB free memory.
I'm not saying one or the other value is the "right" one, I don't have enough knowledge of HP-UX to judge which one is right. If the HP-UX knowledgable people around this list can let me know how to best determine the memory pressure, I'll be happy to re-do the HP-UX code to work with that.
For the swap or paging memory, "swapinfo -dm" :
The Hobbit client uses "swapinfo -tm". According to the HP-UX manpage, you only get a subset of the swap space information when using the "-d" option, which results in a misleading total:
-t Add a totals line with a TYPE of total. This line totals only
the paging information displayed above it, not all paging areas;
this line might be misleading if a subset of -dfrM is specified
-d Print information about device paging areas only.
-f Print information about file system paging areas only.
-r Print information about reserved paging space only.
-M Print information about memory paging space only.(From http://docs.hp.com/en/B2355-90692/swapinfo.1M.html)
Regards, Henrik