system performance

UNIX HP-UX
1

hi every body i want to check system performance i usually use glance,top,sar and swapinfo but i confused in something so i need explanation about memory issue

first i want check the memory usage i used glance i found this parameter so i need one shows me the differences between these parameters

Total VM :   810mb   Sys Mem  :   747mb   User Mem:   533mb   Phys Mem :   6.0gb
Active VM:   560mb   Buf Cache:   275mb   Free Mem:   4.5gb   FileCache:      na

actually the physical memory 6 giga and the free 4.5 i understand that but need to understand what is the "Active VM: 560mb" and "Total VM : 810mb"

and are these parameters belong to swap

i run

swapinfo -mta 
             Mb      Mb      Mb   PCT  START/      Mb
TYPE      AVAIL    USED    FREE  USED   LIMIT RESERVE  PRI  NAME
dev       12000       0   12000    0%       0       -    1  /dev/vg00/lvol2
reserve       -     504    -504
memory     6132     839    5293   14%
total     18132    1343   16789    7%       -       0    -

and with glance i found swap space and swap pesudo

             Mb      Mb      Mb   PCT  START/      Mb
TYPE      AVAIL    USED    FREE  USED   LIMIT RESERVE  PRI  NAME
dev       12000       0   12000    0%       0       -    1  /dev/vg00/lvol2
reserve       -     504    -504
memory     6132     839    5293   14%Swap Device              
       
Type        Avail       Used     Priority
--------------------------------------------------------------------------------
/dev/vg00/lvol2                device      11.7gb        0mb        1
pseudo-swap                    memory       6.0gb      839mb       -1

total     18132    1343   16789    7%

also i need to understand the "pseudo-swap" i found this statement in book but don't understand "if we have 1 giga memory and 1 giga swap we can run 1.75 g processes "

ok if we don't have the pseudo-swap how much processe in this situation 1 G ? i am asking

the proplem i face i don't know the tool that tell me the accurate percentage of free memory

1- glance tell you when press "m"
Phys Mem : 6.0gb Free Mem: 4.5gb
2- glance tell you when press "w"
pseudo-swap memory 6.0gb 839mb
so from this statement we can say memory free is 6 - 839 say (1G) so the result is free memory 5 giga i don't know what is the true "4.5" or "5"
3- when use swapinfo -mat

dev       12000       0   12000    0%       0       -    1  /dev/vg00/lvol2
reserve       -     503    -503
memory     6132     839    5293   14%
total     18132    1342   16790    7%       -       0    -

so if we choose the memory + reserve we find the memory total 6 G and the user ( 503 + 839 ) = 1342 G and the free is ( 6 - 1342 ) so the result is 4802 G
so what is the true and acurate i am confused

i hope any one help me to understand what is the prarmeters i must take care about .
many thanks .

2

"also I need to understand the "pseudo-swap" i found this statement in book but don't understand "if we have 1 giga memory and 1 giga swap we can run 1.75 g processes "
ok if we don't have the pseudo-swap how much processe in this situation 1 G ? i am asking "

When a process is created, swap is checked too see if there is enough swap space for that process. The swap space is not actually allocated at that moment.
So, if you have 1 GB of RAM and 1 GB of swap space and you want to start a 1,5 GB process on a system that does not have pseudo-swap activated, you will not be able to start that process.
If you have pseudo-swap active, meaning 1 GB of swap space and [up to] 75% of 1 GB RAM results in 1,75 GB "virtual" swap space, you will be able to start that 1.5 GB process.
In HP-UX 11 v1 and v2 pseudo-swap is controlled by this kernel parameter: swapmem_on (1 is on). In 11.3, pseudo-swap is always enabled and swapmem_on parameter is no longer present.

hope it's more clear now the pseudo-swap space concept.

3

yes it is very clear thanks alot