Table of Contents
8 Notes on memtype parameter in proc.mem items
Overview
The memtype parameter is supported on Linux, AIX, FreeBSD, and Solaris platforms.
Three common values of 'memtype' are supported on all of these platforms: pmem, rss and vsize. Additionally, platform-specific 'memtype' values are supported on some platforms.
AIX
See values supported for 'memtype' parameter on AIX in the table.
| Supported value | Description | Source in procentry64 structure | Tries to be compatible with |
|---|---|---|---|
| vsize 1 | Virtual memory size | pi_size | |
| pmem | Percentage of real memory | pi_prm | ps -o pmem |
| rss | Resident set size | pi_trss + pi_drss | ps -o rssize |
| size | Size of process (code + data) | pi_dvm | "ps gvw" SIZE column |
| dsize | Data size | pi_dsize | |
| tsize | Text (code) size | pi_tsize | "ps gvw" TSIZ column |
| sdsize | Data size from shared library | pi_sdsize | |
| drss | Data resident set size | pi_drss | |
| trss | Text resident set size | pi_trss | |
Notes for AIX:
- When choosing parameters for proc.mem[] item key on AIX, try to specify narrow process selection criteria. Otherwise there is a risk of getting unwanted processes counted into proc.mem[] result.
Example:
$ zabbix_agentd -t proc.mem[,,,NonExistingProcess,rss]
proc.mem[,,,NonExistingProcess,rss] [u|2879488]This example shows how specifying only command line (regular expression to match) parameter results in Zabbix agent self-accounting - probably not what you want.
Do not use "ps -ef" to browse processes - it shows only non-kernel processes. Use "ps -Af" to see all processes which will be seen by Zabbix agent.
Let's go through example of 'topasrec' how Zabbix agent proc.mem[] selects processes.
$ ps -Af | grep topasrec
root 10747984 1 0 Mar 16 - 0:00 /usr/bin/topasrec -L -s 300 -R 1 -r 6 -o /var/perf daily/ -ypersistent=1 -O type=bin -ystart_time=04:08:54,Mar16,2023proc.mem[] has arguments:
proc.mem[<name>,<user>,<mode>,<cmdline>,<memtype>]The 1st criterion is a process name (argument <name>). In our example Zabbix agent will see it as 'topasrec'. In order to match, you need to either specify 'topasrec' or to leave it empty. The 2nd criterion is a user name (argument <user>). To match, you need to either specify 'root' or to leave it empty. The 3rd criterion used in process selection is an argument <cmdline>. Zabbix agent will see its value as '/usr/bin/topasrec -L -s 300 -R 1 -r 6 -o /var/perf/daily/ -ypersistent=1 -O type=bin -ystart_time=04:08:54,Mar16,2023'. To match, you need to either specify a regular expression which matches this string or to leave it empty.
Arguments <mode> and <memtype> are applied after using the three criteria mentioned above.
FreeBSD
See values supported for 'memtype' parameter on FreeBSD in the table.
| Supported value | Description | Source in kinfo_proc structure | Tries to be compatible with |
|---|---|---|---|
| vsize | Virtual memory size | kp_eproc.e_vm.vm_map.size or ki_size | ps -o vsz |
| pmem | Percentage of real memory | calculated from rss | ps -o pmem |
| rss | Resident set size | kp_eproc.e_vm.vm_rssize or ki_rssize | ps -o rss |
| size 1 | Size of process (code + data + stack) | tsize + dsize + ssize | |
| tsize | Text (code) size | kp_eproc.e_vm.vm_tsize or ki_tsize | ps -o tsiz |
| dsize | Data size | kp_eproc.e_vm.vm_dsize or ki_dsize | ps -o dsiz |
| ssize | Stack size | kp_eproc.e_vm.vm_ssize or ki_ssize | ps -o ssiz |
Linux
See values supported for 'memtype' parameter on Linux in the table.
| Supported value | Description | Source in /proc/<pid>/status file |
|---|---|---|
| vsize 1 | Virtual memory size | VmSize |
| pmem | Percentage of real memory | (VmRSS/total_memory) * 100 |
| rss | Resident set size | VmRSS |
| data | Size of data segment | VmData |
| exe | Size of code segment | VmExe |
| hwm | Peak resident set size | VmHWM |
| lck | Size of locked memory | VmLck |
| lib | Size of shared libraries | VmLib |
| peak | Peak virtual memory size | VmPeak |
| pin | Size of pinned pages | VmPin |
| pte | Size of page table entries | VmPTE |
| size | Size of process code + data + stack segments | VmExe + VmData + VmStk |
| stk | Size of stack segment | VmStk |
| swap | Size of swap space used | VmSwap |
Notes for Linux:
- Not all 'memtype' values are supported by older Linux kernels. For example, Linux 2.4 kernels do not support
hwm,pin,peak,pteandswapvalues. - We have noticed that self-monitoring of the Zabbix agent active check process with
proc.mem[...,...,...,...,data]shows a value that is 4 kB larger than reported byVmDataline in the agent's /proc/<pid>/status file. At the time of self-measurement the agent's data segment increases by 4 kB and then returns to the previous size.
Solaris
See values supported for 'memtype' parameter on Solaris in the table.
| Supported value | Description | Source in psinfo structure | Tries to be compatible with |
|---|---|---|---|
| vsize 1 | Size of process image | pr_size | ps -o vsz |
| pmem | Percentage of real memory | pr_pctmem | ps -o pmem |
| rss | Resident set size It may be underestimated - see rss description in "man ps". |
pr_rssize | ps -o rss |
Footnotes
1 Default value.