asked on

Memory info

Hi,

I am trying to obtain info regarding a solaris server´s memory.

I have used VMSTAT, PRSTAT, TOP, GLANCE and CACTI so far. Each of them give a different value/ percentage. I understand that some give a reading of SWAP, other Virtual and so on..

BUT, which is the one I can actually rely on ? I am implementing a monitoring system using Nagios and this value will be sent to a helpdesk team and I want to be absolutely sure of what I am sending..

Can anyone please help me out ?

thnx,

ASKER CERTIFIED SOLUTION

sheetbird

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

sarvendra

Please try following:
#prtconf |grep Memory ---to get total physical memory

#swap -l ---To get total virtual memory of system.

#ps -e0pid,vsz,args|sort +1n|tail ---to get memory utilization processwise

#use vmstat 20 ---to get system memory utilization every 20 sec

Hope this will serv your requirement.
Sarvendra

Nukfror

As sheetbird suggests, Scan Rate is the better variable to watch. If a system has adaquate memory, the scan rate should always be 0. "Paging" will ALWAYS occur on pretty much any UNIX system. If you "cat" a file, you do some number of page-ins. If you write a file, you generally do some number of page outs.

Page scanning from time to time isn't going to hurt you. Page scanning for extended periods of time will. The "free" column in vmstat will always gravitate to a point in memory known as LOTSFREE for numerous factors - the large contributor to this behavior is the FS Page Cache. The FS Page Cache caches file system related content into memory. Reading something from memory is orders of magnitue faster then reading from disk. LOTSFREE is point where the page daemon gets more aggresive at looking for pages that can be freed and when it finds these pages it pages them out by force (first to anonymous memory followed by phsyical swap) - based on a specific set of rules. This activity is what shows up as your scan rate - it only happens when free memory hits LOTSFREE and goes lower. There are two other points of memory utilization that make the page daemon gets very *more* aggressive: DESFREE and MINFREE. Course you hits these two points, you'll know it. By the time you hit DESFREE, you system may be page thrashing. MINFREE and your system may be swap thrashing.

Sarvendra,

swap -l give PHYSICAL swap space. swap -s shows virtual memory available (physical swap + anonymous memory) which changes dynamically (because of anonymous memory).

#ps -e0pid,vsz,args|sort +1n|tail ---to get memory utilization processwise - KINDA and at the same time not really for something like sgaucho is asking for.

sgaucho

ASKER

hi guys,

Thanks for the responses. The output for my VMSTAT is as fwg:

bash-2.05$ vmstat
kthr memory page disk faults cpu
r b w swap free re mf pi po fr de sr m1 m1 m1 m2 in sy cs us sy id
0 0 0 4589944 937552 210 239 1248 1 1 0 0 0 0 0 0 104 311 291 10 4 86

Accd to the above I have approx 920 Mb of Free Memory. However, I was informed earlier today that this memory is RAM + FileSystem Cache and doesnt reflect the actual free memory of the system.

Some clarification please ?

XoF

No comment has been added to this question in more than 21 days, so it is now classified as abandoned.
I will leave the following recommendation for this question in the Cleanup topic area:

Split: sheetbird & Nukfror

Any objections should be posted here in the next 4 days. After that time, the question will be closed.

-XoF-
EE Cleanup Volunteer