From Net-SNMP Wiki

Why can't I see values in the UCDavis 'memory' or 'vmstat' tree?

These mib modules are not supported on all operating systems, and will not be included on any other system. Currently, they are only supported on Linux, HP-UX (memory only), Solaris, BSDi (vmstat on BSDi4 only), Dynix, FreeBSD, NetBSD and OpenBSD. If you want to help port it to other systems, let us know.

Note that these subtrees only report the current usage when explicitly queried. They do not automatically generate traps when the usage strays outside the configured bounds. See the earlier FAQ entry What traps are sent by the agent? for more information

   FAQ:Agent
   

1. What MIBs are supported?
2. What protocols are supported?
3. How do I configure the agent?
4. How do I remove a MIB from the agent?
5. I've installed a new MIB file. Why can't I query it?
6. How do I add a MIB to the agent?
7. What's the difference between 'exec', 'sh' and 'pass'?
8. What's the difference between AgentX, SMUX and proxied SNMP?
9. What about 'dlmod' - what's that about?
10. Which should I use?
11. Can I use AgentX when running under Windows?
12. Can I use AgentX (or an embedded SNMP agent) in a threaded application?
13. How can I run AgentX with a different socket address?
14. How can I turn off SMUX support?
15. How can I combine two copies of the 'mib2' tree from separate subagents?
16. What traps are sent by the agent?
17. Where are these traps sent to?
18. How can I send a particular trap to selected destinations?
19. When I run the agent it runs and then quits without staying around. Why?
20. After a while the agent stops responding, and starts eating CPU time. Why?
21. How can I stop other people getting at my agent?
22. How can I listen on just one particular interface?
23. How do I configure access control?
24. I don't understand the new access control stuff - what does it mean?
25. How do I configure SNMPv3 users?
26. The 'createUser' line disappears when I start the agent. Why?
27. What's the difference between /var/net-snmp and /usr/local/share/snmp?
28. My new agent is ignoring the old snmpd.conf file. Why?
29. Why am I getting "Connection refused"?
30. Why can't I see values in the UCDavis 'extensible' or 'disk' trees?
31. Why can't I see values in the UCDavis 'memory' or 'vmstat' tree?
32. What do the CPU statistics mean - is this the load average?
33. How do I get percentage CPU utilization using ssCpuRawIdle?
34. What about multi-processor systems?
35. The speed/type of my network interfaces is wrong - how can I fix it?
36. The interface statistics for my subinterfaces are all zero - why?
37. Does the agent support the RMON-MIB?
38. What does "klread: bad address" mean?
39. What does "nlist err: wombat not found" (or similar) mean?
40. How about "Can't open /dev/kmem"?
41. The agent is complaining about 'snmpd.conf'. Where is this?
42. The system uptime (sysUpTime) returned is wrong!
43. Can the agent run multi-threaded?