[comp.sys.sun] vmstat

smb@tove.cs.umd.edu (Steve M. Burinsky) (03/19/91)

Is vmstat broken?  Two fields of significant interest to me, namely avm
and sr, are always 0.  Avm is the number of active Kbytes of virtual
memory.  Sr is the number of pages scanned per second by the clock
algorithm.  How can I get good numbers?  I've seen this behavior on both a
4/60 running SunOS 4.0.3c and a 3/280 running SunOS 4.1.1.

Steve Burinsky
smb@tove.cs.umd.edu

cd@sei.cmu.edu (Chas DiFatta) (03/22/91)

We have a 4/490 that's *very* heavily overloaded by bulk NFS traffic, X
terminal sessions, etc etc.  Does anyone know if vmstat(1) can be trusted
to give some type of reasonable representation of virtual memory
statistics.  The OS version is 4.1_PSR_A.

Chas DiFatta					chas@sei.cmu.edu

smc@styx.desktalk.com (Steven M Cohn) (04/02/91)

Regarding the two questions on vmstat(8) in v10n57, vmstat is somewhat
brain dead.  I was up in Milpitas at Sun's advanced System Administration
class, and our instructor told us that both fields 'avm' and 'at' were
meaningless.  On my system, they are always zero.  I usually get good data
for sr, however, the system must be pretty heavily loaded to get a value.
In general, you have to be paging fairly heavily to get this number above
zero for any length of time.

I have class notes available by fax for anyone really interested.

Steve Cohn
smc@desktalk.com