RE: differences in v$OSSSTAT based on OS

V$OSSTAT is dependent on two things:

1. what OS statistics the OS provides (and not the most recent version out there, but the base OS release that Oracle version was designed to be compatible with)
2. what OS statistics the Oracle OSD layer uses

As far as I know, Linux doesn't account the time spent queueing for CPU for example. This may have changed in recent Linux kernel versions... at least vmstat -s in OEL5.1 doesn't show OS cpu wait time yet:

LIN10G1$ uname -a
Linux linux01 2.6.18-53.el5 #1 SMP Sat Nov 10 18:24:52 EST 2007 i686 athlon i386 GNU/Linux
LIN10G1$ vmstat -s

      4091292  total memory
      3205232  used memory
      1660960  active memory
      1443964  inactive memory
       886060  free memory
       208220  buffer memory
      2410484  swap cache
      8388600  total swap
            0  used swap
      8388600  free swap
        57752 non-nice user cpu ticks
        19989 nice user cpu ticks
        42029 system cpu ticks
      5877998 idle cpu ticks
        64425 IO-wait cpu ticks
          998 IRQ cpu ticks
         4176 softirq cpu ticks
            0 stolen cpu ticks
      1132249 pages paged in
      2392334 pages paged out
            0 pages swapped in
            0 pages swapped out
     15605774 interrupts
     38908593 CPU context switches
   1214423725 boot time
       210950 forks

Maybe there's a way (in form of kernel patch hack to enable this), for example on Solaris these stats are enabled using microstate accounting...

--
Regards,
Tanel Poder
http://blog.tanelpoder.com
 



> -----Original Message-----

> From: oracle-l-bounce_at_freelists.org 

> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Milen Kulev

> Sent: Wednesday, June 25, 2008 21:42

> To: oracle-l_at_freelists.org

> Cc: oracle-l-bounce_at_freelists.org

> Subject: differences in v$OSSSTAT based on OS

> 

> 

> Hello Listers,

> I have noticed that v$OSSSTAT is giving me very different set 

> od statistics depending on the OS where it is issued  (HPUX 

> 11.11 und Suse Linux 9.3  in this case):

> The results :

> 1) On Linux

>   select * from V$osstat ;


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