Free memory usage Sol10, 8.2.9

["Subbiah Stalin-XCGF84" <SSubbiah@xxxxxxxxxxxx>]

All,

 

I'm trying to understand the free memory usage and why it falls below 17G sometimes and what could be causing it. Any pointers would be appreciated.

 

root@prod1 # prtconf
System Configuration:  Sun Microsystems  sun4u
Memory size: 32768 Megabytes

 

[postgres@prod1 ~]$ vmstat 5 10
 kthr      memory            page            disk          faults      cpu
 r b w   swap  free  re  mf pi po fr de sr 1m 1m 1m m1   in   sy   cs us sy id
 0 0 0 51713480 21130304 58 185 325 104 104 0 0 23 3 7 1 488 604  573  1  2 97
 0 0 0 51048768 18523456 6 10 0 192 192 0 0 4  0  3  0  527  753  807  2  1 97
 0 0 0 51713480 21130304 58 185 325 104 104 0 0 1 23 3 7 488 604  573  1  2 97
 0 0 0 51067112 18538472 0 1 0 171 171 0 0  4  8  0  4  522  573  740  2  1 97
 0 0 0 51072744 18542992 0 0 0 187 187 0 0  0 22  0  7  532  657  780  2  1 97
 0 0 0 51069944 18540736 146 1729 3 174 174 0 0 0 9 0 3 526 3227  944  4  5 91
 0 0 0 51065728 18537360 32 33 0 192 192 0 0 0 20 0  3  522 1147  927  3  2 95
 0 0 0 51065728 18537336 0 0 0 190 190 0 0  0 26  0  3  517  628  789  2  1 97
 0 0 0 51065728 18537336 0 0 0 168 168 0 0  0 25  0 11  517  668  810  2  2 96
 0 0 0 51062960 18535152 0 165 2 190 190 0 0 14 29 0 4  552  732  808  2  1 97

 

prstat -am

 

 NPROC USERNAME  SWAP   RSS MEMORY      TIME  CPU
    21 postgres 8312M 8300M    25% 112:24:15 2.1%
    53 root      347M  236M   0.7% 130:52:02 0.1%
     7 daemon    708M  714M   2.2%  21:53:05 0.0%
     4 mot      5552K   15M   0.0%   0:00:00 0.0%
     1 smmsp    1384K 5480K   0.0%   0:00:59 0.0%

[postgres@prod1]$ ps -eaf | grep postgres | wc -l
24

 

max_connections = 600
shared_buffers = 8000MB
temp_buffers = 8MB
work_mem = 2MB                         
maintenance_work_mem = 256MB           
max_fsm_pages = 2048000
max_fsm_relations = 2000
effective_cache_size = 4000MB

 

Thanks,

Stalin