Memory bottlenecks

If the results of vmstat point to a memory bottleneck, you must find out which processes are using large amounts of memory, and which, if any, of these are growing.

Use the svmon tool:

> svmon -P -t 5

This command outputs:

-------------------------------------------------------------------------------
     Pid Command        Inuse      Pin     Pgsp  Virtual   64-bit    Mthrd
   38454 java           76454     1404   100413   144805        N        Y
-------------------------------------------------------------------------------
     Pid Command        Inuse      Pin     Pgsp  Virtual   64-bit    Mthrd
   15552 X              14282     1407    17266    19810        N        N
-------------------------------------------------------------------------------
     Pid Command        Inuse      Pin     Pgsp  Virtual   64-bit    Mthrd
   14762 dtwm            3991     1403     5054     7628        N        N
-------------------------------------------------------------------------------
     Pid Command        Inuse      Pin     Pgsp  Virtual   64-bit    Mthrd
   15274 dtsessi         3956     1403     5056     7613        N        N
-------------------------------------------------------------------------------
     Pid Command        Inuse      Pin     Pgsp  Virtual   64-bit    Mthrd
   21166 dtpad           3822     1403     4717     7460        N        N

This output shows that the highest memory user is Java™, and that it is using 144805 pages of virtual storage (144805 * 4 KB = 565.64 MB). This is not an unreasonable amount of memory for a JVM with a large Java heap - in this case 512 MB.

If the system is memory-constrained with this level of load, the only remedies available are either to obtain more physical memory or to attempt to tune the amount of paging space that is available by using the vmtune command to alter the maxperm and minperm values.

If the Java process continues to increase its memory usage, an eventual memory constraint will be caused by a memory leak.