AIX-VMM Tuning Parameters

AIX - Virtual Memory Tuning

In AIX, about 80% of the memory is used to buffer file I/O and only 20% is used for oracle processes and programs. This results in the double buffering of file I/O as Oracle SGA is already buffering the file I/O. It causes more Page in and Page out. To avoid this situation you must tune the Virtual Memory Parameters

To see the virtual memory Parameters use the following command.

# vmo -a

The important parameters are

strict_maxperm

strict_maxclient

lru_file_repage

maxperm%

minperm%

minperm%

minperm%

v_pinshm

maxpin%

Check whether the parameters are set to the following values, if not set it to the following values

strict_maxperm=0 (default)

strict_maxclient=1 (default)

lru_file_repage=0

maxperm%=20-30

minperm%=5 (RAM <32>32 GB but <64>64 GB)

v_pinshm=1

maxpin%=80

Thanks