Dear All, 

We have a INFORMIX 14.10.FC11 instance and it runs on Redhat 9. 

We have allocated 7722628KB memory for INFORMIX ( e.g onstat - ) . The system memory is 16GB approximately.

Pl. see the 'onstat -g osi' and top output of this server. We have taken those outputs when there are no user activities in the server.

Here is a part of the 'Onstat -g osi' Output 

Top output
MiB Mem :  15531.5 total,   4782.6 free,   3100.1 used,  10160.9 buff/cache
MiB Swap:      0.0 total,      0.0 free,      0.0 used.  12431.4 avail Mem

Here are the outputs when the INFORMIX server is in the offline mode. 

Part of the 'onstat -g osi' Output

Even it  INFORMIX takes 7GB free memory We can see that there is a mismatch of free memory for 'onstat -g osi' and 'top' outputs. 

Would you pl. help us to explain this matter?

Thanks !

Best Regards,

Indika 

Hi Indika,

not that I'd be an expert in this area, but is it possible this system has more RAM than those approx. 16GB you mentioned, and a portion of this is configured as large/huge memory pages (for Informix' consumption) AND this set-aside memory isn't included in top or onstat -g osi numbers?

> grep -i huge /proc/meminfo

Just a thought...