page area on disk is 0 in st02 - MEMORY_NO_MORE_PAGING

Hello , we have recently updated to ERP6 EHP7 (kernel 745/301)

The customer is performing some tests and received MEMORY_NO_MORE_PAGING dump.

The dump itself says to adap rdisp/PG_MAXFS. In the end we set these 2 param.

rdisp/PG_MAXFS 65536 (twice the size as before)
rdisp/PG_SHM 32768

The weird thing is that in ST02 I see the usage of InMem but Ondisk is 0.

the file specified in dir_data exists on the OS but with size of about 256 MB, but it should be 512MB ((65536*8)/1024).

The customer performed the test again, received dump again, but still according to ST02 the page on disk has not been used.

Any idea what could be the reason? what did I miss? (or is this normal with kernel 745?, I did not find any note stating that)
thanks

Zoli