nfile value

[John Curtis]

This kernel parameter is calculated by this formula (16*(NPROC+16+MAXUSERS)/10+32+2*(NPTY+NSTRPTY+NSTRTEL)). The formula is the same on all our HP servers yet the nfile parameter is larger on all our other servers.
In SAM I can't change the calculated value without altering the formula. How can I safely increase the nfile value? What in this formula is limiting the nfile value?

[John McWilliams]

Hi - I always increase the maxusers parameter to change this value. You can ignore the formula and just enter a value but this is not really a good idea. Check all the other parameter values in the formula to see if they are causing the difference

cheers John

[Steffi Jones_1]

Hi John,

you can overwrite thr formula with the value you want nfiles to be. Sam will take those changes.

I looked into the parameters you need for increasing nfiles and from that and past experience it is enough to increase maxusers, which increases nproc and then nfiles as well.

Bye, Steffi Jones

[Andy Monks]

You may also want to look at limiting vx_ninode too. If your using jfs this is very important to look at.

[Carlos Fernandez Riera]

(NPROC+16+MAXUSERS)/10+32+2*(NPTY+NSTRPTY+NSTRTEL)).

NPROC is calculated using MAXUSER
NPTY as also NSTRPTY and NSTRTEL are often a fix value (30) that are often increased.

So differences must be in one or more of these parameters.

Last time i have modified this parameter i changed the formula because each process opened at less 15 files.

[James R. Ferguson]

John:

You are correct in that 'nfile's value is based on several other parameters. My preference is to increase 'maxusers' since increasing maxusers impacts 'nproc' and both impact 'nfile'. I lean toward staying with the formulas, rather than overridding them with discrete values, to attempt to keep the best interrelationships among the various parameters.

...JRF...