safe nfile range

[Shawn Miller_2]

I have been advised by my oracle dbas that they are having problems opening up databases and need the nfile parameter to increase. Is there a formula or recommendation for nfile number based on physical memory in the server. This is 11.00 and k460 server with only 3GB of memory. Also, should I increase maxuser and let it increase nfile or should I over ride the formula with a specific number. A general concern is increasing this too high and causing other problems.

currently maxusers is 600
nfile is 11657

[Pete Randall · Accepted solution]

Shawn,

It's not Oracle, but I've got an Informix development server with 2GB of memory that has nfile set to 114548. I think you should have no problems with at least doubling your value.


Pete

[A. Clay Stephenson]

I would decouple nfile from the maxusers formulae and simply plug in a value. You can certainly go up to 25000 without problems although don't expect this old box to be a screamer. It is important that you get your Oracle guys to tell you if they are seeing errno 23 (ENFILE) or 24 (EMFILE). One is the system-wide limit (ENFILE --> nfile) and the other is the per-process limit (EMFILE --> maxfiles, maxfiles_lim).

You really need to use Glance or sar -v to monitor the limits during busy periods.

[Geoff Wild]

I set nfile manually on my Oracle and SAP servers.

On my largest box, 1.2 TB db, 10GB of ram, nfile is set to 189090

On a 4GB of ram system nfile is 32768 with a 170GB db.

For yours - that depends. Do your DBA's have a recommended ammount? If not, then increase it gradually...

Maxuser doesn't need to be increased unless you have a lot of user connecting with telnet, etc.

Rgds...Geoff