topic Re: configuring nfile parameter in Operating System - HP-UX

configuring nfile parameter

Unix Team — Wed, 21 Jul 2004 09:48:03 GMT

I recieved a file table full error, looking at Glance shows alerts on file table, (nfile).

System is rp7400, 12Gb memory, H/A cluster running multiple (ie 17) progress databases. currently nfile is set to 62144. max users is 4096.

What is reasonable setting for nfiles for the amount of memory I have?

--Craig Miller
millerlc@us.ibm.com

Re: configuring nfile parameter

Pete Randall — Wed, 21 Jul 2004 09:56:23 GMT

Craig,

Similar config - rp7410, 8GB, running one Informix DB. Our nfile is 114548. I would think, with more memory on your system, you would want to go even higher than that. SAM's help on configurable paramaters says " Be generous with
this number because the required memory is minimal, and not having
enough slots restricts system processing capacity. "

Pete

Re: configuring nfile parameter

Geoff Wild — Wed, 21 Jul 2004 10:02:37 GMT

A lot depends on what is running - for instance, I have RP7410 with 10GB of ram, running Oracle/SAP - nfile is set to: 189100

My maxusers is only 256 as I don't have a lot of "direct" logins (telnet).

Rgds...Geoff

Re: configuring nfile parameter

Richard Pereira_1 — Wed, 21 Jul 2004 10:05:40 GMT

Theres no hard set number, it depends on what kind of applications you running, number of users, things like that. But like Pete said, be generous. Say, give it another 500 and then monitor it for a while, see how high it climbs during the day.

to monitor you can use either glance or

root@MyHost /root # sar -v 5 5

HP-UX MyHost B.11.11 U 9000/800 07/21/04

11:00:02 text-sz ov proc-sz ov inod-sz ov file-sz ov
11:00:07 N/A N/A 209/5120 0 937/16384 0 1387/16394 0
11:00:12 N/A N/A 209/5120 0 938/16384 0 1388/16394 0
11:00:17 N/A N/A 209/5120 0 963/16384 0 1393/16394 0
11:00:22 N/A N/A 209/5120 0 936/16384 0 1390/16394 0
11:00:27 N/A N/A 209/5120 0 939/16384 0 1388/16394 0

so this will take 5 readings with a 5 seconds delay, check the column titled " file-sz " that represents your nfile usage / total number in the kernel.

Re: configuring nfile parameter

A. Clay Stephenson — Wed, 21 Jul 2004 10:07:06 GMT

In general, the answer is as many as you need. Systems running HP's Universe database routinely need nfile settings of 200000 or more and that is on systems with far less memory than you have. Because your nfile needs are somewhat atypical, the very first thing that I would do is decouple nfile from the formula which is tied to MAXUSERS and NPROC (amoung others) and plug a numerical value in directly for nfile. Given your memory, I would probably go with a value of 250000 and monitor the usage.

Re: configuring nfile parameter

Unix Team — Wed, 21 Jul 2004 10:09:49 GMT

Thanks for the quick responses, I appreciate the info.

--Craig