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Kernel Parameters

 
Olebile
Frequent Advisor

Kernel Parameters

Gentlemen,

I have jus upgraded from HP-UX 10.20 to 11, I have a problem with the "nfile" parameter. The formulae for this parameter is different on 10.20 and 11. I am able to set this parameter to a much higher value on 10.20 but can't seem to archieve the same on 11. Does 11 handle the nfile parameter differently? I need to set the number of open files per user to a much higher value than 7049 for 400 users.

rgds

Olebile
Perfomance Monitoring is not always easy
3 REPLIES 3
Ravi_8
Honored Contributor

Re: Kernel Parameters

Hi,

In my machines the nfile values set to more than 7049 which are running 11x.

if you are not able to set using SAM.
try this method

#cp -p /stand/vmunix /stand/vmunix.org
#kmtune -s nfile=
# cd /stand/build
#mk_kernel
#mv vmunix_test /stand/vmunix
#reboot

never give up
Armin Feller
Honored Contributor

Re: Kernel Parameters

You should not change the NFILE parameter, please increase MAXUSERS till you reach 7049.

10.20
#define NFILE (16*(NPROC+16+MAXUSERS)/10+32+2*(NPTY+NSTRPTY))

11.00
#define NFILE (16*(NPROC+16+MAXUSERS)/10+32+2*(NPTY+NSTRPTY+NSTRTEL))

Regards,
Armin
eran maor
Honored Contributor

Re: Kernel Parameters

Hi

first you can delete the formula that it is in used .

here is the details about the kernel param :
nfile
nfile defines the maximum number of files that can be open simultaneously, system-wide, at any given time.

Acceptable Values:
Minimum
14
Maximum
Memory limited
Default
((16*(Nproc+16+MaxUsers)/10)+32+2*(Npty+Nstrpty)
Specify integer value or use integer formula expression. For more information, see Specifying Parameter Values.

Description
nfile defines the maximum number files that can be open at any one time, system-wide.

It is the number of slots in the file descriptor table. Be generous with this number because the required memory is minimal, and not having enough slots restricts system processing capacity.

Related Parameters and System Factors
The value used for nfile must be sufficient to service the number of users and processes allowed by the combination of nproc, maxusers, npty , and nstrpty.

Every process uses at least three file descriptors per process (standard input, standard output, and standard error).

Every process has two pipes per process (one per side), each of which requires a pty. Stream pipes also use streams ptys which are limited by nstrpty.


also you can check this link for kernel params : http://www.docs.hp.com/hpux/onlinedocs/939/KCParms/KCparams.OverviewAll.html

if you have problem with one of the params lime maxusers , first increase it and then modify the nfile .

my system has nfile with 15000 value
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