nflock parameter ...

[skyblue]

the server in question is a RP v 11.0

I have some problems with an application, the people who developed that application, told me that i I have to improve the parameter named: "
nflocks"

Actually this value is : 200 and I have 2 GB of phisical memory (i do not know if is necessary this information)

Could you tell me what is the best value for that parameter ..

Thanks ....

[skyblue]

Hi, this is the server´s kernel

NAME VALUE BOOT MIN-MAX UNITS FLAGS
acctresume 4 - -200 -
acctsuspend 2 - -200 -
allocate_fs_swapmap 0 - - -
bufpages 131072 - 0 Pages -
create_fastlinks 0 - - -
dbc_max_pct 25 - - -
dbc_min_pct 5 - - -
default_disk_ir 0 - - -
dskless_node 0 - 0-1 -
eisa_io_estimate 768 - - -
eqmemsize 23 - - -
file_pad 10 - 0 -
fs_async 0 - 0-1 -
hpux_aes_override 0 - - -
maxdsiz 16384 - 0-655360 Pages -
maxdsiz_64bit 262144 - 256-1048576 Pages -
maxfiles 512 - 30-2048 -
maxfiles_lim 1024 - 30-2048 -
maxssiz 2048 - 0-655360 Pages -
maxssiz_64bit 2048 - 256-1048576 Pages -
maxswapchunks 3150 - 1-16384 -
maxtsiz 16384 - 0-655360 Pages -
maxtsiz_64bit 262144 - 256-1048576 Pages -
maxuprc 75 - -3 -
maxvgs 10 - - -
msgmap 2555904 - -3 -
nbuf 70469 - 0 -
ncallout 2084 - -6 -
ncdnode 150 - - -
ndilbuffers 30 - -1 -
netisr_priority -1 - -128 -
netmemmax 0 - - -
nfile 4146 - -14 -
nflocks 200 - -2 -
ninode 2492 - -14 -
no_lvm_disks 0 - - -
nproc 2068 - -10 -
npty 60 - -1 -
nstrpty 60 - - -
nswapdev 10 - Ene-25 -
nswapfs 10 - Ene-25 -
public_shlibs 1 - - -
remote_nfs_swap 0 - - -
rtsched_numpri 32 - - -
sema 0 - 0-1 -
semmap 4128768 - -4 -
shmem 0 - 0-1 -
shmmni 200 - 3-1024 -
streampipes 0 - 0 -
swapmem_on 1 - - -
swchunk 2048 - 2048-16384 kBytes -
timeslice 10 - -2147483649 Ticks -
unlockable_mem 8472 - 0 Pages -

Do I have to change other parameters if i change the nflocks parameters

[A. Clay Stephenson · Accepted solution]

The best value is whatever is needed and no more; that is not meant to be flippant but that is the "best" answer. Your current value of 200 is the default and that is typically on the small side; the values you need to look at are the number of files open and the number of lock regions being used. Bear in mind that a single file might have many areas of the same file locked by different processes simultaneously. Some database applications need large nflocks settings. If you have Glance installed then this is a rather easy metric to monitor.

Glance -> Reports -> System Info -> System Tables Report or System Tables Graph will list this value.

You could very easily bump the value up to 1000 or more; on some systems this value can be very large (>20000) but that atypical. Generally 1000-3000 will suffice but the "best" answer is to monitor and set the value accordingly.

[A. Clay Stephenson]

No but nflocks should bear some relationship to nfile. If you are running almost ok at 200, set it to 1000 and declare victory. Nflocks are not huge memory resource hogs but that doesn't mean you should haul off and set it to 10000 without reason.

[skyblue]

The value of maxusers is 256, do I have to increse it too?

[skyblue]

if i change this parameter, must i change other parameters?

Regards

[A. Clay Stephenson]

Maxusers is not a "real" tunable; it is a macro that is tied to various formulae that affect various other real tunables. Most experienced admins simply remove the formulae and replace them with a value. In your case, if nflocks is tied to a formula, I would replace the formula by typing over it and inserting a constant based upon system observation -- or just plug the 1000 or so as a good first start.

[inventsekar_1]

usually the application documents should say the best value. (for example when u install OVO or oracle, the installation guide will tell you the parameter values.)

othervise, experienced admins can give the best value after little bit analysis.


"The value of maxusers is 256, do I have to increse it too?"

nflocks related paramters is none. so u can change nflocks alone.

and "The default values of nproc, ncallout, ninode, and nfile are defined in terms of maxusers in the kernel-definition file, /usr/conf/master."

links for you:
Configurable Kernel Parameters(11.00)
http://docs.hp.com/en/939/KCParms/KCparams.OverviewAll.html

maxusers:
http://docs.hp.com/en/939/KCParms/KCparam.MaxUsers.html

nflocks:
http://docs.hp.com/en/939/KCParms/KCparam.Nflocks.html