proc: table is full system errors.

[Gino Castoldi_2]

Hi,

HP-UX 11.0 2GB memory Oracle 8.1.6.3 VPO 6.14.

We recently received these errors because a job
spawned too many processes. It looks like that the kernel has the max limit for 'nproc' set to 820.

sar output:
07:42:51 text-sz ov proc-sz ov inod-sz ov file-sz ov
07:42:52 N/A N/A 198/820 0 1020/1020 0 1598/4142 0

Do we just need to increase the kernel parameter 'nproc' to a higher value?

Is there a way to calculate what the kernel
values should be set to?

10 points to any good answer.
thank you
Gino

[Pete Randall · Accepted solution]

Gino,

If you have Glance, take a look at the system tables report. That will tell you current utilization and the high water mark for NPROC (and other) kernel parameters. I would suggest doubling the value of NPROC. All it's going to consume is a small bit of RAM to hold the extra kernel structures. Or you could double MAXUSERS, assuming that NPROC is still based on the (20+8*MAXUSERS) formula.


Pete

[Gino Castoldi_2]

Pete,

On our systems the value of 'nproc' is this:
(20+25*MAXUSERS)
I checked the values of maxusers/nproc using 'kmtune'.

10 points to any good answer.
thank you
Gino

[James R. Ferguson]

Hi Gino:

Yes, the ceiling 'nproc' needs to be increased if your application is functioning as intended. A small amount of memory will be consumed to support the increased fence as 'nfile' and 'ninode' will increase along with the change to 'nproc'. A reboot will be required to change this kernel parameter.

Regards!

...JRF...

[Pete Randall]

Gino,

Regardless, either double MAXUSERS or change replace the formula for NPROC with an explicit value that is double the current.


Pete

[Pete Randall]

Sorry, make that "change/replace".


Pete

[Gino Castoldi_2]

Hi,

Is there any way to calculate how much more memory these changes will use?
I'm just concerned that we may not have enough memory?

10 points to any good answer.
thank you
Gino

[Pete Randall]

Gino,

The amount of memory is inconsequential - measured in hundreds of bytes - probably less than 1MB.


Pete

[James R. Ferguson]

Hi Gino:

Changing 'nproc' or changing 'maxusers' and allowing that change to inflate 'nproc' isn't going to consume large amounts of memory. FOr the most part, 'nproc', 'nfile' and 'ninode' values represent "slots" in kernel tables and as such are small structural units. You can set 'nproc' to some value, or use the formula and change the pseudo-parameter, 'maxusers'.

Regards!

...JRF...

[Bernhard Mueller]

Gino,

in fact if you take Oracle's recommendations for HP-UX kernel parameters you will have an nproc value of 4096 for Oracle 9i.

Not sure what the official recommendations were for 8.1.7.x but the Oracle 8 servers I know typically have nproc set between 1024 and 4096.

Regards,
Bernhard