[SunHELP] Increase SHMMAX value to gain better performance?

[Dale Ghent]

On Fri, 8 Dec 2000 JasonYLPang at pg.SLR.com wrote:

| Currently, existing SHMMAX value is 270MB. Can I increase the SHMMAX value
| to gain better performance? If yes, what is the right value to be tuned?

The limit set by shmmax is just tha, a limit. It set the maximum allowable
shared memory segment size. Unless you're already hitting the 270MB limit,
increasing it won't be an instant and overwhelming win for performance.

You can set shmmax by putting the following in /etc/system and rebooting:

set shmsys:shminfo_shmax=<value>

where <value> is the number of bytes you wan tthe max segment size to
be. On 2.6, which it 32bit, that maximum possible value is 4294967295
(4GB).

/dale