Dhanaraj M

Tips - Vnode Page Mapping for AMD64 machines

VPM has been part of SNV code and this is going to be out with S10U6 release.
Some important tips here..

VPM - enable/disable:

The VPM is enabled by default for amd64 machines. In order to disable VPM
(use seg_map), set "kpm_desired = 0" in /etc/system.
("vpm_enable = 0" does not reflect anything - Refer: 6431013)

Performance tips:

1. The default value of maxcontig is 128. Setting a higher value of maxcontig gives
a better performance.

2. The default value of UFS_HW is 16MB. This value can also be tuned (increased) to
achieve a better performance. However, increasing ufs_HW much higher can result in
disk saturation. (The optimum value can be determined by running performance tests
and the optimum value varies between different systems and disk speeds)

Posted at 10:39AM Jul 02, 2008 by dhanarajm in Sun  |  Comments[0]