Veritas DMP

[roadrunner_1]

Is there a real advantage of providing 4 paths to a device using veritas DMP.
Iam using 2 paths from a XP128 to 2 HBAs on the server. But I keep hearing that providing 4 paths to a device increases performance, but my concerns are with the LUN limitations on the Frame side.

Moreover, I dont see the real performance enhancement because of using 2 HBAs

What are your thoughts on this?

Points will be awarded.

[Steven E. Protter]

Assuming your two HBA cards don't have other bottlenecks such as switch configuration or contention, it would seem reasonable that the two HBA setup will improve performance and reliability.

PVLINKS on the other hand only provides failover, no increase in throughput is usually noticed.

SEP

[Sunil Sharma_1]

Advantage and disadvantage of having 2 or 4 paths depends on your I/O requirment of application. if you have lot of LUN on configured and data pump over HBA's is very high 4 path may help you but in practical purpoes two path is sufficient. It's my personal obsrvation. But 4 path can help you in case of HBA failure. If you configured 2 HBA's and one of these HBA fail then one HBA may not be able to take full I/O load so in that case 4 HBA may help.

Sunil