ML530 G2 with Ultra320 controller and drives, disappointing performance

[Tony Turner_3]

Recently took delivery of a ML530 G2 with a SA642 controller and 10 Ultra320 72GB 15Krpm drives internal. Set up as 2 x Raid 0+1 arrays for running SQL Server, using an OEM cable to connect the external SA642 interface to the second internal disk enclosure. Performance was disappointing as compared to the NetServer we are converting from. Read Customer Advisory EX030325_CW01, which indicates that under the circumstances the SCSI channels will run at SCSI 2 speeds

Have I misunderstood the issue, that with a SA642 controller and Ultra320 drives in a ML530 G2 disk enclosure (apparently SCSI 3), the effective speed will be SCSI 2?

If I have understood the issue correctly, any suggestions for getting Ultra320 performance?

Regards,
Tony T

[Sigi J]

Hi,
just a first idea: you did not mention if there is the optional BBWC-module (Battery Backed Write Cache) on your SA642, is it? If not, poor performance is normal, because your controller will not use any cache for write operations.

[Tony Turner_3]

Yup, there is a BBWC. It is operational (battery charged). Set 75% write, 25% read to reflect the expected activity

[Tony Turner_3]

Had used comparative SQL timings for performance testing. Identified SQL 2000 hotfix 815056, which appears to resolve the problem; performance now to expectation. Appears in retrospect that the content and timing of status presentation by the SA642, while clearly valid, is sufficiently different from previous controllers to cause SQL problems

Am assured by my HP rep that the disk enclosures are indeed Ultra320 capable, even though the QuickSpec says they are SCSI 3