topic Re: Optimizing SAS on RHEL 6 and 7 in Administration and Deployment

Optimizing SAS on RHEL 6 and 7

ShelleySessoms — Tue, 01 Sep 2015 20:32:24 GMT

Red Hat’s latest release of RHEL 7 has many SAS customers looking to move from RHEL 6 to RHEL 7. If you are one of these SAS customers, please review SAS Note 53997 for a list of SAS 9.4 requirements and which components are not supported.

In addition, Red Hat has just released a new tuning paper Optimizing SAS on RHEL 6 and 7. It is important for you to follow all the guidelines for RHEL 7 in order to obtain optimal performance of SAS 9.4 on your hardware.

Re: Optimizing SAS on RHEL 6 and 7

ChrisNZ — Wed, 16 Sep 2015 11:41:55 GMT

Very interesting read. Thank you.

A missing topic in this document imho is the utilisation (or not) of Direct IO.

More information:

http://support.sas.com/documentation/cdl/en/hostunx/61879/HTML/default/viewer.htm#a003186164.htm

Discusion and benchmarks:

http://www.amazon.com/High-Performance-SAS-Coding-Christian-Graffeuille/dp/1512397490

Is Direct IO management in SAS only available under Windows and Unix and not under linux?

Re: Optimizing SAS on RHEL 6 and 7

MargaretC — Wed, 16 Sep 2015 16:54:46 GMT

Yes, Direct IO is supported with SAS on Linux. We did not cover it in the paper because there are no additional tunings that need to be done from what we have listed in the paper.

Are you using Direct IO at your customer site?

Re: Optimizing SAS on RHEL 6 and 7

ChrisNZ — Thu, 17 Sep 2015 11:38:04 GMT

Yes we do use it. The sas defaults are not suitable for sequentially reading large tables. Bufno of say 100 and sgio (windows server) typically divide reading times by 2 to 5.

Re: Optimizing SAS on RHEL 6 and 7

ChrisNZ — Thu, 17 Sep 2015 11:41:24 GMT

I reckon you should at least mention this feature in the document since I never saw if mentioned anywhere about Linux.