AIX 7.2 SAS WORK log=NULL and mount options etc.

[MargaretC]

I can do that.  But there is a lot more to MAX performance than just making sure you AIX is properly tuned.  The storage needs to be configured correctly as well.  Most of the IO performance issues come from the underlying storage not being configured ideally for SAS.  Can you share with us the type of storage you will be using?  Is this storage dedicated to SAS or will it be shared with other applications?

Margaret

[HejHarald]

Hi Kurt,

Yes, I've followed them - exactement 🙂

Just one thing, how did you calculate your maxfree? Did you devide by number of mempools or not?

I was previus told to devide by number of mempools, this is not stated in the tuning guide.

It makes a huge difference in the result, when I have 7 memory pools.

BR

Harald

[Kurt_Bremser]

We don't have mempools. So I suggest to ask SAS TS, they can get back to their AIX specialists.

[MargaretC]

Harald,

The tuning guide you are referring to was produced with AIX experts at IBM and based on 10+ years of experience with SAS Foundation on AIX.  So, yes please follow all the suggestions in the paper.

If you would like for me to forward your original questions to my AIX experts, please let me know.

Cheers,

Margaret

[MargaretC]

Harald, 

Here is what my AIX experts said regarding your original post:

"If the filesystem is JFS2, yes, we recommend that they do not use logging for SAS WORK and UTILLOC. I see there's also SPDS in here. I'd go 1 step further and create an SPDSWORK filesystem for that. We've seen time and time again where locating SAS and SPDS WORK together created issues. I also see no benefit to using SMT8 personally. Legacy SAS doesn't use the extra threads, and there's some overhead in the hypervisor to maintaining them all."

Are you looking to put SAS WORK in memory?  If so, that is not a good idea at all.

Margaret