topic Re: Selective Storage Presentation performance impact in MSA Storage

Selective Storage Presentation performance impact

CA1201225 — Thu, 21 Oct 2004 13:03:03 GMT

Hello all.

Does anyone know what kind of performance impact, if any, ssp has? (2 hosts on MSA1000 w/ 1 controller)

Thanks

Re: Selective Storage Presentation performance impact

BR820135 — Fri, 22 Oct 2004 01:33:54 GMT

To my knowledge none. It's merely a matter of which WWN have access to which LUN's. All the mappings are maintained in a matrix on the controllers allowing/disallowing access to the LUN's.

Regards
Christian

Re: Selective Storage Presentation performance impact

CA817443 — Fri, 22 Oct 2004 10:13:10 GMT

John,

I don't have any metrics to back my opinion but I would think the performance impact is virtually none. SSP simply enforces which systems can see the unit and which cannot. The only time these would get referenced is when a system tries to connect.

spike

Re: Selective Storage Presentation performance impact

CA1201225 — Fri, 22 Oct 2004 10:42:49 GMT

Thanks to both Christian and spike. I believe that clarifies it for me.

John

Re: Selective Storage Presentation performance impact

CA974469 — Fri, 22 Oct 2004 19:49:14 GMT

John,

I second what Christian and Spike said. SSP has no performance impact.

Selective Storage Presentation (SSP) â SSP is a feature of the HSxxx controller that enables the user to determine which hosts will be granted visibility to a virtual disk. This is also known as "Restricting Host Access" or "LUN Masking." The RAID Array SSP feature provides a means to control access at the storageset level. SSP allows multiple servers or hosts to share access to the same RAID array safely, with each serverâ s storagesets (LUNs) presented exclusively to the server or servers that are allowed access to that storage. Additionally, SSP allows the setting of host modes for each FC HBA connected to the array and LUN offsets. The host mode is specially tailored to the storage communication techniques of the operating system. The LUN offset feature allows higher numbered LUNs in a RAID Array to be presented in a range required by specific operating systems. The SSP feature also provides a means to track the numerous FC HBAs within servers attached to a SAN, by identifying each FC HBA using the World Wide Identification (WWID).

Regards