vail@tegra.COM (Johnathan Vail) (02/14/91)
Has anyone looked at using SCSA on non-sun platforms? Has anyone compared SCSA with CAM? I have written some unix/SCSI drivers using my own implementation of CAM. SCSA looked primising to me since I use Sun for development. When I found that SCSA only works on SPARCs it quickly lost its appeal and CAM (an ANSI spec) won out. I was pleased with the way that CAM fit together with what I was doing. Any thoughts or comments on the merits of each are welcome. jv Stattinger's Law: It works better if you plug it in. _____ | | Johnathan Vail | n1dxg@tegra.com |Tegra| (508) 663-7435 | N1DXG@448.625-(WorldNet) ----- jv@n1dxg.ampr.org {...sun!sunne ..uunet}!tegra!vail
mjacob@wonky.Eng.Sun.COM (Matt Jacob) (02/14/91)
A few points: + SCSA *is* available on non-SPARC sun machines (but not as a bundled part of the OS. Grrr! Not my choice...). + SCSA and CAM address a lot of the same issues. In all fairness CAM goes a bit further than SCSA in defining ways of allowing transport modules (host adapters drivers) to be plugged into it. We are considering doing this for SCSA also, although my take on this issue is that the population of target drivers is 100s to one host adapter driver. On the other hand, SCSA is a lot more lightweight than CAM (I imperfectly understand CAM as yet, but it seems to me that performance issues was a non-goal in the CAM effort- I am looking at the latest CAM specs in a couple weeks so I'll have a better idea then). SCSA kept itself as thin as possible in order to provide (in my opinion) a very aware balance between the tradeoffs of portability/platform-independence and speed. + CAM hasn't got much field experience yet. That is, it is in the process of final definition, but hasn't been out in the field for a couple of years (as far as I know). + SCSA's original goal was to unify a driver architecture across all Sun platforms. It can be extended to non Sun machines (nothing in the spec itself precludes this). The forum for doing this is in the CAM process, as well as the IEEE P1256 OBIOS effort, plus other areas. -matt