On Mon, Apr 25, 2005 at 12:06:10PM -0400, Luben Tuikov wrote: > On 04/24/05 07:19, Christoph Hellwig wrote: > > > > This is contrary to any sysfs topology I know about, especially any > > existing transport class (SPI, FC, iSCSI). > > This RFC is about SAS. But our SAS transport class should be consistant with the other transport classes. > > We only ever care about what's seen from a HA, > > Imagine you could connect to the same device via two > different PCI controllers on the same host. Which is exactly the case in the examples I've mentioned. > > > e.g. if you have muliple SPI cards that are > > on a single parallel bus you'll have the same bus represented twice, > > similarly if you have two fibre channel HBAs connected to the same > > SAN you'll have the SAN topology duplicated in both sub-topologies. > > Hmm, this proposal is for SAS only, Christoph. > > If you have multiple SAS host adapters connected to the same > SAS domain, the _path_ they connect to a SAS device may be _different_. > But what is the same is the SAS domain (topology) itself *regardless of > how you connect to it.* > > In order to eliminate duplication of sysfs entries (directories > and files) to describe the same SAS device, we split up the > representation into a "flat" directory with just a bunch > of SAS devices, this is /sys/bus/sas/. And the way you _connect_ > to those SAS devices is represented in sys/class/sas_ha/. Please read the previous mail again, you're not getting it at all. If you don't understand the problems it's not worth talking about more. - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
