Messages in this thread |  | | Subject | Re: SCSI device numbering (was: Re: Ideas for v2.1 | Date | Mon, 1 Jul 1996 15:35:22 +0200 (MET DST) | From | "Carsten Paeth" <> |
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> > [...] > So use the major number as a controller index (that's really what the major > number is supposed to be, anyway), and the minor number as the disk index. > There must be some way to pack SCSI disk info into 20 bits (8+8+4?). > > Note that this has one more added advantage: it's easy to keep the old SCSI > major number with the dynamic minors alive. The low-level controllers won't > need to know, because this translation could be transparently handled by some > higher-level translation code: the old major numbers get translated to the > 32-bit device numbers and this can all be transparent to the user (so that > old setups continue to work despite the changes to disk numbering). > > Note that having one major number per controller has lots of other > advantages: it means that controllers don't have to know about each other, > because they have complete control over their own major (unlike now, where > all controllers have the same major, and one of the things the SCSI layer has > to do is to separate out all the disk requests to different controllers and > drivers). > > I don't see any problems with this approach, anybody else?
I like this approach. But also we should have something to make the hot swap easier. I think about a /dev/root. In startup scripts it is than easy to fsck the root filesystem, remount it read-write an that perhaps check it a different controller is present, and call some scripts to change fstab or entries in /dev before continue.
> > Linus >
calle -- calle@calle.in-berlin.de
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