Messages in this thread | | | Date | Thu, 15 Jan 1998 16:11:56 -0800 | From | "Leonard N. Zubkoff" <> | Subject | Re: devfs |
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Date: Fri, 16 Jan 1998 09:53:07 +1100 From: Richard Gooch <rgooch@atnf.CSIRO.AU>
What does *BSD/Intel have as it's naming scheme for partitions and for slices?
Pre-emptive proposal: it we have to deal with partitions *and* slices, one possibility is to munge the partition ID and slice ID together. The first N "subdevices" (s) would be real partitions, the remaining subdevices would be slices within partitions. However, this I consider messy. You would have to know how many real partitions you have and which ones have how many slices. So, it would be more logical to have a naming scheme for controller,bus,target,device(lun),partition thus: /dev/sd/c0b0t0d0p1 a whole partition
Then, if any slices are found in partitions, you would also have: /dev/sd/c0b0t0d0p1s3 a single Solaris slice within a partition
and of course: /dev/sd/c0b0t0d0 a whole disc
Leonard: what do you think of this? I don't think we can ignore the fact that partitions and slices are different. Munging them together only partially hides it. Also, if we were to go back to "p" for partition, how about "u" for LUN?
To some extent, we already have this situation with "normal" PC style partitions. The "extended" partition is split into "slices" called logical partitions similarly. In Linux we number those from 5..N after the four primary partitions, but I don't believe this is universal with other PC operating systems; I seem to recall that DOS calls these Logical Partition 1, and so on. If we're going to be consistent with using a new letter for subdivisions, then we really should allow for only 4 primary partitions, some of which may be divided further. Now, do Solaris slices live within both primary and logical partitions, or only within a primary partition? How about BSD? Is it legal to have multiple extended partitions each containing logical partitions, or only a single one?
Perhaps I've missed something, but I still don't feel that we've seen a complete description of how BSD and Solaris present these subdivided partitions to the user. It doesn't bother me terribly much to have slices just using higher numbers as we do now for logical partitions, but I don't know if the structure is simple enough to allow for that. This is getting complicated fast... we really need to know the full structure we need to address if we want an all-encompassing solution. What would a multi-boot system with Linux, BSD, Solaris, and Win 95 or NT look like?
If we can get away with "d" (device) and "s" (subdevice) without building a complicated and fully general tree, I'm still in favor of that.
Leonard
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