Messages in this thread | | | Date | Thu, 15 Jan 1998 17:04:34 +1100 | From | Richard Gooch <> | Subject | Re: devfs |
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Leonard N. Zubkoff writes: > From: Bob Tracy <rct@gherkin.sa.wlk.com> > Date: Wed, 14 Jan 1998 07:29:40 -0600 (CST) > > Time to lay it to rest, but here's a way for folks to live with 'd' > and 's'. Think 'd == device, s == subdevice' and assign whatever > meaning is consistent for a particular type of device. In the > System III/V way of naming things, 'd' was never intended to represent > 'disk'. The original meaning of 's' is a bit more obscure, and 'slice' > was at least as common an interpretation as 'subdevice' as I remember > it. Regardless, 'stripe' or 'strip' wasn't one of the valid meanings. > In my mind at least, there's a natural correlation between a > subdevice and a partition, and 's' isn't as limited as 'p' if/when > you want to apply the naming scheme to a device that doesn't have > partitions. > > An example: for SCSI devices, '(d)evice == LUN'. > > One more example: ESDI disks. On the old 3B2 computers with ESDI > disks, a SCSI target ID (t1-t7, t0 was reserved for the host adapter) > corresponded to a SCSI <--> ESDI controller (Everex) that could > support up to four spindles (d0-d3). Simple math implies you could > hang up to 28 spindles off a single SCSI host adapter if you were > crazy enough to put up with the I/O bottleneck. > > The ESDI example in particular is why I would prefer 'd' to 'u', but > I can live with 'u' if that's the consensus. > > The device/subdevice explanation makes a great deal of sense, and > would allow extending the naming consistently to non-SCSI devices > where the use of logical unit and slice isn't appropriate. If it's > not yet too late, I think this is a good argument for using "d" and > "s".
I guess I could live with that. It would actually bring things more into line with Solaris 2 (except that we have a bus identifier as well). However, since you raise this again, Leonard, what about the issue of slices within a partition? It appears that Solaris two places multiple slices inside a standard MS-DOS-style partition. What would you suggest to handle that? How about: /dev/sd/c0b0t0d0p1s6 :-)
Regards,
Richard....
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