anne@nntp-server.caltech.edu (Anneliese Lilje) (04/20/91)
I am interested... When my NeXT Cube boots, it looks for all it's SCSI devices, locates them and then reports back information about the device. For example... We have an Andataco 1.2 GByte SCSI drive (Wren VII). When it boots it displays something like: Name of Disk and Model Number, as sd0 at sc0 target 1 lun 0 There is NO disktab entry for this drive on my system (yet). So what magical thing does the NeXT do to grab this information? Also, when I use build disk on the drive, it seems to understand the information above and then makes some magic assumptions about disk geometry when it formats the disk. Could someone explain to me HOW it makes these assumptions about disk geometry. Please send e-mail if possible: anne@trixie.caltech.edu
drin@nro.cs.athabascau.ca (Adrian Smith) (04/29/91)
pvo@sapphire.OCE.ORST.EDU (Paul O'Neill) writes: > In article <1991Apr19.174923.4113@nntp-server.caltech.edu> anne@nntp-server.c > > > >We have an Andataco 1.2 GByte SCSI drive (Wren VII). When it > >boots it displays something like: > > > >Name of Disk and Model Number, as sd0 at sc0 target 1 lun 0 > > > >There is NO disktab entry for this drive on my system (yet). > >So what magical thing does the NeXT do to grab this information? > > Who knows? But it's pretty cute and it's the reason I've abandoned my > project to collect and make available disktab entries for 3rd party drives. > Isn't the machine just performing a low-level SCSI MODE SENSE command? I'm by no means a SCSI or NeXTpert, but in our travails of the past two months getting our external Micropolis up on a slab, we learned a few things about SCSI. According to what I understand, the machine toggles all devices on the bus (which must support rev 17b of the SCSI command set) with a MODE SENSE command. The devices then respond with their configuration, which includes their manufacturer name, their size in bytes, and a bunch of other goodies, which the NeXT mostly ignores. The slab then returns this information, along with the appropriate device numbers, sd numbers, and lun numbers. (At least, I *think* that's how it works) -drin -------------------------------------------------------------------------- Disclaimer: How can I speak for anyone? I don't *work* for anyone!! -------------------------------------------------------------------------- Adrian Smith ersys!drin@nro.cs.athabascau.ca Edmonton Remote Systems: Serving Northern Alberta since 1982
pvo@sapphire.OCE.ORST.EDU (Paul O'Neill) (05/01/91)
In article <1991Apr19.174923.4113@nntp-server.caltech.edu> anne@nntp-server.caltech.edu (Anneliese Lilje) writes: > >We have an Andataco 1.2 GByte SCSI drive (Wren VII). When it >boots it displays something like: > >Name of Disk and Model Number, as sd0 at sc0 target 1 lun 0 > >There is NO disktab entry for this drive on my system (yet). >So what magical thing does the NeXT do to grab this information? Who knows? But it's pretty cute and it's the reason I've abandoned my project to collect and make available disktab entries for 3rd party drives. Basically, you can slave for hours optimizing a disktab entry and this automatic stuff that 2.0 does comes up within a couple of Megs of your optimized stuff. Not worth it. Paul O'Neill--Coastal Imaging Lab pvo@oce.orst.edu DoD 000006 OREGON STATE UNIVERSITY OCEANOGRAPHY ADMIN BLDG 104 CORVALLIS OR 97331-5503 503-737-3251