grant@cft.philips.nl (Joe Grant) (09/21/90)
I have a question about the meaning of the X in cNd0sX used for the disk device in /dev/dsk. I'm currently trying to setup a file system on a SyQuest removable cartridge which I initialized using MicroNet Utility 4.4 and partitioned with a single partition (partition 0). When I read the manual it talks of using the /dev/dsk/cNd0sX device address where N is the SCSI ID of the drive and X is the slice. What do they mean by slice? Does it correspond to a partition, i.e in this case cNd0s0, or is it something else entirely? In one part of the manual it does say that slice 3,4,5 and 6 can be used for /user or /users while slice 2 is for /usr, what do they mean by this, what are slices 0 and 1 reserved for, and what happens after slice 7? Any help would be appreciated. Joe Grant -- Joe Grant, Telex : 35000 phtc nl/nlmtfarr Philips B.V., Building HKJ-p833, Telefax : (31.40.7)37222 P.O. Box 218, 5600 MD Eindhoven, E-mail : grant@nlccl.cft.philips.nl The Netherlands. Telephone : (31.40.7)34382
rmtodd@servalan.uucp (Richard Todd) (09/22/90)
grant@cft.philips.nl (Joe Grant) writes: >When I read the manual it talks of using the /dev/dsk/cNd0sX device >address where N is the SCSI ID of the drive and X is the slice. What >do they mean by slice? Does it correspond to a partition, i.e in this >case cNd0s0, or is it something else entirely? In one part of the manual Yeah, it corresponds to a partition, but partition numbers don't necessarily correspond to slice numbers. You can either dynamically assign a named partition to a slice by the pname command or (in A/UX 2.0) set a "default" slice number for a partition in dp, so that every time you boot /dev/dsk/ cNd0sX gets automatically assigned to partition "foo". >it does say that slice 3,4,5 and 6 can be used for /user or /users >while slice 2 is for /usr, what do they mean by this, what are slices >0 and 1 reserved for, and what happens after slice 7? 0 and 1 are in the default A/UX partitioning scheme given to the root file system and the initial swap partition; if you installed with /usr as a separate filesystem, it gets slice 2. On a drive that's not your A/UX root drive (i.e. your SyQuest), that you're not going to try to boot from, it's perfectly ok to use slice numbers 0,1,2; in fact, my external HD currently has slice 0 as a big partition mounted on /u, slice 1 as a second swap partition, and 2 as /tmp. As for slice #s >= 7, I doubt there'd be a problem, except that you'd have to mknod the appropriate block special files yourself (the ones supplied are only for slices 0-6, 30, and 31). Slice 30 seems to be reserved for the MacOS partition and slice 31 corresponds to the whole disk. -- Richard Todd rmtodd@uokmax.ecn.uoknor.edu rmtodd@chinet.chi.il.us rmtodd@servalan.uucp