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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!news.wildstar.net!serv.hinet.net!news.uoregon.edu!arclight.uoregon.edu!gatech!news.mathworks.com!fu-berlin.de!zrz.TU-Berlin.DE!news.tu-chemnitz.de!irz401!orion.sax.de!uriah.heep!news From: j@uriah.heep.sax.de (J Wunsch) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Disk drive device names Date: 9 Jul 1996 21:34:42 GMT Organization: Private BSD site, Dresden Lines: 37 Message-ID: <4ruj9i$5ho@uriah.heep.sax.de> References: <4rrn16$eml@viking.mpr.ca> Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) NNTP-Posting-Host: localhost.heep.sax.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: knews 0.9.6 X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E rosenaue@mpr.ca (Dennis Rosenauer) wrote: > Could anyone enlighten me as to the difference between for example > wd0e and wd0s1e? There used to be some explanation for how slices are working, but it's well hidden on either the installation floppy, or for those with a full source distribution under /usr/src/release/sysinstall/help/. Basically, wd0s1e is partition `e' on the first slice of wd0. The first four slices match the first four table slots in the fdisk (``slice'') table, regardless of whether they contain valid data or not. So-called ``extended partitions'' are known as slices #5 and upwards (wd0s5...), but *only* if they are actually existing. wd0e is the `e' partition from the ``compatibility slice''. The latter refers to the first BSD slice (0xa5 signature) that is found in the fdisk table, and it exists for historical reasons, i.e. compat- ibility with programs that don't know about slices. Note that one of these programs is the bootstrap loader itself, therefore you can only boot off the compatibility slice, and you always see /dev/wd0a mounted as the root file system (where the `sliced' notation would be /dev/wd0s1a). wd0e could also be partition `e' for a non-sliced disk, i.e. where the fdisk table doesn't contain valid data. This covers the historical ``dangerously dedicated'' case as well as some other cases where the first sector doesn't contain an fdisk table. This is apparently not of your concern if you are sharing your disk with other systems (since *they* always need the fdisk table). -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)