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- Xref: sparky comp.unix.ultrix:9203 comp.unix.misc:4866
- Path: sparky!uunet!news.mtholyoke.edu!jbotz
- From: jbotz@mtholyoke.edu (Jurgen Botz)
- Newsgroups: comp.unix.ultrix,comp.unix.misc
- Subject: partition & filesystem mysteries
- Date: 7 Jan 1993 13:58:02 -0500
- Organization: Mount Holyoke College
- Lines: 24
- Sender: news@mtholyoke.edu
- Distribution: world
- Message-ID: <1ihufqINNp1p@slab.mtholyoke.edu>
- NNTP-Posting-Host: slab.mtholyoke.edu
-
- I am somewhat mystified by the process of changing disk partitions
- under Ultrix (4.x). In "The Unix System Administration Handbook"
- (Evi & Nemeth) it states that BSD systems must have partition
- boundaries aligned with cylinders (or even cylinder groups?) or
- take a serious performance penalty. Is this also true for Ultrix
- (which is derived from 4.2BSD) or does the Ultrix automatically
- align partitions on cylinder boundaries? When I make a new file-
- system on a partition I created it tells me that "n sectors in the
- last cylinder are not allocated". The manual pages say nothing
- about this, and give no advice on how to calculate partition
- sizes.
-
- I tried figuring out the secret formula from the disk geometry and
- the default partitions in /etc/disktab, but didn't get very far.
- The default partition sizes are /not/ an even multiple of the number
- of sectors/cylinder. I also can't find any reasonable function that
- woud seem to determine the difference... so, what gives? There
- obviously has to be some formula based on the disk geometry, but
- I can't find it documented anywhere and I've looked everywhere I
- know to look...
-
- --
- Jurgen Botz, jbotz@mtholyoke.edu
- Northampton, MA, USA
-