Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!uxc.cso.uiuc.edu!tank!mimsy!chris
From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.unix.ultrix
Subject: Re: Getting more Inodes (Ultrix 3.0, Vax)
Message-ID: <18890@mimsy.UUCP>
Date: 4 Aug 89 02:39:29 GMT
References: <12244@grebyn.com>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 25

In article <12244@grebyn.com> karl@grebyn.com (Karl Nyberg) writes:
>I need more inodes for my news spool partition. ... [newfs -i option]
>However, decreasing the number, all the way down to 2, has absolutely no
>effect whatsoever.  The system continues to make one inode per each 2048
>bytes.

I wrote a nice article explaining this problem in response to a message
asking about newfs on Suns, and then forgot to save it.

The short answer is `fixed in 4.3BSD-tahoe; beat on DEC to update their
ufs code; in the meantime, try -c'.

The long answer (rather shortened) is that there is a hardwired limit
of 2048 inodes per cylinder group.  The only way to get around this in
the current system is to make smaller cylinder groups.  This is not
always possible, however, as the rotational layout code depends on
the number of `cylinders per cycle' (essentially, how soon does the
rotational layout pattern repeat) and you cannot lower the number of
cylinders per group below fs_cpc.  fs_cpc is aggravated by disks with
an odd number of sectors---the closer the number of sectors to a power
of two, the lower fs_cpc will be.  In particular, some drives with
67 sectors per cylinder cannot have less than 8 cylinders per group.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris