On Tue, 17 Dec 1996, The Great Mr. Kurtz [David A. Gatwood] wrote:

> On Tue, 17 Dec 1996, Colin Wood wrote:
> 
> > > /: Optimization switching from SPACE to TIME
> > > 
> > I seem to remember something about this when the installer was posted 
> > (something about how it installs faster now).  I don't think that it's 
> > anything to be worried about (but I could obviously be wrong).  Either 
> > way, a NetBSD install is not going to take up any more or less space no 
> > matter how it's done.
> 
> I'm not positive about this, but I think it's referring to how much space
> to leave.  NetBSD defaults to leaving 10% free and unusable (except by
> root, of course), for use by the kernel during idle time for the purpose
> of defragmenting the partition.  I suspect that's an optimization "time"
> and that the optimization "space" is less than 10% (maybe 5, maybe 3,
> maybe 0, dunno) of buffer room.

Actually, I think it refers to whether or not small files will be 
allocated into fragments of the normal disk allocation units.  In 
optimization TIME, the file system doesn't spend the extra time looking 
for a block with a big enuf fragment left over, instead just allocates an 
entire new block;  optimization SPACE spends the extra time to look for a 
block with space left, thus taking longer but using less space.

> 
> I could be wrong with that, but it seems like the most likely explanation.
> And BTW, installer 1.0 does that if you set mkfs to optimize for space,
> too.  I remember this from many a reinstall on the PB145.  :-)
> 
> As for the other part, true.  NetBSD takes the same amount of space no
> matter what... a partition size is a partition size is a partition size,
> and a file size is a file size is a file size... or something like
> that....  Of course, if 10% is left free for defragmenting... but still,
> it's not wise to set that any lower, performance suffers dramatically....
> That is assuming that the partition is a boot partition.  If you're just
> storing backups in .tgz format on there and update them once a week,
> fragmentation isn't a big concern.
> 
> Cheers,
> 
>  /---------------------------------------------------------------------\
> |David A. Gatwood             And Richard Cory, one calm summer night,  |
> |davagatw@mars              Went home and put a bullet through his head.|
> |dgatwood@nyx.cs.du.edu              --Edwin Arlington Robinson         |
> |http://mars.utm.edu/~davagatw -or- http://nox.cs.du.edu:8001/~dgatwood |
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> 
> 
>