Subject: Re: Paramaters for large drives?
To: None <netbsd-help@netbsd.org>
From: Rick Byers <rb-netbsd@BigScaryChildren.net>
List: netbsd-help
Date: 08/12/2002 18:11:57
I think I've got it working now, but I want to make sure I'm not totally
out to lunch here.  Here's what I did:
- changed the geometry to increase the number of cylinders and decrease
  the number of heads:  35556 cyl, 64 hd, 63 sec
  The boot code is accessed by block number, so it shouldn't matter
  that this doesn't match the BIOS geometry, right?
- use 8192/1024 bs/fs on all reasonably sized (<=6GB) slices
- for my big slice (62GB):
   - use 16384/2048 bs/fs
   - use the max cpg (99) - 359 groups (instead of the default ~2000)
   - use -i 16384 so I get a sane number of inodes (4M)

Sound good?

Thanks,
	Rick

On Mon, 12 Aug 2002, Rick Byers wrote:

> Hi,
> I've got a 70GB raid set that I want to install NetBSD-1.5.3/i386 onto.
> The logical disk has 8924 cyls, 255 heads, and 63 sectors.  I want to make
> a "small" root partition (512 Meg).  I used the default of 8Kb block
> size and 1Kb fragments (since the root partition will probably have a lot
> of little files on it, I'd rather not use a huge fragment size).
>
> Newfs gives an error of "With 16065 sectors per cylinder, minimum
> cylinders per group is 64.  This requires a block size of 16386 and
> fragment size of 4096."  I don't really want to use such a large frag
> size.  But if I try that, I get a warning about the rotational map not
> fitting in the super block and filesystem performance being degraded.
>
> What sort of parameters should I use for such a large drive?  I'm not too
> concerned about wasting some space (I've got way more than enough), but I
> don't want to end up with horrible performance.
>
> Thanks,
> 	Rick
>
>