Subject: Re: non-512-byte-sector devices vs. UBC
To: None <>
From: Simon Burge <>
List: tech-kern
Date: 06/14/1999 09:16:55
"Erik E. Fair" wrote:

> At 14:40 -0700 6/13/99, Christoph Badura wrote:
> > (Chuck Silvers) writes:
> >
> >>on a related note, it does seem odd that the current buf interface has
> >>the offset of the i/o (b_blkno) in sectors, but the size of the i/o
> >>(b_bcount) in bytes.  it would be more consistent for both offset and size
> >>to have the same units.  or are there devices that can read partial
> >>sectors, but only at the beginning of a sector?
> >
> >Tape drives do that.
> But no one uses tape drives through the block device; everyone uses the
> character ("raw") device, which does not go through the buffer cache.

Could NetBSD ever mount a filesystem off a tape device?  ISTR that
something (Ultrix?) did for it's tape install, and that it was through
the block device...