Subject: Re: Large disk support in NetBSD, is it hard to do and is anyone working on it?
To: Thor Lancelot Simon <tls@rek.tjls.com>
From: David Laight <david@l8s.co.uk>
List: current-users
Date: 04/24/2006 21:15:35
On Mon, Apr 24, 2006 at 12:03:28AM -0400, Thor Lancelot Simon wrote:
> 
> Can you use the raw partition of the disk?  The disklabel should then be
> ignored, so should not be an issue.

Der Mouse tried that (can't remember exactly how) but then found
massive corruption problems with both FFSv1 and FFSv2.

I don't think anyone with the time + knowledge + hardware [1] has tried
to locate the fault.

	David

[1] I suspect it is possible to isolate the bug using qemu to get a large
filesystem (with few inodes) into a sparse file, then use up all the inodes
so that a high-numbered inode can be used - for which I believe the code
will allocate data blocks from the corresponding cylinder group.
Unfortunately there is no way to dump the non-sparse parts of a sparse file.

Alternatively something that transferred block read/write requests to 
userspace could be used - but I don't think that exists.

-- 
David Laight: david@l8s.co.uk