Subject: Re: pkgsrc reorg proposal II (dist as vnd FS)
To: John Refling <johnr@imageworks.com>
From: Al Snell <alaric@alaric-snell.com>
List: tech-pkg
Date: 01/26/2001 20:55:03
On Fri, 26 Jan 2001, John Refling wrote:

> Is there an endian independent filesystem or one that can mount
> a different endianness filesystem than the host?

Yep. In the kernel config, you can enable endian independent FFS. It's a
bit slower and larger since the system has to do checks and branches all
the time, but it's easy to enable.

OR: you can use cd9660 filesystems, which are downright portable, and
optimised for read only access.

> pkgsrc.tar.gz =  6,364,609 bytes
> pkgsrc.tar    = 55,582,720 bytes
> pkgsrc.vnd    = 68,157,440 bytes
> pkgsrc.vnd.gz =  6,521,966 bytes

Ahah!

> So, no great loss of storage.  Would be nice to have a
> *compressed* vnd file system, even if readonly!

Yeah. A fast, compressed, read only file filesystem could be made. Like a 
tarile, all files are contiguous - and then divide it into blocks of 64k
or more and individually gzip them. Append an inode table, with each inode
containing the file offset of the block to look in, then the offset within
that block of the file or directory data. The inode table itself would be
gzipped.

Or bzipped, for that matter.

The system would have to be able to buffer up to 64k of uncompressed data
at a time (ooh, scarey), but you'd get random read access in a compressed
file.

ABS

-- 
                               Alaric B. Snell
 http://www.alaric-snell.com/  http://RFC.net/  http://www.warhead.org.uk/
   Any sufficiently advanced technology can be emulated in software