From mboxrd@z Thu Jan  1 00:00:00 1970
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
In-reply-to: Your message of "Fri, 22 Apr 2011 09:05:16 EDT."
	<770447f0b2403cebfda8add66dfca662@ladd.quanstro.net>
References: <255556ff42dac9585ddf5e7f766d7175@hamnavoe.com>
	<20110421211046.C474DB835@mail.bitblocks.com>
	<9482032322d5daaadceace1f6875dad3@coraid.com>
	<20110422080352.DF703B835@mail.bitblocks.com>
	<770447f0b2403cebfda8add66dfca662@ladd.quanstro.net>
Date: Fri, 22 Apr 2011 10:47:08 -0700
From: Bakul Shah <bakul@bitblocks.com>
Message-Id: <20110422174708.26B5CB827@mail.bitblocks.com>
Subject: Re: [9fans] Q: moving directories? hard links?
Topicbox-Message-UUID: d2531c3e-ead6-11e9-9d60-3106f5b1d025

On Fri, 22 Apr 2011 09:05:16 EDT erik quanstrom <quanstro@quanstro.net>  wrote:
> > It all boils down to having to cope with individual units'
> > limits and failures.
> >
> > If a file needs to be larger than the capacity of the largest
> > disk, you stripe data across multiple disks.  To handle disk
> > failures you use mirroring or parity across multiple disks.
> > To increase performance beyond what a single controller can
> > do, you add multiple disk controllers.
>
> striping, mirroring, etc really don't need to affect the file system
> layout.  ken fs, of course, is one example.  the mirroring or striping
> is one example.  in the case of ken fs on aoe, ken fs doesn't even
> know at any level that there are raid5s down there.  same as with
> a regular hba raid controller.
>
> since inside a disk drive, there is also striping across platters and
> wierd remapping games  (and then there's flash), and i don't see
> any justification for calling this a "different fs layout".  you wouldn't
> say you changed datastructures if you use 8x1gb dimms instead of
> 4x2gb, would you?

I am not getting through....

Check out some papers on http://www.cs.cmu.edu/~garth/
See http://www.pdl.cmu.edu/PDL-FTP/NASD/asplos98.pdf for instance.