From: "Josef 'Jeff' Sipek" <jeffpc@josefsipek.net>
To: Justin Piszcz <jpiszcz@lucidpixels.com>
Cc: linux-raid@vger.kernel.org, xfs@oss.sgi.com
Subject: Re: How do I tell if my partition is aligned for a 64k/RAID-6?
Date: Sat, 27 Dec 2008 08:38:24 -0500 [thread overview]
Message-ID: <20081227133824.GH6284@josefsipek.net> (raw)
In-Reply-To: <alpine.DEB.1.10.0812251846270.32331@p34.internal.lan>
On Thu, Dec 25, 2008 at 06:46:37PM -0500, Justin Piszcz wrote:
> On Fri, 26 Dec 2008, Michal Soltys wrote:
> >> I am not worried about the filesystem as the defaults usually get it right
> >> but with parted, this is the first time I had to use it for home use and
> >> with RAID-6 I am noticing slower performance with 15 disks (1 is a spare)
> >> in RAID-6 (albeit slower 7200 ones, RE3s) than I was getting with 10
> >> raptor150s in RAID-6 (but I had used fdisk there).
> >>
> >> Justin.
> >>
> >
> > For best effect - partition should start at 1920th sector (stripe width
> > boundary), and su/sw should be appropriately set - su=64k,sw=13 in your
> > case. Parted shows the values normally - from the beginning of the volume, 0
> > based.
> >
> >
> > ps.
> >
> > I dropped some of CCs.
>
> Thanks.
It looks like you made why big partition. Why bother with partitioning at
all? If you just use the whole device, you _will_ be aligned properly if you
tell mkfs.xfs about the stripe unit/width.
Josef 'Jeff' Sipek.
--
All science is either physics or stamp collecting.
- Ernest Rutherford
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next prev parent reply other threads:[~2008-12-27 13:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-25 13:31 How do I tell if my partition is aligned for a 64k/RAID-6? Justin Piszcz
2008-12-25 22:53 ` Justin Piszcz
2008-12-25 23:02 ` Michal Soltys
2008-12-25 23:46 ` Justin Piszcz
2008-12-27 13:38 ` Josef 'Jeff' Sipek [this message]
2008-12-27 13:53 ` Justin Piszcz
2008-12-27 13:58 ` Josef 'Jeff' Sipek
2008-12-27 14:05 ` Justin Piszcz
2008-12-27 14:20 ` John Robinson
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