From: Neil Brown <neilb@suse.de>
To: "Alan D. Brunelle" <Alan.Brunelle@hp.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: raid10: no raid0 support?
Date: Thu, 19 Jun 2008 15:03:11 +1000 [thread overview]
Message-ID: <18521.59535.292223.722853@notabene.brown> (raw)
In-Reply-To: message from Alan D. Brunelle on Monday June 9
On Monday June 9, Alan.Brunelle@hp.com wrote:
> Is there some reason why the MD RAID10 module does /not/ support a
> "RAID0-like" configuration (-p n1)? The comments in drivers/md/raid10.c
> seem to suggest it should: "* If [near_copies and far_copies] are 1, we
> get raid0." Yet the code specifically checks for ((near_copies *
> far_copies) > 1).
You mean:
if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
(mddev->layout >> 17)) {
printk(KERN_ERR "raid10: %s: unsupported raid10 layout: 0x%8x\n",
mdname(mddev), mddev->layout);
goto out;
}
Yes, I guess that could be "nc*fc < 1". Everything else should still
work.
I cannot think of a good reason for making a raid10 with no redundancy though.
>
> Just curious, as it seems interesting that one could support RAID0,
> RAID1 /and/ RAID10 all w/ one RAID module.
Interesting: yes.
Useful: not sure.
NeilBrown
next prev parent reply other threads:[~2008-06-19 5:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-09 20:48 raid10: no raid0 support? Alan D. Brunelle
2008-06-19 5:03 ` Neil Brown [this message]
2008-07-07 12:46 ` Alan D. Brunelle
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