linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Neil Brown <neilb@suse.de>
To: Erich Weiler <weiler@soe.ucsc.edu>
Cc: linux-raid@vger.kernel.org
Subject: Re: mdadm on huge raid sets
Date: Wed, 23 May 2007 08:12:09 +1000	[thread overview]
Message-ID: <18003.27321.583707.520299@notabene.brown> (raw)
In-Reply-To: message from Erich Weiler on Tuesday May 22

On Tuesday May 22, weiler@soe.ucsc.edu wrote:
> Greetings all-
> 
> Quick question.  We've got one of these new Sun x4500's, it is basically 
> a machine with 48 disks in it, no hardware RAID controller, so you have 
> to use software RAID, in our case mdadm because we're running RHEL 4.4.
> 
> When we try to create the raid set (RAID6), we're getting an error: 
> "Invalid number of devices" (47 devices).  We tried lowering the number, 
> and eventually it worked when we brought the number down to 27.  But 
> looking at the source code, it looks like it supports up to 256 devices 
> for RAID6... ?  Any insight would be much appreciated!!

Use "--metadata=1" to mdadm.  The 0.90 superblock has a limit of 27
devices. version 1 has no fixed limit, but the code might not support
more than 384 very well.

> 
> Thanks a million,

That would be a megathank :-?

NeilBrown

      reply	other threads:[~2007-05-22 22:12 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-22 19:51 mdadm on huge raid sets Erich Weiler
2007-05-22 22:12 ` Neil Brown [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=18003.27321.583707.520299@notabene.brown \
    --to=neilb@suse.de \
    --cc=linux-raid@vger.kernel.org \
    --cc=weiler@soe.ucsc.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).