Linux RAID subsystem development
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From: NeilBrown <neilb@suse.de>
To: Wols Lists <antlists@youngman.org.uk>
Cc: linux-raid@vger.kernel.org
Subject: Re: Grub2/raid quickie ...
Date: Thu, 30 Oct 2014 12:03:14 +1100	[thread overview]
Message-ID: <20141030120314.0841b558@notabene.brown> (raw)
In-Reply-To: <5451818B.6010809@youngman.org.uk>

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On Thu, 30 Oct 2014 00:08:43 +0000 Wols Lists <antlists@youngman.org.uk>
wrote:

> After my last shenanigans, I've now got my main system booting
> successfully from a raid / partition. HOWEVER.
> 
> I'm somewhat puzzled by grub.cfg, and this is in part behind why my dev
> system won't boot raid properly, I think. Grub uses two different UUIDs!?!?
> 
> One of them, (mduuid/...) is dead easy to find, "mdadm -D" gives the md
> uuid of the array. But the other one, the "root=UUID=...", I'm damned if
> I can find that id anywhere! Does anyone know a command, that will tell
> me what that id is, so I can fix grub.cfg on my development system?

blkid /dev/whatever

> 
> (As an aside, how do I retrospectively force a name onto an array so
> that I can guarantee it will be called /dev/md100, or /dev/mdhome, or
> whatever? I daren't use the /dev/mdxxx name at the moment, because they
> change and the result is a system that fails to boot, or is unusable, or
> some other malarkey. Dead easy for me to fix, but my wife will go spare!)

 mdadm --assemble /dev/mdhome --update=name  list-of-devices

You cannot do this without stopping the array, sorry.  Boot off a usb or CD
is necessary.

NeilBrown


> 
> Cheers,
> Wol
> --
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  reply	other threads:[~2014-10-30  1:03 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-30  0:08 Grub2/raid quickie Wols Lists
2014-10-30  1:03 ` NeilBrown [this message]
2014-10-30  1:21 ` Chris Murphy

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