Date: Thu, 1 Oct 2015 17:46:15 +0000
From: Hugo Mills <hugo@carfax.org.uk>
To: Sjoerd <sjoerd@sjomar.eu>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: RAID5 doesn't mount on boot, but you can afterwards?
Message-ID: <20151001174615.GK25907@carfax.org.uk>
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On Thu, Oct 01, 2015 at 07:04:43PM +0200, Sjoerd wrote:
> On Thursday 01 October 2015 02:21:23 Duncan wrote:
> 
> > That's very likely because unlike traditional single-device filesystems
> > (including single-device btrfs), multi-device btrfs has multiple devices
> > it must know about before it can mount the device, while mount only feeds
> > it one device.
> > 
> > There are two ways to tell btrfs (the kernel side) about the other
> > devices.
> > 
> > 1) Do a btrfs device scan before trying to mount.
> > 
> > 2) Name the component devices in the mount options, using the device=
> > option (multiple times as necessary to list all devices).
> > 
> Option 2 was to simplest to check and that works. Thanks for the tip!
> Still weird that my single devide SSD BTRFS bootdisk just worked fine 
> (althought it's using the uuid offcourse)...But it would imply to me that 
> there's a btrfs device scan run before mounting it.

   Not really. A single deice FS doesn't need the scan.

> Before I created the RAID5 I just had the four disks configures as JBOD in 
> btrfs (I used partitions that time though) and mounted it just fine with the 
> LABEL only, so it might be something with RAID5.
> 
> Anyway it's working now with just a much longer fstab line ;)
> 
> Cheers,
> Sjoerd
> 

-- 
Hugo Mills             | Vote early, vote often
hugo@... carfax.org.uk |
http://carfax.org.uk/  |
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