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From: "Matthew Patton" <pattonme@yahoo.com>
To: linux-bcache@vger.kernel.org, Pavol Cupka <pavol.cupka@gmail.com>
Subject: Re: 2 drives btrfs raid1 with one ssd
Date: Sun, 15 Dec 2013 20:11:45 -0500	[thread overview]
Message-ID: <op.w75uxvdkf3gqgg@desktop.patton.net> (raw)
In-Reply-To: <1387155717.6876.29.camel@N900-P>

On Sun, 15 Dec 2013 20:01:57 -0500, Pavol Cupka <pavol.cupka@gmail.com>  
wrote:

> I would like to use a bcache for btrfs filesystem residing on two  
> identical disk as raid1 using btrfs' raid (without soft/hard raid).
>
> Is it possible?

if I understood you correctly, no.

> I would like to use the same ssd/ssd partition for caching both  
> drives/mirror. Is this doable?

You will have to build the btrfs 'raid' on top of two bcache devices. If  
the caching device for both devices in the same SSD (partitioned) what's  
the point? Assuming Btrfs has a similar feature set to MD's Raid1  
write-mostly, you could accelerate the one side, and run the other half of  
the mirror without acceleration. Otherwise I would just use MD's Raid1 and  
be done with it. Put btrfs/ext4/xfs on top as you like.

Does your intended workload really benefit from putting an SSD into the  
mix?

  reply	other threads:[~2013-12-16  1:12 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-16  1:01 2 drives btrfs raid1 with one ssd Pavol Cupka
2013-12-16  1:11 ` Matthew Patton [this message]
2013-12-18 19:11   ` Pavol Cupka
     [not found]     ` <1387420255.21384.YahooMailNeo@web181506.mail.ne1.yahoo.com>
2013-12-19  4:04       ` Pavol Cupka

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