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From: Gabriel de Perthuis <g2p.code-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: Poor performance with bcache write-back mode
Date: Fri, 17 May 2013 20:50:08 +0000 (UTC)
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On Fri, 17 May 2013 13:13:04 -0700, Patrick Ng wrote:
> Hi Robert,
> 
> I have checked that the cache partition (/dev/sdc1) starts at 2048, it should be properly aligned.
> Similarly for the backing store partition (/dev/sdb1), it starts at 2048 at well.

The bcache superblock shifts the start of your partition by 8k though.
I don't know if the upper layers compensate for that, but just in case,
you may want to add `--data_offset 2048` to the make-bcache command line
(1M alignment).