Speeding up reading with RAID1 and --write-mostly

From: martin f krafft <madduck@madduck.net>
To: linux-raid@vger.kernel.org
Subject: Speeding up reading with RAID1 and --write-mostly
Date: Sat, 13 Sep 2014 08:01:43 +0200	[thread overview]
Message-ID: <20140913060143.GA15849@fishbowl.rw.madduck.net> (raw)

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Hello,

my laptop still has a rotational disk, and also a MMC reader, which
I never use. Having seen some SSD laptops do things blazingly fast,
I wondered if I couldn't use the MMC to help.

Assuming there is a MMC fast enough out there, how about creating
a RAID1 across MMC and parts of the rotational disk, with the
rotational disk flagged --write-mostly? This RAID would then hold
the system, while the data would sit on the rotational disk.

The theory here is that writing is going to be expensive either way,
but most of system use is reading anyway.

Does this sound like an idea worth pursuing? I am asking because
I don't really want to experiment using this laptop, which is
currently my only machine. Have you done this? Have you any
thoughts? Or is this just a bad idea?

I would appreciate CCs on replies.

-- 
@martinkrafft | http://madduck.net/ | http://two.sentenc.es/

"without a god, life is only a matter of opinion."
                                                    -- douglas adams

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