From: Roger Binns <rogerb@rogerbinns.com>
To: linux-btrfs@vger.kernel.org
Subject: RAID 0 across SSD and HDD
Date: Wed, 30 Jan 2013 01:27:37 -0800 [thread overview]
Message-ID: <keap27$oqb$1@ger.gmane.org> (raw)
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I've been unable to find anything definitive about what happens if I use
RAID0 to join an SSD and HDD together with respect to performance
(latency, throughput). The future is obvious (hot data tracking, using
most appropriate device for the data, data migration).
In my specific case I have a 250GB SSD and a 500GB HDD, and about 250GB of
files (constantly growing). One message I saw said that new blocks are
allocated on the device with the most free space which implies the SSD
would be virtually unused in my case, except for metadata which would only
be used half the time.
At the moment I have two independent filesystems (one per device) and
manually move data files between them using symlinks to keep pathnames the
same. This requires keeping lots of slop free space on the SSD as well as
administration whenever it runs out of space.
My hope would be overall performance between that of the two devices, and
closer to that of the SSD.
Roger
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next reply other threads:[~2013-01-30 9:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-30 9:27 Roger Binns [this message]
2013-01-30 10:02 ` RAID 0 across SSD and HDD Hugo Mills
2013-01-30 10:49 ` Roger Binns
2013-01-30 12:01 ` Sander
2013-01-30 20:06 ` Roger Binns
2013-01-30 19:10 ` Filipe Brandenburger
2013-01-30 20:18 ` Roger Binns
2013-01-31 12:39 ` Piotr Pawłow
2013-01-30 18:51 ` Chris Murphy
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