[152122] in North American Network Operators' Group
Re: Most energy efficient (home) setup
daemon@ATHENA.MIT.EDU (Jeroen van Aart)
Fri Apr 13 15:07:31 2012
Date: Fri, 13 Apr 2012 12:06:22 -0700
From: Jeroen van Aart <jeroen@mompl.net>
To: NANOG list <nanog@nanog.org>
In-Reply-To: <20120223152935.GA8659@ussenterprise.ufp.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Leo Bicknell wrote:
> But what's really missing is storage management. RAID5 (and similar)
> require all drives to be online all the time. I'd love an intelligent
> file system that could spin down drives when not in use, and even for
> many workloads spin up only a portion of the drives. It's easy to
> imagine a system with a small SSD and a pair of disks. Reads spin one
> disk. Writes go to that disk and the SSD until there are enough, which
> spins up the second drive and writes them out as a proper mirror. In a
> home file server drive motors, time you have 4-6 drives, eat most of the
> power. CPU's speed step down nicely, drives don't.
Late reply by me, but excellent points.
A combination of mdadm and hdparm on linux should suffice to have a raid
that will spin down the disks when not in use. I have used for years a
G4 system with a mdadm raid1 (and a separate boot disk) and hdparm
configured to spin the raid disks down after 10 minutes and it worked great.
I think in a raid10 this would only spin up the disk pair that has the
data you need, but leave the rest asleep. But I didn't try that yet.
What I'd like is to have small disk enclosuer that includes a whole (low
power) computer capable of having linux installed on some flash memory.
Say you have an enclosure with space for 4 2.5 inch disks, install
linux, set it up as a raid10, connect through USB to your computer for
back up purposes.
Greetings,
Jeroen
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