linuxgeek: Re: [nslu2-linux] Re: Low power / quiet drive

Whatever you do, dont buy the Seagate FreeAgent series if you need them to work with the slug. I had a FreeAgent Go and it refused to play nice with Linux (NSLU2 or otherwise). There were several fixes suggested online using hdparm and changing /dev parameters - tried all of them and none worked. Not sure if the problem exists on other Seagate portable drives but I pretty much found no way out of that one.

There was a related article on Slashdot as well: http://hardware.slashdot.org/article.pl?sid=07/12/09/0651200

Too bad I found out about all this only after I had bought it :)

-H

--- On Tue, 4/1/11, Doug <dsc3507@yahoo.com> wrote:

From: Doug <dsc3507@yahoo.com>
Subject: Re: [nslu2-linux] Re: Low power / quiet drive
To: nslu2-linux@yahoogroups.com
Date: Tuesday, 4 January, 2011, 5:12 AM

Well the microdrives are small and low power but I am not sure they are more reliable. It seems there is a bunch of opinions on that.

The WD green drives seem to be OK if you can solve the head parking issue. Supposedly WD has a utility to disable or change the head parking time but it does not always work. Another work around is to do something that writes to the drive every 5 seconds. Of course you would have to make sure you flush so it actually writes. The head park default time is said to be 8 seconds, so as long as you write more often then that it will not park. Of course this somewhat defeats the "green" power of the drive - when it parks it goes into a lower power state but for Linux this park time is unrealistic.

I have always cron'ed an every minute sync on all my Linux boxes. That might be overkill but I have never had a problem. In that case if I could set the head timeout to more than a minute it would prevent the heads from parking.

This parking presents two problems. There is a limited number of parking cycles (300K) that are spec'ed and once parked there is a considerable wait to unpark and come back online.

The Seagate Momentous drives look interesting although probably not real low power they combine flash and mechanical drives on one package along with algorithms that move most often accessed stuff to flash while keeping a copy in the real drive in case of flash failure. 500GB is $120 right now. Not sure how this would play with Linux though as it has a completely different read/write pattern then a Windows machine would.

Doug

Doug Crompton
WA3DSP
www.crompton.com

From: dystopianrebel <dystopianrebel@yahoo.com>
To: nslu2-linux@yahoogroups.com
Sent: Mon, January 3, 2011 2:06:58 PM
Subject: [nslu2-linux] Re: Low power / quiet drive

I had the same concern as you do about wear-levelling on Flash memory used as an OS partition.

I have had Slug OS running on two Slugs for years (literally - five years and counting, including upgrades) on Hitachi microdrives. These products use the CompactFlash format and require a CompactFlash II type reader.

I bought the microdrives on EBay. You can search the history of this group for other discussions about microdrives.

--- In nslu2-linux@yahoogroups.com, Doug <dsc3507@...> wrote:
>
> I wonder what the groups experience has been with low power drives under Linux
> on the nslu2? I see there are a lot of complaints about the WD Cavier Green
> drives but others seem to have no problems. I want a drive that runs cool, draws
> less power, and does not require a cooling fan. 64G would be fine but I know
> that 500G is probably a minimum now days.
>
>
> I am also interested in experiences with flash drives. I would go that route but
> the uncertainty of write cycle life leaves me a little concerned. I can remember
> way back when 10K writes was the norm life, then 100K, 1M, 10M but just what
> is the write life of these 8-64G USB sticks now and are some better than
> others? I know you can do things to extend the life but what have real
> experiences been? Has anyone "burned" one of these useless on an nslu2?
>
> Doug Crompton
> WA3DSP
> www.crompton.com
>