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Re: Alternative to using USB-Stick as mass storage on NSLU2



On Thu, 2010-02-18 at 15:33 -0500, Rick Thomas wrote:

> On Thu, Feb 18, 2010 at 18:02,  <u7l11ey@mail.lrz-muenchen.de> wrote:
> >> John Holland wrote
> >>
> >>> You could use a 2.5" HDD. The Momentus has a typical usage  
> >>> specified @
> >>> 1.5W seek and .7W idle.
> >>
> >> Thanks for pointing out the low energy consumption of modern 2.5"  
> >> HDs.
> >> Since others mentioned that SD is even less suitable for my  
> >> purpose, I
> >> think I'll go that route.
> >>
> >> Can anybody recommend a specific model of an external 2.5" drive
that
> >> works well with a slug under Debian (Lenny armel), preferably USB- 
> >> powered
> >> so I don't need an extra power supply?
> >>
> >> I've read a lot on nslu2-linux.org about spindown issues with HDs
> >> connected to a slug. Since my slug is logging data continuously  
> >> 24/7, I
> >> guess I shouldn't let the HD spin down at all. Is that assumption  
> >> correct?

On my Thecus N2100 I use laeptop-tools to have the disk spun down almost
all time. I also log data with solarpowerlog.
(Basically I have a very long commit-time for the system partions, parts
of /var/* mounted as a tmpfs or a dedicated memory stick. /tmp is alsow
tmpfs .... I can do that because my Thecus is behind an ups.
Also I made a small webinterface which allows me to set it into "low
power mode", where I stop all services which are not needed when I am
not at home.) 
 

> >>
> >> Regards, Richard
> 

> Sounds like a fun project!  Please keep us informed on what you wind  
> up doing.
> 
> If whatever you use works OK with only USB power, that's great.  But  
> I'd make sure that any external hard-drive at least has the *option*  
> of external power, incase it turns out that the Slug can't provide  
> enough to, e.g. spin-up at boot time.
> 
> Of course, external power will probably mean more total power drain  
> (due to losses in the transformer, etc...)  There are trade-offs in  
> all things.
> 
> Another low-power option would be to use a larger USB-stick (e.g. 8GB)  
> which will allow the writes to be spread over more memory cells,  
> increasing the total life of the stick.

I once read in some magazin about a kernel filesystem project especially
for flash memory (no, not JFFS or other mtd-based type). But I forgot to
note the name. (Maybe one of you can enlight me) This way I might be
possible to do a more proper wear-leveling...

> And yet a third idea: You can rent a few gigabytes of storage "in the  
> cloud" from places like Amazon.com.  Then you could use the cloud- 
> storage as an energy efficient backup for your log files.
> 
> Whatever you do, frequent backups are always a good idea.
> 
> Enjoy!
> 
> Rick
> 


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