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, <firstname.lastname@example.org> 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
> >> 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.