Install to USB Drive to save power

[shahin]

HI All,

I was wondering if anyone has succeeded in installing Fedora+Amahi onto a USB drive (Flash). Please dont confuse this with installing from a USB drive.

The reason for this is to save on power as I plan to get some of the new Seagate/WD low power drives that spin down when not in use. The Flash would then hold the OS and application files but consume less power, I am aware if the speed trade-off.

Also please I would like to know if anyone has been successful with using Wake on LAN to basically put the HDA in suspended mode and then waking on LAN Activity

Thanks in advance

/Shahin
Johannesburg, South Africa

[cpg]

Hi, I believe I have seen people do that. However, not first hand details.

You probably want to mount any flash based file system with "noatime" so that each access does not generate an update every time a file is accessed. it will be a bit faster and more importantly, will not kill your flash prematurely!

[t0bbe]

I've installed Amahi on a 8Gb CF card using a IDE to CF adapter on my Intel 945GSEJT mobo.
I had absolutely no problems installing, the BIOS sees the CF as just another HDD.
Now I'm looking into how to configure Fedora/Amahi to decrease the wear on the CF by not reading/writing too often.

On my Windows 7 desktop with an Intel X-25 SSD I've disabled defragment, indexing and other things,
but I'm very new on Linux and what to look for here.

The whole thing uses 25W with two 2TB Samsung HDDs spinning, and 18W with them spinned down.

[cpg]

Very cool t0bbe!

Add noatime to the mounts so that access time is not recorded. Looking for fedora noatime this is a quick link i found. It will make things marginally faster too!

http://www.fedoraguide.info/index.php?t ... ge#Noatime

[t0bbe]

Thanks for the hint about noatime!

Now, the only thing I still have to figure out is how to get the HDDs to spin down.
They spin down ok after I log in, but if no user has logged in, then they won't spin down.

I guess this has something to do with that the settings under "power management" and "spin down hard drives when possible" only becoming active after a user has logged in, but I would like to make it the default even when the machine has booted and no user is logged in.

[moredruid]

very thorough article here.
shorter version here.

you can also run Powertop to check which devices are drawing the most current.

good luck

[toothandnail]

Thanks for the hint about noatime!

Now, the only thing I still have to figure out is how to get the HDDs to spin down.
They spin down ok after I log in, but if no user has logged in, then they won't spin down.

I guess this has something to do with that the settings under "power management" and "spin down hard drives when possible" only becoming active after a user has logged in, but I would like to make it the default even when the machine has booted and no user is logged in.

I took a slightly different route. I have two 1 TB Samsung eco-green drives for storage, and Fedora/Amahi installed on a 20 GB laptop drive that I had lying around spare. Its a bit slow booting, but doesn't have the problems associated with flash media and doesn't use much power either.

As to getting the drives to spin down, maybe you should set up automatic login to the Amahi machine. I found this on the Wiki:

http://wiki.amahi.org/index.php/VNC

The part you need is here:

Code: Select all

Setup Automatic Login Automatic login is useful if you want to run a headless HDA and enjoy the benefits that VNC provides without having to login from the command line via SSH and manually start X. Add the following to the file /etc/gdm/custom.conf #Enable Auto login to the GNOME desktop [daemon] AutomaticLoginEnable=true AutomaticLogin=<username> TimedLoginEnable=true TimedLogin=<username> TimedLoginDelay=0 Replace <username> with the username that you want to automatically login to the GNOME desktop.

Paul.

[t0bbe]

I added "noatime" to the data drives but that alone did not help spinning down the drives.
I then did:

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hdparm -S240 /dev/sda

and now my disks spin down after 20 minutes, exactly what I wanted!