power off secondary spinning drive and work from primary SSD?

[David_Sloboda]

I am looking at getting one of the system76 laptops.
I like the idea of getting one with two hard drives: a primary SSD for the OS and /home, and a second larger spinning drive for data storage.

Is it possible with a dual drive configuration to shut off the spinning drive and work only from the SSD once in a while?
I expect that this would conserve battery life.
What command(s) would halt this secondary drive?

I have searched this forum (and a few others), but I have not yet found any details on how to do this.

Thank you for your time and response.
David Sloboda

[David_Sloboda]

I've continued searching. I found a post from January 2012
http://ubuntuforums.org/showthread.php?t=1913501
which implies that hdparm and some guesswork are required.
This other post
http://askubuntu.com/questions/19410...-of-second-hdd
has some examples.

If anyone else has any suggestions or experience here, I would be glad to hear of it.
Thank you,
David Sloboda

[tgalati4]

Search on setting up Firefox to use a RAMdisk. You can generalize that technique to work out of RAM and allow your hard disk to spin down. An alternative is to create a home directory on your SSD and write a script to back it up to your spinner once a day.

[David_Sloboda]

Thanks.
That led me to this post titled "Setting up a ramdisk"
http://ubuntuforums.org/showthread.php?t=182764
which led me to commands I understand,
and to the reference to /dev/shm

David Sloboda

[tgalati4]

Yes, that's it. There is a script that backs up the firefox profile (cache and stuff) every 10 minutes to a mirror on a hard disk. You could modify it to mirror your home directory every hour or so to your spinner.

http://www.verot.net/firefox_tmpfs.htm

[Newbunto]

I like the idea of getting one with two hard drives: a primary SSD for the OS and /home, and a second larger spinning drive for data storage.

That's basically what I have - except that the spinning drive doesn't have anything on it at all right now i.e. is completely unused.

Is it possible with a dual drive configuration to shut off the spinning drive and work only from the SSD once in a while?

I expect so but I would go further and have that as your normal configuration unless you know that you are actively using the HDD.

What command(s) would halt this secondary drive?

WARNING: It is very important that you type an uppercase S for the option in the following.

hdparm -S60 /dev/sdb

(or whatever is the correct device name for the HDD). Check the correct device name first!

That will put the drive into standby mode if not used for 5 minutes.

You can use

hdparm -C /dev/sdb

to see when the drive goes into standby.

If you want to make the change permanent then edit /etc/hdparm.conf for something like

/dev/sdb {
         spindown_time = 60
 }

In my experience on another computer (Edit: i.e. not running Ubuntu), it is very difficult to keep the drive in standby mode if the drive is being used for much. For example, some annoying software may poll a directory on the drive and thereby keep the drive awake.