Automatically start hard drives and mount volumes when requested by client and unmount / shut down hdds after no usage timeout

[Niclas Arndt]

Dear all

 

I have a samba server that contains files I need to access only now and then. For this reason, I don't want the server to be running all the time. I could of course use Wake on Lan, but then I think I might have to log in on the server to shut it down afterwards. I guess I would also need a separate application to access the WoL feature over the network.

 

I am thinking along these lines: 

* A minimum samba server with mirrored system drives always running

* Software RAIDed drives that can be individually started or stopped

* HDD power controller managed via COM port communication

* When the client requests a volume that is "off line", samba tells the HDD power controller to start the required drives and mounts the volume

* The files are accessible after < 10 seconds

* After a defined no usage timeout, samba tells the HDD power controller to unmount and shut down the drives

* As a by-product, the spare drive could be powered up only when needed by mdadm

* Similarly, the HDD cage PSU sizing could be minimized due to HDD power controlled staggered spin up. (Normally staggered spin up is controlled by expensive RAID controllers - the suggested solution would only require a hot-swap compatible SATA adapter, e.g. Silicon Image.)

 

I am currently building the HDD power controller to support the above, but I lack the samba knowledge to know what already works and what would have to be developed. I also need to figure out how to communicate over the COM port in Linux. (Bash? Java?)

 

Would somebody be willing to help me along here?

 

Thanks in advance

 

Kind regards

 

Niclas Arndt

Stockholm, Sweden