Cache metadata & recent files to SSD to maximize spindown time?

[Bitbang3r]

Is there some way to set up FreeNAS server with two or more big hard drives and a SSD, using the SSD to transparently cache newly-created files, recently-modified files, recently-read files, and all the filesystem metadata from the rotating drives, so that the rotating drives can be allowed to spin down (and remain spun down) until there's some concrete need to either read a file that isn't cached to the SSD, or to periodically dump all the new/recent writes cached to the SSD to their final destinations on the spinning drives?

My main concern is noise. The last time I tried setting up a file server using Linux, the drives literally never spun down, and they collectively made enough noise to keep me awake at night unless I physically shut it down.

This isn't a server that will have multiple people using it around the clock. Its main purpose is to allow me to have a convenient place to back up my laptop to, and allow Windows & Linux to share files without mangling each other's local NTFS metadata without subjecting myself to FAT32's 4-gig limit. The general expectation is that unless I've actively opened a non-cached file within the past 5-10 minutes, the drives should be spun down, and the CPU should be throttled down to low speed & running fanless.

Can this be done? Or is this still something that's on the horizon, but not quite *here* yet?

 

[cyberjock]

Not really. The cache will cache things it thinks are important, but it prefers recently and frequently used data. No guarantee stuff won't be in RAM or the L2ARC. But even then you can't force it to store things if it doesn't make the decision you want and the drives don't spin down.

As for spinning drives down, aggressively spinning drives down shortens their lifespan considerably.

I wouldn't say its on the horizon per se because servers are not designed to have disks spinning down constantly. It shorts their lifespan and 99.99% of server owners will prefer lifespan over the convenience of a whisper quiet server. For most people its something that can be done, and for many should work. But it depends significantly on your usage of the system.

If quietness is your ultimate goal then you should consider building a server with adequate SSDs to build the entire pool out of them. Yes, it'll be expensive. But its the only way you can guarantee you will get the quietness you want.

 

[survive]

Hi Bitbang3r,

If you don't already have the hardware it's very much worth looking into cases designed with noise reduction in mind.

Head over to

http://www.silentpcreview.com/

and take a look at some of their advice & reviews....

-Will