I currently have 2 unraid towers with 12 drives in each (1 parity and 11 data). I am working on a new tower now and I have a question....

Both towers are set to never spin down any hard drive.

 

With the rising cost of hydro, I am looking to reduce as much as I can. Is it better to have the drives spin down and if so how long before they should spin down. What is the disadvantage of having them spun down, if any?

 

I am just looking to learn a little more about spin up and spin down and how it will affect the usage of the towers.

Maybe it will not save anything at all. I don't know but I am trying to save where I can because I have 10 computers running in the house.

 

THX

We need to know more about your particular usage of the two servers in order to give you better advice.  Do they store archives or backups that are rarely accessed?  Do they store media that is accessed daily?  How often do you write to them?  Do you use a cache drive?

 

Here's some generic advice:

 

1) Leave the spin down timer at the default setting (1 hour).  Spinning up and down disks too often can wear them out quickly.  Spinning them down infrequently or never can waste power.  A 1 hour spin down timer is just right for most people.

 

2) If you have the option, you might consider combining both servers into one big one.  You would have to lose a disk or two (hopefully you could upgrade smaller disks and not lose any storage capacity), but you would save power in the long run.  You would have to figure out how the cost of the new server versus the power savings would balance out.  It is entirely possible that it isn't worthwhile.

 

The only real downside of allowing your disks to spin down is that there will be a bit of a lag when you access them.  In most cases this just means you have to wait a few seconds before you can access that disk's data, not a big deal.  However, certain programs that access the disks behind the scenes may freak out and throw up errors if the data isn't immediately available.  Most don't care, but it can happen.

 

The cache_dirs script can help keep disks spun down more of the time.  The script keeps as much of your server's directory structure in the RAM as possible (so the more RAM you have, the better).  This means that if you are, for example, browsing your media from an HTPC, all your disks will stay spun down (and there will be no spin up lag) while you browse.  Once you actually select a media file to play, then you will experience the short spin up lag while that disk (and only that disk) spins up to serve the data.

Thx for the reply.

 

Most of the disks in the arrays hold movies, which can be accessed at any time depending on what movie the kids want to watch. I think a 1 hour spindown would work for those.

I also have a backup disk in one array that is used on a daily basis for backups all over my network.

I have a picture and music disk as well that once again can be used anytime.

I have a couple other disks that just hold data. The data disk is used for downloading torrents quite a bit. I store them on the tower so they are safe.

 

 

 

OK, here's what I would do:

 

all data disks (movies, backup, pictures, music, etc.): 1 hour spin down

torrent disk: not sure yet, see below

 

Tell me more about how you are using torrents.  Does the client run on the server, or on another computer?  Does it run 24/7?  Do you consider your downloaded torrent data to be 'critical'?

I use uTorrent on my Windows machine and I have it set to save the downloadeds to the unraid tower.

Plus the same disk is used for data as well.

I consider all data on this disk to be critical.

OK, well, here's what I do:

 

I run uTorrent on a Windows computer and have it download everything to a local disk on that machine (not the boot disk).  Windows never spins down disks anyway, so the disk is always spinning.  Once a download is complete, I manually move the data to the unRAID server, redirect the torrent, and let the torrent seed from there.  Only the disks with active seeds are spun up at any given time.  The biggest downsides to this system are that the Windows machine and the unRAID server have to be on 24/7, and that there's a bit of work involved in manually moving torrents from the Windows machine to the unRAID server.

 

I'm also experimenting with running Transmission through prostuff1's great unMenu package directly on the server.  I use a cache drive for this purpose because I don't want the parity drive spinning whenever a torrent is downloading.  I'm having mixed success - the software seems to run great, but a certain tracker that I use often doesn't like Transmission (even though it is on their whitelist...not sure what is going on).  Transmission is also missing a great deal of features that uTorrent has....

 

I personally consider anything I obtain via torrents to be non-critical, since I can always just download it again.  For this reason it doesn't bother me to have newly downloaded files 'at risk' on a Windows data disk or on an unRAID cache disk.  Once the downloads are complete and I verify that the files aren't corrupted, then I move them into my parity-protected array.

 

I recommend one of these options as downloading directly to the unRAID array will cause your parity disk to be spinning nearly all the time.  If the protection from drive failure is worth it to you, then that's the sacrifice you have to make.  If you do choose to download directly to the array, then I would set your download disks to a somewhat longer spin down timer, such as 4 hours.

Thx for the info.

 

If you set a disk to spin down after 1 hour, will it spin down even if it is in use?

I hope that unraid is smart enough to know the disk is being accessed and would not spin it down.

No, a drive will never spin down when it is in use (reading or writing).  If the drive is in use when the spin down timer runs, the timer will be delayed for another time period (1 hour, 4 hours, or whatever you have it set to).

Excellent. Thx