[SOLVED] What temp is "too cold" for unRAID operation?

[Oddwunn]

We all know the safe and optimum high end operating temperatures for hard drives, but when is it too cold? I live on the US east coast and right now outside temperatures are in the single digits, sometimes dipping below 0 degrees Fahrenheit. My server is in an unheated store room, and though I am sure that that room is not as cold as outside, it is still pretty darned cold in there.

 

My array was started, but all disks were spun down due to inactivity. Just to read the disk temps, I gave the command "spin up all disks" and the array locked up. I had to shut down very uncleanly (by switching off the power supply) and restarting. When the array came back up, I had a red ball in front of disk5, so I rebooted via the web interface. Now all of the disks are coming up again and all looks well, but I just have a suspicion that the problem is that the disks are too cold and are not spinning up quickly enough in the extreme cold.

 

On the web interface, I have seen temps as low as 9 degrees C. With all 20 disks up and running right now, the average temperature is around 12 degrees C.

 

Is this safe for my array, or is there something I can do to keep things running better during this cold snap?

[BRiT]

Check the full specifications of your hard drives. The manufacturer should always include high and low end ranges for safe operation.

 

Despite the specs possibly being within range, there have been studies linked to in other discussions done by Google (?) or other firms (Russian?) that indicated a bell-curve performance ranges. I can't recall the exact ranges and how it affected performance, but it seemed like 30-40 C might have been the sweet spot.

 

With possibly extreme temps between idle and working, I would think you might need to take extra precautions to prevent condensation from having a negative impact.

[Chuck]

I have read that 5º C is minimum, but that running in the low 20's C will shorten disk life (google study).

 

I worry about mine running in the upper 20's when I am watching a movie. That is too cold IMO.

[limetech]

We all know the safe and optimum high end operating temperatures for hard drives, but when is it too cold? I live on the US east coast and right now outside temperatures are in the single digits, sometimes dipping below 0 degrees Fahrenheit. My server is in an unheated store room, and though I am sure that that room is not as cold as outside, it is still pretty darned cold in there.

 

My array was started, but all disks were spun down due to inactivity. Just to read the disk temps, I gave the command "spin up all disks" and the array locked up. I had to shut down very uncleanly (by switching off the power supply) and restarting. When the array came back up, I had a red ball in front of disk5, so I rebooted via the web interface. Now all of the disks are coming up again and all looks well, but I just have a suspicion that the problem is that the disks are too cold and are not spinning up quickly enough in the extreme cold.

 

On the web interface, I have seen temps as low as 9 degrees C. With all 20 disks up and running right now, the average temperature is around 12 degrees C.

 

Is this safe for my array, or is there something I can do to keep things running better during this cold snap?

 

If you look at typical drive operating specs, they have a "mininum operating temperature" which is above those temps.  I have the same problem here in CO.  Once I lost two drives simultaneously    which is not good.  What I do is keep all drives spinning on servers kept in the cold.  Something else effective is to put a cardboard box over the server.

[Oddwunn]

Thanks, guys!

I can't recall the exact ranges and how it affected performance, but it seemed like 30-40 C might have been the sweet spot.

Really? I had been working to keep my disks running as cool as possible. So I should adjust my target range to 30-40 C for optimum performance and life?

What I do is keep all drives spinning on servers kept in the cold.

I just set the "default spin down delay" to "never" in the web GUI settings. Is this all I need to do to keep the disks spinning at all times?

Something else effective is to put a cardboard box over the server.

Thanks, Tom...will do!

[Chuck]

I think it was 35 - 46º C that was the ideal range.

[ohlwiler]

Something else effective is to put a cardboard box over the server.

 

Now that is a great idea. I'm going to give that a try.

[SSD]

I think it was 35 - 46º C that was the ideal range.

 

I think 35-40 was ideal according to that study.  Above 40 was too warm.

 

I think we put too much stock in the Google study.  Current drives are 1-2 generations newer than those, and I wonder if a study featuring current drives might yield different results.  Access patterns for unRAID are also different, which could influence results.

 

I have run my server on the cool side (14-26C in winter. 22-35 in summer).  Never had a drive fail.  I know this is anecdotal, but there you go. I'd much rather take my chances on the cool side, then on the too hot side.  Over the years I've had a lot of issues with heat and none with cold.

 

That said, I do think that servers in the single digits © are too cold.  Condensation definitely to be avoided.  Run your server in conditioned space if at all possible.  Mine is in an unfinished basement which tends to get chillly, but it is conditioned.

 

If you do throw something over the server to keep in warm, be careful.  When the temps rise, you may create worse problems on the hot side.  There was a user a while back that had an overnight guest throw a blanket over his server to cut down on the noise.  Not good!  (Update:  HERE is a link to the thread.  One of the more memorable errors we've seen reported over the years. )

[Blade1001]

Just read this thread; never knew there was a 'minimum' operating temperature for hard drives (obviously other than going silly low, like freezing point).

 

Surely 30-40C is too high for the newer 'green' drives. I have my house at the usual 19-21C, and the WD EARS max out at about 26-28C when in use with just gentle airflow over them provided by the fans in my IcyBox 5 disk backplanes. WD give an operating temperature range of 0-60C which isn't much helpin identifying the ideal.