Temperature Threshold for Fan Switch On ?

Even when my Drobo v2 (FW 1.3.5) is idle (Mac switched off, all Drobo lights off), its fan regularly switches on. The Diagnostic log then tells me my 4 drives are at or below 35°C.
What is the temperature threshold for the fan to switch on ?
Are there other events beyond drives temperature to make it switch on ?
The periodic fan noise is not a major problem, but it is irritating since everything else in my Home Theater is totally quiet…

how can u check the temperature in the diagnostic logs?
i’m having the same issue… no data is being written or read from the disks yet the fan is almost always on

  1. Get a fresh log immediately when the fan starts running using the Drobo Dashboard
  2. Decode the Drobo Log (search Forum to see how)
  3. Search in the decoded txt log for the last/bottom : “Last Drive Temperature”
    There is also a timeplot found by searching : “Max Disk Temperature”

This answers your question, but my basic assumption at that time was wrong : most of the heat does NOT come from idle low consumption disks (I have 4 Western Digital Caviar Green WD20EADS which use at most 4.4W total when idle), it comes from the Drobo electronics itself which even with idle disks draws more than 10W : check the Tech Specs on Drobo.com.
It is even worse for Drobo-S, which unsurprisingly is noisier than Drobo-V2.

Sad that Data Robotics forgot the noise lesson they learned from Drobo-V1 to Drobo-V2, and came back to square one with Drobo-S.
This noise issue is the main reason, in addition to the ridiculous price increase, that I did not upgrade from Drobo-V2 to Drobo-S.
Data Robotics is so focused on the (presumably more profitable) professional market that they forget most of their “prosumer” customers have their Drobo in the living room and care A LOT about the noise, especially when idle.

I’m not able to decode the logs, I dno’t know why. I get an error on the php file.

I’ve contacted support… this is getting quite annoying.
The drive’s aren’t being accessed at all and the fan is at med speed. and the room i’m in is cold.!!!

If you are running on Mac OS X with Ruby pre-installed, you can use the script given at forum.nas-central.org.
The script must be stored at :
Then call it typing in Terminal :
ruby /Library/Ruby/Site/1.8/svn/drobologdecrypt_neil.rb “/your_log_path”

But anyway, as I explained before, the fan running at low speed too much is unfortunately “normal” from Data Robotics point of view. Only if the fan was running full speed when the Drobo is idle could you presume something wrong.

I’ll give it a try.

It’s not running at low speed… when it does run at low speed I can barely hear.
It’s running either at medium speed or the second top speed…

I’ve had the unit for 6 days… and i’m considering returning it.
DR should release a firmware to fine-tune the fan…

If you really need to make the fan work due to the electronics in the drobo, at least use a quiet fan !!! :([hr]
This doesn’t make much sense at all: I just placed the drobo inside a cabinet and in there it’s not making any noise at all, the fans are off. Since the cabinet is a close space in nature, it puzzles me how can the drobo be cooler inside a close space as opposed to exposed to cold air on top of my table.

Guys, Try replacing the fan. It will make you forget about your (slow&noisy) Drobo.
Next time your in for a storage solution buy something else.