I have two 2nd Gen Drobos daisy chained via firewire 800 to a mac mini.
Recently I’ve noticed that the one NOT connected directly to the mac is disconnecting at will and, it would seem, randomly.
When this happens, any program accessing the drobo, such as iTunes, will hang and need to be force-quitted. Also, the Mac will not shutdown or restart without the power button being physically pressed for a hard shutdown.
I’ve also only recently had the need to leave the mini powered on for a few days without powering down, which could be why I noticed it happening now and not earlier.
Both drobos, mac and drobo dashboard are using the latest firmware and software.
Both drobos have 4 x 1.5TB Western Digital EADS drives.
If you don’t have a spare cable try swapping the cable between the two Drobo units. If the cable is dodgy then both units should drop off as the cable would then be between the first Drobo and the computer.
It makes sense, but I doubt it’s the cable as the unit returns to normal after a reboot of the mac, without me physically touching anything other than the mac’s power button.
Also, since my post, I seem to have narrowed the problem down to multiple files being written and read to simultaneously.
I recently started using an application that does this, and thinking about it, that’s when the problem began. In fact, I’ve since drastically limited the number of files that are being accessed simultaneously, and so far have not had any problems - it’s been 48 hours give or take now…
I’ll eventually slowly increase the file number to see at what point the drobo hangs.
Still, if this is indeed the cause of the hang, i doubt it’s normal or expected behaviour… or is it?
I agree that you should replace your cables - firewire 800 cables tend to be quite stiff and place a strain on the connectors.
I’ve found that the orange LaCie cables work really well - they’re flexible and tend to not place a great deal of strain on the connectors.
Strain over time can do weird things to materials - I have a MacBook Pro 17 (early 2008), and over the years the Kensington Security Slot lock which I use at work (steel) has eaten its way through my MacBook Pro’s aluminum slot so that it doesn’t provide security any more - it can be worked out without unlocking the lock.
Drobo’s Thin Provisioning (the thing that lets it look like a larger than the physical storage) is done solely in the hardware. Drobo Dashboard is just for changing settings, email alerts, pop-up alerts, and the usage graph.
It’s definitely convenient and useful, but not required for normal Drobo operation.
As you can see here http://www.drobospace.com/forums/showthread.php?tid=969
the speed of the Drobo is different depending on how much rest the Drobo had. Pay special attention to the note halfway down: “Note: It is very important to let the Drobo rest after format, and probably after writing large amounts of data. I did not even reach half the speed when I started writing directly after format.”
I’m not sure what it is doing, but it might be some internal defragment and/or relayout process. This is NOT shown by any LEDs at the Drobo but you will clearly hear the drives working. I would give your Drobo a day or two to rearrange the data and then make your tests again.