Drobo iSCSI **DOES NOT WORK ON 64-bit MAC**

I just had this confirmed by drobo. Their iSCSI driver, even though listed as WORKING in their knowledgebase, does NOT work on a 64-bit Mac kernel. Since Mac Server boots, by default into 64-bit mode, that means that drobo does NOT work on Mac Servers.

They’re “rewriting” the iSCSI driver – no ETA. But, it’s been a KNOWN issue since day-1 on 64-bit Macs. That’s almost 2 years ago…

hmmm, they arent very good at keeping the list of “known” and “fixed” issues up to date!

Can U be a little bit more specific abt "does NOT work on Snow 64-bit Kernel? Are U experiencing performance (just slow), random disconnections, data & volume corruptions etc…
We’ve been using the DroboPro/DroboElite for over a year for block-level backups & archive iso images & VMs but only under MS Windows Servers 64-bit & VMware environment and so far so good - Well, they are the fastest iSCSI SAN but for our intended purpose, the Pro/Elite does serve our need.

[quote=“rambo, post:3, topic:2155”]
Can U be a little bit more specific abt "does NOT work on Snow 64-bit Kernel?[/quote]32-bit kernel extensions (under OS X) will not work when running a 64-bit kernel.

If Drobo’s iSCSI layer is using a 32-bit kernel extension, the SAN will not work. Furthermore, I suspect that a Mac running a 64-bit kernel with a Drobo connected only through Ethernet, will actually not even recognize its Drobo hardware.

OS X supports 32-bit and 64-bit iSCSI, but it requires a iSCSI Initiator. For Drobo, the initiator is Dashboard and there is no 64-bit version of Dashboard.

32-bit ketxs (kernel extensions) will not work with 64-bit and vice versa.

It will work it is just unbelievably slow. Less than 1Mbps speed, usually closer to 200 to 300 Kbps.

It is easy enough to see the slow transfer speed if you have a program to watch your ethernet connections, something like iStat.

I ran some stats for Drobo support… In 32bit mode, I was about 80mb/sec for both read/write. Worked great.

But, when I booted into the 64bit kernel, I got 80mb/sec writes, but 1mb/sec reads. And, after a while, the drobo became unresponsive… Basically, reading from the drobo on a 64bit mac os fails miserably. 1mb/sec isn’t even in the ballpark of reasonable IMHO.

For the sake of keeping this accurate; Drobo has an updated .plist that will fix this issue. Installation is a bit dicey, but, it will solve it.


I’m curious as to how you did this.

e-mailed support one would imagine…

How I installed the new plist? or how I got it?

I emailed my contact at Drobo, and was given the file.

As to how to install it… As I discovered, you need to copy the file over inside of terminal as root. Otherwise, the permissions/ownership is all messed up. (Originally, I thought it wasn’t working as I copied it by drag/drop… Tried it again as root via. terminal and it worked.)

It goes into the drobo driver; not the app.

After the new plist was installed, the drobo works just fine on my macmini server. :slight_smile:

Very interesting. Thanks for the info.

Hopefully the fix makes it into the next firmware update. If not then I suppose I will be emailing Drobo support for the fix.

I’m not afraid to use Terminal, but I would really want some detailed instructions before I tried this myself.

Gosh. This would have saved us a lot of trouble. We’ve actually had our 2 DroboPros changed by Datarobotics after tests showed the poor read speeds (<1MB/s) only to have exactly the same problem with the new units they shipped us.

We spend hours checking and testing all possible configurations, looking for hardware problems, etc. but to no avail. Ended up using FW800.

We did mention we were running on an XServe/Mac OS 10.6 Server, but they didn’t pick up on that.

Thanks for the info - looking forward to a fix as the hardware was purchased explicitely to use the DroboPros via iSCSI on an XServe (as advertised)…

I posted directions on making the drobo work under Mac OSX 64-bit, over here: http://www.drobospace.com/forums/showthread.php?tid=2035

I’m having the same disconnect issues, but it has accelerated to the point of crashing the entire server. Hard crash, wherein the power manager detects the server has crashed with no response and power cycles the chassis. OS X 10.6.6 XServe, 64-bit kernel. I tried the plist as linked above and found that one of the eight DroboPros attached mounted and the other 7 were AWOL.

It runs great when it runs, but if it decides to stop running it tanks hard.

I’ve been talking with Tier3 support about what I think is the exact same issue (drobo locks up Final Cut / Finder / everything) over iSCSI on my brand new MBP, but not my C2D iMac. I’ve been ripping out my hair, and I really hope this is the answer.

previously (back in august 2010) i had asked them whether iscsi was supported on 64-bit kernel. i reported some problems i was having and i got the “official” response from drobo support: “This issue was corrected with Drobo Dashboard updates. The DroboPro is functional with Snow Leopard in 64-bit mode when connected via iSCSI.”.

i tried again to make it work it and it was a dismal failure (corrupted volume - forced me to complete reset the unit and start over).

so i re-asked drobo support about this again yesterday and today i got a response from drobo support on this: “The ISCSI Initiator that is installed with Dashboard still has issues with working in a 64 bit environment. Our Engineers are aware of this and are working on a fix. They have not released an ETA yet.”

thats not great…

It would be appropriate for a Data Robotics rep to respond to this thread. Three months of silence on their own message board doesn’t look at all good.

I’ve actually switched to GlobalSAN iSCSI – what a difference! Absolutely amazing difference in speed and stability.

Get the initiator here: http://www.studionetworksolutions.com/products/product_detail.php?pi=11

Make sure you totally remove the drobo dashboard, reboot, then use the new initiator.

Not sure if it’s appropriate, but, I’ll post it anyways… If you want a professional install of the iSCSI (I’ve been in the computer industry for ~15 years as a professional… I’m MCSE, but I’m good with macs too :slight_smile: ), I can do the install/switch remotely. Email me/PM me for details. David@WolfSnap.com