Sometimes we get fixated on specific settings and possibilities when troubleshooting problems with our Macs, and in doing so might overlook other seemingly unrelated settings that might end up being the root of the problem at hand.
Recently, MacIssues reader Graham wrote in, asking about a problem with his Thunderbolt drives unmounting at random intervals:
“I bought a LaCie 2TB (2 disk) drive last week and several times it reported that it was not ejected properly…I moved up to a WD 4 TB My Book, again Thunderbolt connected, but when it also reported a failed eject, I repartitioned into 2 disks and just left it connected. I came back a couple of hours later and once more – Failed to Eject properly. I tried different ports. I wiggled the cables while connected but this did not indicate any weakness. I am guessing power saving may be a problem, but USB (2 and 3), Firewire 800 (with Thunderbolt adapter) do not show the same problems.”Spontaneous ejects of external media happen when there is a severing of the connection between the drive and the computer. This can happen from the use of faulty cables, incompatibilities between daisy-chained devices, and improper power management for attached devices.

The functions managed by these settings may cause similar Thunderbolt-related problems on some Mac systems (click for larger view).
To tackle this problem, Graham noted that using a Thunderbolt-to-FireWire adapter does not cause drives to eject, and since this uses the same Thunderbolt port on the computer, it was unlikely that the cause was from power mismanagement. Instead it pointed to either the Thunderbolt cable or a problem with how the Mac is handling Thunderbolt connectivity.
Upon trying a new Thunderbolt cable, the problems persisted for Graham, and it looked like the obvious solutions were not applicable in this case. While further troubleshooting might have gone in the direction of reapplying updates or reinstalling OS X, our discussions regarding power to the devices had Graham try toggling some of the system’s Energy Saver settings.
In the Energy Saver system preferences, you can check the option to put hard disks to sleep when possible, or enable power nap on systems that support this feature. Graham found that by checking the option to prevent the computer from going to sleep when the display is off, the problem no longer occurred.
While this is not a fix for the problem, it does at least keep it from happening, and allows the system to work without ejecting attached drives. Another possibility is that this error is related to a faulty System Management Controller or PRAM settings, so resetting the SMC and resetting the PRAM may help for others who experience similar issues. Otherwise, hopefully this type of error can be fixed in a future update to OS X.
Graham has written an extensive report of his drive troubleshooting on his blog.
I don’t think it has anything to do with Thunderbolt’s DisplayPort channel. The issue is simply computer sleep.
Energy Saver used to have separate settings for time until display turns off, and time before computer sleeps due to inactivity. But with newer Macs (specifically, Haswell cpus) there is only a single setting for display sleep, as shown in the Preferences image in this article.
So, the “Prevent computer from sleeping automatically when the display is off” setting is controlling whether the computer does idle sleep at all. Either the computer sleeps when the display turns off (and there is nothing asserting that it shouldn’t sleep), or the computer does not.
There are rumors that the root cause is Mavericks Thunderbolt driver issues (see MacIntouch).
Certainly it’s a good idea to check related settings – if you can figure out what they are. Figuring them out got a bit harder with OS X 10.9 Mavericks since Apple moved some of them around. This can be tricky if, like me, you have to support multiple versions of OS X on clients’ computers.
In a related note, I’ve been trying to figure out what security settings or Safari extensions have been preventing me from posting here: It appears to be the “Don’t track my browsing here” setting in DoNotTrackMe in conjunction with JavaScriptBlocker – which, not incidentally, block the adds on MacIssues as well. I guess it’s no longer possible to put adds on a web site that don’t use analytics and tracking cookies. It’s reasonable for advertisers to want to be able to evaluate the effectiveness of their banners. Whether such statistics give them any really useful information is debatable. In the meantime, do we automatically and inevitably give up our privacy when we venture onto the Web? If we decide not, and take steps to provide for our own security, it appears many web sites block us out of hand. There may be, therefore, no alternative to using at least two web browsers: one for secure web surfing and another for participating on blogs. Though it’s worth noting that not all blogs block me in Safari: The Adobe forums, for example, do not. But then they don’t post adds, either. I don’t object to web sites like Macworld and MacIssues using advertising to pay the bills. There’s no free lunch. But allowing those adds to track me goes too far, in my not so humble opinion. I suppose Topher has no choice but to allow his advertisers to scope out his readers, but that doesn’t mean we, or at least I, have to like it – or permit it when it can be avoided.
This is not the only site that curtails access if you take the trouble to guard your security – Macworld.com does so as well. So, I can either turn off major security features in Safari or use a less secure browser when I want to post. I’ve been doing the latter, with Chrome, while thinking through the problem. And that may be my final choice – between convenience and security. These days it seems to me security is probably more important than inconvenience. Though I expect I’m in the minority in this opinion. Most people don’t worry about security until something goes wrong. These days, however, things appear to be going wrong at an ever increasing rate.
By the way, the security measures I employ do not prevent me from doing business on most banking and e-commerce sites – though Sears.com appears to be an exception to this rule. But news sites like this one having trouble monetizing their product so they seem to be particularly vulnerable to the machinations of advertisers. They probably they have little leverage in the matter.
After all this, just getting adds on this site to show up is not enough to unlock posting via Google+. I’ll try turning off all the DoNotTrackMe settings and see if that makes any difference.
No, that didn’t help. Let’s try turning off ClickToFlash. Butkis. Now I’ll turn off all Safari extensions. Well, that didn’t work either. One more thing to try – turning off pop-up windows. If you see this post, that worked. By the way, I reloaded this page between each experiment.
PS: Maybe it was pop-up windows all along. Now I’ll try turning all my security measures but pop-up window blocking on and see it that was the only thing causing the problem. I have now spent several hours troubleshooting this issue. To bad I won’t get paid for my trouble. If you see this post, then pop-up windows was the issue.
The unwanted unmounting of drives (SCSI, USB, Firewire) is nothing new, it goes years and years back regardless of OS, computer or drive model, or whatever. Not surprised then, if Thunderbolt is now also giving problems. There are threads dozens of pages long on the Apple Discussion forums. Many people there have found work-arounds… that didn’t work for others.
Yours truly has found peace of mind by 1. using cables as short as possible on the Firewire chain; 2. not plugging into the keyboard’s USB ports any device that doesn’t have its own power supply; and 3. giving up on trying to figure out why one particular machine will spit out about any CD, whether it’s inserted in the internal or in an external drive.
But I doubt that these solutions would be the right ones for everyone.
I had same issue with WD Passport Pro portable bus-powered RAID, had to send it back. I also spoke to LaCie tech support who were hearing same thing with their Thunderbolt drives. Both WD, LaCie … and everyone else, IMO, point to Apple. Some blame SSD drives for powering up too fast and not giving external TBolt drive time to communicate, before declaring it “ejected.” Whatever the case, it doesn’t seem to be hardware (I tried two replacements before giving up) but Mavericks Thunderbolt issue.