External hdd won't eject properly since El Capitan

It seems like my ejection problem is solved. My USB3 external drives would not eject after upgrading to El Capitan. But, on a whim, I upgraded to a USB3 hub to see if that might help. Low and behold, it worked! My USB3 drives now eject when I put the computer to sleep. I'm not sure why, however, the USB3 drives ejected through a USB2 hub in Mavericks and Yosemite, but not in El Capitan.

This was the exact right answer for me. Thank you.

I am also having this issue with my Macbook Air 11" and my late 2015 iMac 5k, both running El Capitan. My USB drives either refuse to eject and give me an error that says something like "This drive couldn't be ejected because it is in use" or the drives take an extremely long time to eject. I get these errors even if I connect and try to disconnect a drive immediately after starting up the computer with no applications running.

-Derek

I Changed the spotlight privacy settings as described earlier and try to remember to pause google drive and dropbox syncing and it seems to have stopped my problems with ejecting my USB drives.

I have updated the spotlight privacy settings and used Activity Monitor to kill all instances of mdworker to no avail. I am able to eject the FAT formatted partition of my external drive, but not the Time Machine partition. Resetting the computer with the drive attached (and then resetting again from recovery mode, since the drive is a Time Machine drive) seems to be the only way to eject it safely. This has been an issue since October -- does anyone know anything about updates in the work for this issue?

I am having this issue with a lot of the USB 3 drives I plug up to my new iMac 5k (late 2015). None of the drives are Time Machine drives. They are various Seagate and Western Digital external drives, formatted for Mac. I have no programs running. Occasionally Spotlight won't let me even select the drive in the Privacy Preferences.

El Capitan is really buggy. I am a media professional that mounts and dismounts drives in an editing bay all day. This is such a huge pain right now.

A bump to this thread. I’ve got 11 external drives that I use with two Macs, and I’m fed up with having to force eject them. I did not experience this in the early going with El Capital; it is a very recent phenomenon for me. As for some of the fixes mentioned, I use a USB 3 hub and that doesn’t help. I don’t want to have to reboot to accomplish something that shouldn’t be a problem, and I want Spotlight to search all of the disks.: at least 90 percent of my files are on the external drives. The phone company is not doing a great job with the software of its tiny computer division.

PS. I’ve added one drive to the Spotlight exclusion list, but it still won’t eject without force.

I have a USB 3 hub, and it doesn’t prevent this problem. And how would that be a solution anyway. A hub should be totally unnecessary for proper Mac function.

I had the same issue (also with Western Digital HDs), on two Macs. But then I found that if I waited long enough, the problem resolved itself and I was able to eject the HDs. I don't know if it's due to Spotlight finishing indexing, which would take a long time for backup drives.

Just stumbled across this issue after upgrading to El Capitan. I force ejected an external disk and it became corrupted - would not mount properly and causing hang issues when it did. I used CyrilC's sudo commands ( Link to this post ) to suspend Spotlight to get clean ejections. Easy workaround, but should not be happening.

This worked well (or so I thought) until I had to unlock my screen after stepping away from a few. Issue popped right back up. What a annoyance... you had me excited though! thought it was finally resolved. Bummer...

mattrock1: any solution thus far are transitory. Setting Computer Sleep to "never" in System Preferences / Energy Saver might help, as many external disk protocols like SAS and eSATA have issues with being abandoned when sleep is invoked. Long standing problem for OS X.

Like the rising sun, greets on every wake...😐

Going to give this a try as well. Thanks!

Thanks Cintos. I've done this a while back (which goes against my energy-saving mindset and feel like a hypocrite as I try to enforce energy saving measures on my family). Unfortunately the problem persists. Though intermittent it seems (when it's bad, it's bad. Then tends to disappear for a while...) I appreciate the help though. It's likely a step in the process for others experiencing the same.