Disk not ejected properly

Robster50's solution worked for me with a Seagate Free Agent 3Tb drive used with Time Machine on a MBP 5,1. A Monoprice 8 port hub connects the pair. When ejecting the external drive from the Finder, the process is also quicker - no 2-3 second wait for ejection. Thanks!

More info:

After giving up on my Mac Mini Server I tried plugging the external drives into my Time Capsule - Same problem. Although odd I couldn't rule out at this point that the same bug had made it into the latest Time capsule firmware update.

As a last ditch attempt I tried running the external drives off of one of my Synology NAS servers (They have a Time Machine feature built in too). Interestingly I saw exactly the same problem - the drives would be disconnected, but only once I started using them for Time Machine. If I just use them as expanded NAS stores they are absolutely fine!

I am now trying backing up to the internal drives on my NAS, which means I'll have to split all my backups and is far from ideal but right now I'm down to having no backups at all.

This leads me to believe the following, both from my experiences and what I've read so far...

1. Time Machine appears to be the root of the problem, NOT OSX itself

2. Seagate drives (not enclosures necessarilly but actual hard drives) seem to be the most affected. I wonder if this is related to the drive power management styles on certain models (I have another external drive that is also seagate but is fine). I'd be interested to know if drives like the WD Greens are similarly affected.

3. The issue affects network volume mountings as well as external hard drives

I have a theory that if I replaced my hard disks with something like the WD Red drives then I may be better off, but I don't really want to throw any more money at this right now. I'll keep reporting back on the Synology option though, as if this works I'd be tempted to get a dedicated NAS for Time Machine, RAID Mirror it, stick it in a corner and let it just get on with it.

It's not the Time Machine that's the problem, I haven't had mine connected for a couple of years because I work from home and it destroyed the connection with my office VPN (not because of the Time Capsule/Time Machine themselves, but because my employer opted for a low quality of network components).

For the last two days, I turned off the Time Machine software on my iMac OSX 10.9.2 and my Maxtor OneTouch4 external hard drive stayed connected. This morning I tried to run Time Machine manually and about 1/2 through the process of "preparing" the back up I got the message that the drive did not eject properly. In Energy Saver, I have the Prevent computer from sleeping box checked and the Put Hard Drives To Sleep box unchecked. In Spotlight, I have the drive excluded from any searches. All this started when I upgraded to 10.9.2 on 2/26/14. Before then Time Machine worked as designed.

I really think this is a 10.9.2 (some have if from Mavericks earlier builds) issue with the Time Machine software itself. My experiences were similar. It would be interesting to know the spec details of the physical hard disk inside your Maxtor OneTouch.

On a more positive note - It has now been two days since I moved Time Machine duties over to the internal drives on my Synology NAS systems and my Time Capsule - Since then I've had no issues at all. It seems that Time Machine does something wonky that causes external drives to be disconnected, whether TM is running on the connected machine or whether the external drive is plugged in to a network server. If you back up to an internal drive on a network server it seems OK.

It would be interesting to know if this specifically affects USB attached devices or whether Thunderbolt is also affected (although who wants to pay the bucks to run a TBolt drive as Time Machine? A NAS is cheaper!) I may investigate whether my NAS has an eSATA port and see if that's affected as my enclosure has an eSata connection on it.

Unfortunately I don't know much about the Maxtor OneTouch4 hard drive. It is 5 years old and I purchased it from our church to use as a backup on my old PC. When I purchased my iMac, I used the Disk Utility to format and partition the drive to the Mac Operating system. I should mention that the drive is USB connected and the drive end is a "mini". If I can't get this to work, I will look at purchasing a Time Capsule (maybe that's what is driving this anyway).

I tried attaching a drive in an OWC enclosure to my Mac Pro, to see if that enclosure would do any better than my Seagate brand externals that get ejected improperly when the computer sleeps/wakes, and as I expected, the result is the same. Mountain Lion and Mavericks both exhibit this problem, Snow Leopard does not.

Today I installed 10.9.3 update that was just released for OSX today, 5/15/14, with high hopes that the problem had been solved. It was not. Time Machine did one backup but the second an hour later caused the external hard drive to eject.

I talked with the techies at the Mac Computer store where I bought the iMac and they suggested that I completely reinstall the complete operating system.

I just got off the phone with Apple again. The problem was supposedly escalated to Engineering three weeks ago, I have not heard anything since, there is no sign that this escalation actually happened. Now they want to say it's a hardware problem and I should take the laptop in for a diagnostic. I will not be taking it into an Apple provider, I have had it with them.

BTW, some have mentioned that it doesn't seem that anyone at Apple knows about the problem, even though it has so much attention on the forums. I can confirm that Apple tech support pays no attention to these forums. I told the specialist that my problem is not unique to me or my devices, it is happening to many people with many different species of external drive, that it is largely with Mavericks although some have reported it with Mountain Lion. The specialist flat out said that if people aren't calling Applecare with a problem, they don't know about it, that the forums are only for users to have discussions with each other. So the only way a fix will be found is if people start bugging Applecare with it.

I was on the phone with an Apple Tech and his supervisor. After a ejecting and re-mounting the drive, it stayed connected for at least 2 TIme Machiine backups but then it self ejected. They think it is the USB 2.0 cable that I have on the External Hard Drive. I will need to find a USB 3.0 with a "mini" connection to the hard drive and a standard one to the iMac. I will give it a try. At the same time they had me mount a USB Flash Drive and it stays connected, but of course it was not being used by the Time Machine.

I decided to try unplugging my Seagate from the USB3 drive on the back of my new iMac running Mavericks and plugging into my USB2 hub instead. So far it isn't ejecting my Seagate anymore. It has gone to sleep three times and awoken three times without ejecting. I will repost when enough time elapses to see wether or not this is a real fix.

This is an addendum to my post above. I hope it helps someone out there, because it does look like it solved my problem.

I just talked to an actually very helpful senior advisor at AppleCare, Allen. He said that the reason my Seagate backup drive is not being ejected improperly every time my Mac goes to sleep, now that I have the Seagate plugged into my USB hub instead of directly into the USB port on back of my iMac, is that my USB hub has its own power source. The USB powered backup drives that don’t have their own power source (like mine) have drivers that tell the device to go to sleep when the computer goes to sleep, so they won’t be drawing their power from the computer while the computer is sleeping. When the computer wakes up, the backup drive doesn’t wake up quickly enough; therefore, it ejects. So, connecting a backup drive to a powered USB hub is a perfect workaround. I can’t believe I actually thought of trying it. It worked, but I didn’t know why until I talked to Allen at AppleCare. He said the only other workaround, until Seagate & some other manufacturers come out with a new driver to solve the problem, is to manually eject the backup device before putting the computer to sleep and unplug it; then, plug it back in before waking the computer back up …which would be a royal pain!

Unfortunately this won't help me. This is happening with my iPod and my flash drives the moment I plug them in. It has nothing to do with the computer going to sleep because they aren't connected to the laptop when it goes to sleep.

I bought an external power supply for my OWC drive and it didn't solve the problem. The problem lies in

the usb 3 programming I think. I think using a usb 2 hub might work ok though. I may try this later and see.

John

Definitely not limited to USB: Mountain Lion and Mavericks improperly eject my eSATA externals, too. It's like Apple added a mean, incompetent bouncer to the OS after Snow Leopard.

BTW I don't have any bus-powered drives in use with the Mac Pro, and it happens regardless.