External hard drive ejects on sleep

I had just this problem with my Macmini and two identical WD external hard drives, one with two partitions kept ejecting and giving the unplugged message. I deleted the second partition and that fixed the problem.

Is it a network drive? I know that internet disconnects on ML which never happened in lion before.

If you cannot resolve your problem consider an App called Jettison (available in the Store) which gracefully ejects external drives before sleeps and then re-mounts them when you return.

Cripps said:

If you cannot resolve your problem consider an App called Jettison (available in the Store) which gracefully ejects external drives before sleeps and then re-mounts them when you return.

Click to expand...

Does it remount also when the ATV wakes the computer, i.e. not logging in as one would normally do?

After sleep my mounted network disks are gone - Mountain Lion. Have to re-mount them again. In Lion it was all fine. Will send a ticket to Apple - this is a bug.

On mine as well. Sleep ejects the drives so well, the system cannot see them when it wakes.

Jettison has no affect on this and my backup software will no longer work as when it wakes the system the drives are gone.

Pretty serious defect.

Just put my MB into sleep with an external connected. It was mounted when I woke the machine up.

No issues here.

Not so on my retina mbp

I have two external hard drives hooked to both my iMac and Mac-Mini. Not seen the eject after wake from sleep issue using Mountain Lion. I use firewire 800 connections. People having the issue what connections are you using? Wonder if a particular port is related to the issue (e.g. the second USB from the left, etc.).

Taz Mangus said:

I have two external hard drives hooked to both my iMac and Mac-Mini. Not seen the eject after wake from sleep issue using Mountain Lion. I use firewire 800 connections. People having the issue what connections are you using? Wonder if a particular port is related to the issue (e.g. the second USB from the left, etc.).

Click to expand...

I'm using USB 3.0

Well, considering that OS X ejects all external drives when it goes to sleep. It makes sense that your external hard drive would eject.

Icy1007 said:

Well, considering that OS X ejects all external drives when it goes to sleep. It makes sense that your external hard drive would eject.

Click to expand...

That's not the issue - the issue is the drives not remounting.

My external drive (and others in this thread) works fine on Mountain Lion. However, it is not partitioned. I guess partitioned drives are where this bug is occurring.

jason221 said:

My external drive (and others in this thread) works fine on Mountain Lion. However, it is not partitioned. I guess partitioned drives are where this bug is occurring.

Click to expand...

My drives are partitioned. I'm not going to repartition just to see it if it works. I don't that's it. I think it's a USB 3 issue.

jason221 said:

My external drive (and others in this thread) works fine on Mountain Lion. However, it is not partitioned. I guess partitioned drives are where this bug is occurring.

Click to expand...

I can reproduce the problem every single time if I wake my computer by accessing the iTunes library from an iOS device. Waking it up from sleep and logging in sometimes remounts the drive, sometimes not. It's not partitioned.

I might be having a similar problem.

I have 2 drives in a new USB 3.0 dock. One of the drives has two partitions, the other one has one partition.

With the two partition drive in particular, I have one partition as a time machine backup. Often (but not always), when I go away for an extended period of time, Time Machine reports that it couldn't backup because it can't create a directory.

Looks like the drive was ejected. I get the message, "disk was improperly ejected".

I have the laptop set to never sleep.

For a while I thought it was the option to let the drives spin down. If I set that off, it seemed to fix the problem. But sometimes even with it set on, and the drive spun down, it works fine.

I've been off on a tangent thinking maybe the drive was overheating in the dock. I had the other drive eject as well even though it has one partition.

I put them back in their previous USB 2.0 case. I discovered using S.M.A.R.T. that the drives run even hotter there so that's likely not the cause of the problem.

So now I'm down to thinking its either a USB 3.0 issue with the Macbook Air or with Mountain Lion, or an issue with the USB 3.0 dock.

I also had a situation where USB communication suddenly stopped. The Macbook was still running, but if I ever asked any app to do anything with the file system, it would hang. Eventually the whole machine was hung and I had to hard power off.

I am also having this problem on my headless Mac Mini which has 2 x FW800 drives attached. When it goes into idle sleep (not manual) the drives do not re-mount. In fact I have to manually power the drives off and back on again for even the Mini to see them again !

Does the latest ML patch fix this issue?

Just an update:

10.8.1 does not fix this problem.

Also, the problem is related to hard drives connected through a hub. I have a USB 3.0 hub and according to plugable (the maker), ML does not properly interrogate the hub to determine that there are drives connected. This hub worked perfectly under Lion.

The apple forum has several threads on this issue with no clear idea when Apple will fix.

If I plug my drive directly into the computer it reconnects properly from sleep.

I'm having the same symptom with one particular USB drive on my new iMac with OS X 10.8.1. It does not make any difference whether the drive is connected directly or through a hub. I had no problem with this drive on my previous iMac with OS X 10.7

I opened a support case with Apple about this and have spent several hours talking with a senior advisor from Apple, trying this and that and that and this and sending them twice captured data from my computer. Nothing helps. I'm waiting since August 25 that Apple calls me back after having sent them another set of captured data.

I've been having the exact same problem since purchasing a MBPr and a USB 3.0 Seagate 1TB external HDD a couple of weeks back. It's intermittent and not always the same. HDD plugged directly into MBPr with "Never Put Hard Disks to Sleep" seems to be the best configuration so far for the least amount of HD ejecting faults.

In general, whether I plug it into a 4 Port 'Trust' USB 3.0 Hub, or into the MBPr directly, it ejects on sleep and only sometimes mounts on wake. When it doesn't mount again I always get the "You didn't eject a device" nonsense on wake.

I've also returned to my machine whilst it's still fully awake, just a couple of times, to find the drive missing from the finder/desktop but no warning message re: ejecting the drive, and the physical HD still powered and spinning.

Other than the fact it's annoying and time wasting, I'm worried all this connecting and disconnecting malarky could do damage to the drive or the data before its time.

We're now at 10.8.2 and it's still a bug. Apple don't seem bothered by this - quite serious - issue with their OS!

just starting having this same issue here.

it seems that "sleep" stops all running processes in ML also. its becoming SO ANNOYING!!!

Happens occasionally with my new Mac Mini running Mountain Lion, external is a G-Drive mini powered by the Firewire connection, where it is daisy-chained off the G-Drive with my Time Machine. I will switch the order of the daisy chain so the mini drive is first and see if that makes any difference, though this seems to be a wider problem than could be explained by that.

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Okay, I switched the drives so the unpowered mini drive is first and the powered drive second. That's worse! Upon waking from sleep, both were ejected, where before only the mini drive was.

Next: get a power adaptor for the mini drive.