External Drive keeps disconnecting

I am having the same problem.

MiniMac Core 2 Duo running Lion

WD 1tb HDD, connected via usb and powered

everyone once in awhile the HDD kicks off and states that the HDD has been incorrectly disconnected and that I should property shut down the USB prior to unplugging. It then reconnects by itself.

I am worried that this is going to fry my HDD at some point due to improper shut downs over and over.

I'm also having the issue of drives disconnecting.

It happened today (first time) with my ipad 1st gen when i was moving stuff to it.

It has been happening with my WD drive serving as my Backup for quite a while now (not sure when it started, but I haven't been able to keep my drive connected for more than a few minutes at best. But I do have another WD drive that is connected just fine.

I tried Keep Drive Spinning tonight, and shortly after I set it up to keep my Backup drive active, my drive crashed. Does anyone else have an idea of what's going on?

I wasn't having this problem at all until yesterday, when I updated my 2011 Mac Mini to Lion 10.7.3.

Now, the symptoms described elsewhere on this thread are occurring persistently; the drive disconnects, prompting a popup saying the disk wasn't properly ejected and that the Time Machine backup couldn't complete. It's a 3TB WD.

The drive works fine (i.e. doesn't disconnect) when connected to my MacBook Pro. This is runnning the same version OS (updated this morning).

There are four USB ports, only three are used; one's got a webcam (rarely used), another has the iPhone/iPad connector and the third runs the external HDD. It's been setup like this for months and there hasn't previously been an issue.

Is your external USB drive powered via the USB cable or does it have its own power seperate power supply? The Mac Mini (and others) can only supply 500mA (half an ampere), where as a typical hard drive takes at least 700mA (3/4 ampere). That is for a 2.5" drive. A 3.5" drives takes a lot more! So if you are running a 2.5" drive powered from the mini, it will overload the USB power, which should, after a while cut out to protect itself. You may need either an externally power hub, or a diferent caddie with power supply.

I don't want to jinx it but I tried something last night -- and for the first time in more than a month, my WD MyBook didn't disconnect abruptly.

Seeing how the problem was likely power related (with the Mac Mini being super efficient and low powered), I went into the Energy Saver settings and pushed the "Computer Sleep" scale all the way to NEVER.

The Mac complained, saying how this would significantly increase my energy costs, blah blah.

But guess what. It worked. Not a single disconnect in about 12 hours.

Let me know if it works for you.

Thanks for the tip Alan! 🙂

I just started seeing this same problem in the last week. '08 Mac Mini, 10.7.4, 1 TB WD Caviar Black with it's own power supply (not bus powered). Not running a hub and it happens to be the only USB device connected. Using this drive exclusively for Plex media storage and it is 75% full (approx. 250G free). I have the computer, display and drive set to NEVER sleep in Energy Saver. Disk Util says drive is fine, but with constant disconnects I fear it's shortening it's lifespan.

Try an app called Keep Drive Spinning. I did this 6 months ago and have had no problems since.

I've had the same thing happen with a USB 2 drive on my iMac. A couple of days ago it started just disconnecting. I figured the drive was failing so I reconnected it and tried to copy off some files. After about 3-5 minutes of copyimg, it would disconnect. So it is not a "drive going to sleep" sort of problem.

The drive is AC powered (not USB powered). I even tried switching from the USB port on the back of the iMac to the on on my keyboard but the same thing happened.

For grins, I hooked it up to my 11" MacBookAir and it seems to work (both iMac and MBA are on Lion) So now I am slowly (as the MBA is WiFi only) copying off files I need, keeping fingers crossed.

Similar issue with two 2TB Hitachi Touro Desktop USB drives. I have them connected to a Mac Mini Server 10.7.4 and using them for Time Machine backups. Drives disconnect when idol (apparently). When a backup is commencing, I do not beleive they disconnect. Engery preferences are set to never go to sleep and never [put hard disk to sleep. I do not believe this issue was occurring in 10.7.3 but not certain. I looked into console logs for some clues to at least search forums for some answers. I am going to try Keep Drive Spinning as a test. It's not the drives, cables or power supplies, because I connect both overnight and both dropped off. I have tested both drives and they are OK. I am hoping there is not an issue with the Mac Mini itself (new server with 2 x 750 drives mirrored). I have had a similar issue with a Mac Pro Server 10.7.4 and a Lacie STARK USB drive but being a Lacie drive, I suspect the drive.

I was having this problem. Tried all of the above as well as making a new library on the same disc. Found that the disc could not be written to. Simply force ejected and remounted.

Seems error 13014 indicates that the drive cannot be read or written to for whatever reason.

I have the same problem, but only since I have a new iMac OS X 10.8.2

I have a he PROMISE SmartStor DS4600 4-bay Firewire/USB/eSATA RAID solution, with 2 Seagate Barracude hdd 2TB each; it is connected through USB. It is AC powered.

Several times a day I get this message that the drive is not correctly removed and it disconnects itself.

I am experiencing the same problem with a 2012 Mac mini which has only had OS 10.8.2 (though there has been more than one version of OS 10.8.2) on it. I am using a Firewire 800 drive which has its own power supply. Whenever the mini sleeps it is more likely than not that there will be a warning window that the drive way not properly disconnected & etc. The drive does not appear in either the Finder or Disk Utility. I have to power cycle the FW800 drive in order to bring it back up.

I tried changing the setting to not sleep the mini and it appeared to keep the drive properly attached, but I did not try it long enough or frequently enough to be absolutely certain that doing so avoids the problem.

I filed a report with Apple.com/feedback some time ago which probably was a waste of time, but Apple's people keep swearing up and down that all those reports get read and bla bla bla.

I also spoke with one of the Geniuses at the Apple Store and he said "it is not a known issue". Yea, right.

This solution worked for me:

I ran an app called Keep Drive Spinning that runs for a quick second to "hit' the drive to keep it awake and the problem went away. It can be found at MacUpdate's site.

The problem is worse than ever for me now after the 10.8.3 update. I'm continually seeing the drive disconnect, losing all my sidebar shortuts and any open work i have from off the drive. Keep Drive Spinning was working okay under 10.8.2, but not now.