Backup disk disconnect

[fielker]

I use a G-DRIVE mobile external HD for Time Machine backup. Recently it keeps disconnecting, the icon disappears from the desktop and a message appears saying the disk was not ejected properly.

 

[Slydude]

Which specific G-Drive is this? Can I assume that it is connected via USB? If so check the data cable connections and make sure they are secure. If it uses a cable with two connections to the computer make sure both are connected. If you have another cable try it. That might be difficult though if it is a a special cable

Some of their drives seem to be a bit picky about which USB ports are use on a Mac. See these troubleshooting steps for suggestions. Which specific Mac are you using? Some do not seem to put out enough power for bus powered drives to function properly.

When the drive mounts does it stay connected long enough for you to verify the Disk ub Disk Utility?

It sure sounds to me like the drive is not getting sufficient power consistently. This is a known problem with some bus powered drives when used with Macs.

 

[fielker]

Disk utility tells me the ext HD is corrupt, though I'm not sure if that's because it kept disappearing as it was checking! However, I've replaced it with another, which is now backing up from Time Machine. Thanks for your help.

 

[Slydude]

You're welcome. If you have a Windows box to test it with or know someone who does the drive might work for them once it has been reformatted. Some bus powered drives do not play nice with Macs but do with Windows.

The drive corruption could have occurred due to disconnects while you were checking the drive -- especially if Disk Utility was writing corrections at the time. It's just as likely to have occurred during one of the other disconnects when Disk Utility was not open.

 

[fielker]

It's been working well for some years, and this problem has only occurred recently. But there's only a USB cable to the computer and no power cable, so presumably it gets it's power via the computer. Next time I'm at the Apple store where I purchased it (in London) I'll take it in.

 

[fielker]

Further problems with the new drive, so it must be the USB port that is faulty. I knew another port was dodgy, so I plugged the new drive into the port I normally use for my printer, and so far that is holding up.

I have a 21-inch iMac with OS 10.7.5.

 

[Slydude]

Thanks for posting back with more info. I personally try to avoid bus powered drives whenever possible. If there is anything at all wrong with the port a drive may not get enough power even if the port can power low drain devices like printers.