Time Machine Won't Backup

[BeowolfS]

I have been trying to back up my iMac 21.5inch - Mid 2011 (running Lion 10.7.5) using Time Machine. The backup target disk is a Seagate "Backup Plus For Mac" 500GB external drive, connected with a USB 3.0 cable.

Every time I have tried to back up, Time Machine will run for a few minutes and stop with a message that the "disk has been improperly disconnected". Then my iMac freezes and I have to do a hard reboot.

The disk was not disconnected at any time during the backup. The Seagate disk checks out as fine. I have tried reformatting the disk with not results.

Any suggestions as to what might be going wrong?

 

[Slydude]

I did a little digging about this with the help of the great Google monster and have not found anything specific yet. I did find out that some models of this drive ship with a piece of Paragon software to make it useful for Mac and PC. That is making me wonder how your drive is formatted. Here is what I would try:

With the drive connected and mounted in the Finder press Command I to bring up the Get Info window. If the drive will be used with Time Machine it must be formatted HFS+ extended, journaled. If the drive needs to be formatted you can do that from Disk Utility.

BTW is this drive powered from the USB port or does it have a separate power cord. The error you are getting sounds suspiciously like the drive is formatted correctly but not getting enough power. This sometimes happens with US bus-powered drives that must be connected to two ports.

 

[chscag]

The backup target disk is a Seagate "Backup Plus For Mac" 500GB external drive, connected with a USB 3.0 cable.

Just a thought here..... since your 21.5" 2011 iMac does not support USB 3.0 drives as USB 3.0, that may be the problem. I know that USB 3.0 drives are supposed to be backward compatible with USB 2.0. Sometimes, they're not. I'm basing that on personal experience. I have the same exact machine you have and had to return a USB 3.0 drive to Best Buy because it did not work right with my iMac.

 

[BeowolfS]

thank you

Thanks for the assistance, Slydude and chscag!

This drive is powered by the USB connector. Since I have already reformatted the drive as indicated, the power cord may be the issue.

I don't think I will be able to return it to Best Buy, so I guess I just have another external drive for movie and music.

Is there another drive that either of you would recommend?