Time Machine problem

[Nancy]

Hello all,

My past two backups with Time Machine failed.  The error message said something about it being a "read only" disc (I've been using it for Time Machine backups for a few months now, and it's been writing fine until today.)

When I went into System Preferences to try to re-choose my backup disc, it does not show up, all that shows up are two partitions on the main hard drive.

The backup disk is powered, connected, visible on the desktop and I can open it and get into folders on it.  It also still has half it's space available.  It's a Seagate Freeagent 250 gig.

Any idea what happened, and how I can fix it?

[Nancy]

Well, since I posted this yesterday it fixed itself this morning- after booting up, a box appeared asking if I wanted to make the backup disc the backup disc for time machine.  I said yes and it's been fine since.

However, would still love to hear any feedback if anyone has any of what to do if it decides it's "read only" again, and how to make it show up as an option if it should go missing again.

Nancy

[Nancy]

It's started doing it again, and didn't re-set itself, anyone have any ideas?