Time Capsule Hanging on "Preparing backup"

Question

OK, I read some of the previous discussions here but I want to throw this out there, as my setup mightbe a bit weird.
I have a GLYPH 2TB drive hooked via its USB  cable to an Airport Express. (The model I bought in 2012 or so)
The drive shows up fine via the wireless connection and in the past Time Machine seems to have done backups OK. It was slow, but I was only doing it once a month or so.
So, what happens. I decide to run a copy of TechTool on my computer after it crashes and won't start up (I got the status bar under the apple logo on startup, while the screen was still gray). I start it from an external drive I have it saved on. A little LaCie number. The computer runs OK when I do that.
So I run TechTool. It tells me I have bad blocks all over. I tried Restore and Disk Repair and I get told that my Apple MacBook can't alter any information on the drive, though it can be read. OK I thought, I need to do a wipe. My last backup was in July.
So I fire up Time Machine. It finds the big drive fine. Then it takes a long time to prepare, and then it started backing up. It only did about 13 MB and then hung for a long time, like an hour.
So I stop Backup, and restart, and try again. This time it hangs on "Preparing." For another hour or so. I do a stop backup, restart, and the same thing. Hmm. I look on the discussion boards here and find Pndini's site with suggestions. I turn off On-Access Scanning in Sophos.
So. It's been an hour and it still hangs but I might just wait to see what happens. I read that there's a spotlight file I might need to change, but I wanted to make sure I knew what I was doing.
Q: can I stop the backup, and just disconnect the drive from the Airport and link it via USB and try that? I wasn't sure if that was a safe thing to do. If I can't and I need to just wipe this thing that's OK, the stuff from July is enough as I moved the files I was concerned about to the LaCie drive with the finder (I just put them all in a folder) and I can always pull them back up. Plainly my MacBook hard drive is going to die soon but I need a computer for the next couple of weeks to work from.
So, what should be my first step? Like I said, if necessary I can nuke the MacBook's drive as long as I can restore from my july TM backup.

Answer 1

9rabbit wrote:
THe system I started up from was a little drive I backed up a copy of the system on . . .
When you did that, you copied Time Machine's instructions, along with everything else.
Those instructions are kept in a file on the internal HD, along with all sorts of other preferences and setup information -- pretty much anything in System Preferences or your settings and preferences for applications is stored that way, and was copied to the clone.  That's kinda the purpose of a clone.
Anyhow, understand, when it looked like my HD was failing, I ran the system from there so I could at least access some files if need be. I ran Time Machine's backup from the top of the menu nbar just like always,
Time Machine used the copied instructions, unless you specifically changed them on the clone.  That means it was still (trying to) back up the internal HD, not the clone. 
I did look BTW in the Restore OS 10.8 drive and go through the steps, after connecting via the network it shows the older backups.
You may not have noticed, but that almost certainly names the internal HD near the top of this window, after "Restore from":
I should be able to disconnect the glyoh from the airport, plug it into the mac, run TM and it will back up stuff to there. 
Unless you change the exclusions, it will continue to (try to) back up the internal (not the external) to the Glyph.  But you may have difficulty seeing those backups, because of the change from network to local as in the blue box of the link above.
if I can just wipe the internal drive, I can restore the copy of the system (10.8.3) and then do a TM restore
No need to reinstall OSX, if the backups are intact (by no means a sure thing).  The restore erases the destination, then restores OSX and everything else from the backups.
But since both your internal HD and backups are suspect, I'd strongly recommend getting another external and restoring to it first, before wiping the internal.  Then see if you can start up from it, and if it runs properly.
If it doesn't, we've got another option, but it's also best to do on another drive first.