Time Machine Backs Up Entire External Drive Each Backup

This will be a lengthy post, I'll do my best to shorten it as much as possible, but I apologize if its a quite a read.

Here's some information about my setup. I have an iMac (500 gigs) with a 500 gigabyte Glyph drive that I use to store my Pro Tools sessions. I have a 2 terabyte time machine set up to backup BOTH my iMac's internal hard drive and my Glyph Drive.

Side Note: The Glyph drive is kind of a fancy drive with an on/off switch.. turning it off basically is the same as ejecting (obviously you have to eject it, then turn it off).

For about 2 years, my time machine was setup to auto backup, the standard time, every hour. Now, there were days when my Glyph drive was on when the time machine would include my Glyph drive along with the iMac backups... and there were other days when the Glyph drive was off and the time machine would just back up the iMac. For 2 years, time machine functioned just fine with ignoring my glyph drive when it was off and when it was on, picking up where it last left off and updating the new changes from the Glyph.

Well, recently, as 2-3 months ago, I wanted to clean my Glyph drive, I was getting some errors from Pro Tools about fragmentation on the Glyph that I ignored for a very long time. I decided to finally do it. I dragged all of my sessions off my Glyph drive and onto another external drive, then I wiped the Glyph and put back all of the sessions. I knew that when I did this, Time Machine was not going to recognize the Glyph drive anymore and re-backup the whole thing and that's exactly what it did. I plugged it in after the I put all the files on it and time machine backed it up as a new drive (118 gigs of stuff). I figured what I would do is delete all the old Glyph drive backups (prior to the Glyph wipe), since they were duplicate backups that were eating up twice the space, if not more. So, I went back and found the old Glyph drive backups and said chose the option to delete all backups of that file. Now, my Time Machine had all my iMac backups for the past 2 years and a fresh new backup of my Glyph.

Here's where the problems started. If I left the Glyph drive plugged it during every backup, Time Machine was fine and only backed up what had changed on the Glyph drive... If I turned off the Glyph drive (ejected it) and Time Machine made just one backup without the Glyph on, the next time the Glyph would be on, Time Machine would re-backup the whole drive (118 gigs). So, time machine recognizes the drive as long as the last backup had both iMac+Glyph.. if there's a backup with just iMac, the next backup of the iMac+Glyph would re-backup the whole Glyph drive, like its forgetting that it was the same drive plugged in last time. I know something is screwy because it never used to 'forget' the drive... it used to always just pick back up where it left off whenever the drive was available again.

I don't know how accurate Pondini is, but here's a quote I found from the site:

http://pondini.org/TM/32.html

If a drive isn't available (such as an external that isn't always connected), Time Machine will just skip it, and continue backing-up all others normally. The next time it's available, Time Machine will back up whatever's new or changed since the last backup of that volume. If it's been disconnected for a long time, the next backup may be longer than usual.

Anyways, the last 2-3 months, my workaround has been this. I turned off automatic syncs, because every hour that my time machine synced without the glyph, the next time the glyph was available, it would rebackup the whole thing. So I turned off automatic syncs and switched to manual syncs. I only sync once a day now and thats after working on a Pro Tools session when the drive is on. I'll sync it once, then turn the drive off... this way every single backup has a glyph drive in it.

Today, something odd happened. For some reason, time machine skipped my glyph drive during a backup... I looked in the backup folder that should normally be both iMac and Glyph and just iMac was there. I went to backup again and now it started to sync my whole Glyph again. So I cancelled the backup.. I went back and deleted the last backup before (the just iMac one) and then tried another backup and it worked just fine. As soon as I removed the backup that was missing the Glyph, it picked back up from last time.

Anyway, this is absolutely crazy. I've been dealing with it ever since I cleaned my Glyph drive.. I'm really hoping for a solution that doesn't involve reformatting again or losing my backups. That'll scare the heck out of me, but I'll try whatever anyone suggests.

This is a great community and I'm extremely appreciative of the help you guys have given me in the past. Thanks for your time, if you've made it this far.

As a note, I also properly eject my Glyph drive with the eject button under devices before turning off.