Wondering if my external drive has been backed up on Drobo or not

Question

I apologize in advance for my long question that may sound confusing and/or repetitive.
I have been backing up my Mac and external firewire 800 drive to my Drobo using Time Machine for a year now. Recently my Drobo started having problems, cannot mount on the desktop. I have been dealing for over a month now with Drobo tech. support trying to fix the issue, had 2 failed attemps of repair via Disc utility and for all this time I haven't been backing up. (for 1.5 months).
Finally today I tried Diskwarrior on Drobo to save the data on it. I could only see the previews of my backups though the external hard drive seems to have been backed up only 3 times (at the beginning) and never since (for 10 months). I haven't changed anything in my set up since I started Time Machine. So I am wondering why I cannot see the external hard drive's backups? Could it be because the data is corrupted or because Time Machine never backed it up after the first 3 days?
I also tried Data Rescue Beta today to run a quick scan on the Drobo and had the same result. I asked their support service the same question and waiting for their answer now.
I am asking this because since yesterday my external drive that contains really important data cannot mount on the desktop. So I may loose very important data I haven't backed up neither archived.
Thank you very much for taking the time to read this. I hope to hear some suggestions.

Answer 1

irem-888 wrote:
So I am wondering why I cannot see the external hard drive's backups? Could it be because the data is corrupted
Probably. Time Machine backups have a very complex structure, and are all interlinked. So when something gets corrupted, there's no telling what was there before things went awry.
or because Time Machine never backed it up after the first 3 days?
Anything's possible, but that's doubtful. If the drive was connected, and not specifically excluded, it would have been backed-up. If there was a problem backing-it up, the backup would have failed with a (more or less) descriptive message.
If Time Machine was still able to do backups in the last week or so, you might be able to find the messages it sent to your logs, including how much was backed-up from each volume. See #A1 in Time Machine - Troubleshooting (or use the link in *User Tips* at the top of this forum). Most likely, you'll need the instructions in the pink box to use Console to see the previous logs.
I am asking this because since yesterday my external drive that contains really important data cannot mount on the desktop.
If Disk Utility can see it, try a +*repair disk+* (not permissions). See #A5 in Troubleshooting if you need instructions. If that (or Disk Warrior) can fix it, obviously, back it up immediately, via the Restore tab of Disk Utility, or a 3rd-party app such as CarbonCopyCloner or the similar SuperDuper (either easily found via Google).
If not, you'll need specialized +Data Recovery+ software, or a service that performs the function. It's not cheap, and there are no guarantees.
The app mentioned here most often is Data Rescue 3, and it seems to get good reviews, but I haven't used it myself, so can't recommend it over any of the others.
Another is File Salvage.
Some of these have a free "trial mode," that will tell you if there's anything to be recovered, and perhaps recover a single file. For more, you have to pay the $$.
You'll also need another drive to receive anything it can recover.
Look for apps or services under +Data Recovery+ via Google, VersionTracker.com, or MacUpdate.com.
But don't expect to get a nice list of folders and files, organized in any recognizable way. It will be a random list of files. You may get the original file names, in some cases, or there may be some assigned names (if the actual name couldn't be determined).
Because of that, if you need to do recovery, do it from the external, not the Time Machine backups; sorting out what was found won't be easy either way, but practically impossible on the backups, since there are probably several hundred thousand, or more, files on it.