View Full Version : Strategy for backing up two internal drives to one external drive?
03-19-2005, 11:33 AM
I'm evaluating Super Duper! I've read the manual but just wanted to check whether Super Duper! can deal with the following situation?
I have two internal hard drives that I want to back up. One is called 'Macintosh HD' and this has my system on it, as well as my applications and my user folder. The second internal drive is called Hard Drive 2 and has my photos and music on it.
I want to back both of these drives up to an external Firewire drive called 'Backup' and, ideally, that would then be bootable. From reading the manual, I *think* I would be able to create an initial backup of 'Macintosh HD' using Erase then Copy. Subsequent backups of 'Macintosh HD' would use Copy Newer/Different.
My intial backup of 'Hard Drive 2' would use Copy Newer/Different right from the start to avoid erasing any of the backed up files from 'Macintosh HD'.
1. Will this strategy work?
2. Would the folders/files from Hard Drive 2 simply be placed at the root of 'Backup'? If so, this is fine...
3. What if the occasional file on 'Hard Drive 2' happened to have the same name as one of the ones on 'Macintosh HD', even though they were completely unconnected. Does Super Duper! understand that they are from completely different sources when writing to the Backup?
4. I'd rather not use Cron, so will I be able to use the built in Daily backup script to achieve all this? i realise that scheduling is going to get alot better in v2.0...
03-19-2005, 12:00 PM
In general, this technique will not work. Updated to OSX will often make significant modifications to the location and number of files in the system folders. If you don't let SuperDuper! remove/move files (a "move" would be a copy of the new file and a delete of the old one), then you can end up with a reasonable backup that is no longer bootable due to OS and other changes.
The best thing to do is to partition the Backup drive into two volumes, one for each drive. That will allow you to use Smart Update as intended, and will ensure the bootability of the main volume. This will resolve each problem you list in the best possible way... and there's no real disadvantage, either.
Regarding scheduling/Daily Backup, since you've got two sources and two destinations, you'd want to create two scripts. You can copy the Daily Backup *application* (not the script), and then open it in Script Editor. The first one would be "Daily Backup" and the 2nd would be some other name, like "Daily Backup 2". Edit the script by dragging and dropping the application onto Script Editor and change the line that reads:
run using settings "Daily Backup" without user interaction
to use a different settings file, such as "Daily Backup 2", like so:
run using settings "Daily Backup 2" without user interaction
Save the script application.
OK. Then you'd follow the instructions in Section 12 of the User's Guide to save the settings for the two backup operations, one in "Daily Backup" and one in "Daily Backup 2". Then, you can use those two little applications to schedule.
You don't have to use Cron: instead, use iCal. To do so, create a new calendar just to keep things clear, and create two events, one for each script, at a time of your choosing.
Then, set the alarm for 0 minutes before, and tell it to open a file as the alarm action -- use "Daily Backup" for one and "Daily Backup 2" for the other. That's all there is to it!
03-20-2005, 05:31 PM
Thanks for your guidance. I've registered now and have partitioned my backup drive as you advised. I've also successfully made a backup of my boot volume and have tested it - it works fine.
However, I left it backing up my second hard drive last night. This didn't complete; it simply said it had encountered an error. Although Super Duper didn't mention it, the problem is probably that my startup volume has gone from having about 20GB of free space (out of 60GB) to having only 300MB spare overnight. I think there's a good chance this is connected with the backup process because, apart from iTunes, that was then only application I was using.
I've used the Finder's Find function to try and locate either recently created large files (> 3GB) or many small files (anything created within the last day) but have found nothing that explains the difference.
I could use my backup to revert my startup volume, but before I do that, I wanted to try and find the source of the problem. Have you have seen anything like this before that could be down to Super Duper?
Ideally, I would also like to compare the backup and start up volumes and get a list of files that appear on one but not the other. Do you know of any tool that will do this?
03-20-2005, 06:07 PM
That sounds like your network failed during backup, which caused the target volume to vanish. SD! wasn't told by the system it happened, so it kept backing up to the directory it was backing up to... which was then local. ("Mount points" in OSX look just like folders to SD!.)
So, I think if you look in /Volumes (use "Go to folder"), it's likely you'll find a folder there named the same as your backup target, with files in it. (Make sure you don't have the backup volume attached when you check this.) If so, remove the folder and empty your trash -- that's where the space is.
The only way to "fix" this is to improve the reliability of your source or destination networking... (and for OSX to fix the problem where it drops a volume but doesn't tell us it happened with an error...)
03-20-2005, 07:51 PM
You're spot on - that's exactly what happened. My external drive (Maxtor One Touch 250GB) does 'dismount' with alarming frequency and the folders were there.
Thanks very much for your quick and accurate responses!
03-21-2005, 09:00 AM
No problem. (Sorry for the "network" bit -- earlier you had indicated that you were going across a network, so I thought that perhaps it was still going that way. In any case, the main thrust of the response should be accurate!)
Do you have your FireWire drive chained with an iSight, or other FW peripherals that might be interfering with the bus? If not, check the Maxtor site for a firmware update that might increase its reliability... or, swap cables. Voodoo, I know...!
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