Backing up multiple disks to ext. drive while remaining boot functionality - possible?

Use Disk Utility to Erase with Security > Zero option (one slider to the right) to map off bad sectors in advance on any new drives once before cloning.

Use self powered, not port powered drives for backups and clones.

Use Carbon Copy Cloner instead as that also copies the Recovery HD partition and tends to be better suited to making bootable clones work better than others.

https://discussions.apple.com/community/notebooks/macbook_pro?view=documents

verv.paulus wrote:

With all due respect, but have you read my questions?

You threw a lot of confusion into your post.

I think your saying you can't boot from your Lacie HD clone with another backup on it.

I assume you partitioned the drive, so reformat it and just do the clone on it and see if it will work to boot from, if SD doesn't work then use CCC and see if that works. If nothing works, then return the drive and get another brand. If your using a enclosure there has been reports of problems with enclosures not booting, so use a regular external drive. (powered)

Once you determined you have a bootable clone, next reformat the drive again, this time with 2 partitions and use the first one as the clone and see if you can option key boot from it or not. (using a wired or built in keyboard)

Then place extra data on the second partition as you see fit (but not for TimeMachine)

It's not a good choice to place to many software backups on one drive as if the drive dies, then so more backups.

BTW, CCC will save the changes between clones states, much like TimeMachine does, so it needs a larger partition unless you specifically change the default settings and maintain a pure clone.

It looks like I cannot create a bootable clone on my Lacie HD and also backup another external harddrive to it.

Why not? What exactly is the problem? What happens (or doesn't happen)? There shouldn't be any reason you can't copy anything you want to your external HD, whether it's bootable or not. Whether it's 1 partition or 2. Are you trying to use Time Machine to back up one external HD to the other? Are all the HD's formatted as Mac OS Extended (Journaled)?

FWIW, I have mulitple external hard drives. Some of them have 2 partitions, with the 1st partition bootable and the 2nd partition for general storage and backup. I use CarbonCopyCloner and have had no problems, ever. I also have a couple of Lacie external hard drives with 1 bootable partition, same uses.

SD is like CCC, it clones a entire partition of data and if it contains OS X it will make the partition bootable.

CCC has extra benefits including also saving the changed states between the clone versions and backing up the Recovery HD partition which is needed on older Mac's with OS X 10.7/10.8 that don't have built in Internet Recovery to download OS X fresh from Apple's servers.

I now see that it's possible with CCC to partition the disk and have one partition function as a bootable clone, while backing up my other external harddrives to that same disk but a different partition.

Apple's Disk Utility is used for formatting and setting up partitions.

You use Disk Utility to Zero Erase the entire drive first (takes 7 hours for 2TB) to map off bad sectors and then Partition tab > format the drive 2 partitons, with a option: GUID and OS X Extended Journaled as the formats for each partition.

If your going to keep the saved states between clones using CCC (default settings), then set the partition #1 much larger than your boot drive so it has room to store the changes. If not, then set CCC preferences to maintain a pure clone (no saved state changes) and then the partition #1 to 500GB to match your boot drive.

You select the first partition to clone your internal boot drive to it and it should boot hopefullly, and then you will have the rest of the drive to store other data.

I don't advise having all your backups on one drive, if it fails then so dies all your backups, however since the extra space is not going to be used, it doesn't hurt to have a extra backup in case the other drive fails.