Backup without erasing?

[jefferis]

I have a backup firewire disk that has 2 disks backed up on it [boot and another], but just got SuperDuper. I'd like to clone my boot disk without erasing the extra files on the backup. It SEEMS that all the SD options say they will erase the files on the backup not on the original.

What is the best way to backup the drive or at least user directory, without wiping out the other data?

Thanks

Jeff

[dnanian]

Well, the best thing to do is repartition to have a place to put the backups in isolation. You can partition "live" with iPartition from Coriolis Systems.

But, there are alternatives. To just copy to the source, without erasing anything, you can use either "Copy Newer" or "Copy Different", neither of which will erase files (though some might be overwritten). Note, though, that this type of backup is NOT guaranteed to be bootable, since OS files might need to be erased to ensure this will work.

Alternatively, you can back up to a sparse image as described in http://www.shirt-pocket.com/forums/showthread.php?t=81. That can stay side by side. While an image can't be booted from directly, if updated with Smart Update it'll retain its bootability on restore.

[jefferis]

I take it that with either of these Copy methods, you won't be able to have a Safe User backup then, for keeping a live backup of the current boot user?

[dnanian]

I'm not sure what a "Safe User" back up is...

[jefferis]

I found that if you select Safety clone users and applications and choose Copy only New files, it copies without erasing the existing files AND creates the clone of the User folder for safe backups. I wanted to use the active user backup files as promised in the materials as well as back up without erasing the target disk. This procedure may be just what i needed.

[dnanian]

I don't think so, actually.

For one thing, the Safety Clone does not copy your user files. It links to them, on the original volume. As such, it's not a backup at all -- it's more of a checkpoint of your system.

On top of that, you can only do the "Copy Newer" one time. Future attempts to update the Safety Clone will not guarantee bootability, or even a very valid system, because things won't be copied properly...

I really don't think you should be doing this... you should partition if you're going to attempt more advanced things like the Safety Clone.