How to copy Time Machine Backups to another External HD

opentrail wrote:
I have the same error message reported. Very annoying. I can actually engage TM on my old drive, but when I tried to copy the old stuff to the new drive I get the same message "The operation can't be completed because it isn't supported" even with ignore ownership unchecked. Look like a big Apple bug to me and incorrect instructions on thread http://support.apple.com/kb/ht1427

How are you copying (drag via the Finder or Restore via Disk Utility)?

And are you copying a sparse bundle or a Backups.backupdb folder?

If you're copying a Backups.backupdb folder, the new drive must have either the GUID or APM *Partition Map Scheme,* and if the source volume is case-sensitive, the destination volume must be, too.

Have you Repaired the backups you're copying from?

I can't use the Restore from the disk utility because although I'm using 2 1Tb drives, my destination is some 4k smaller than the source and the restore utility complains about this even thought the source drive is not completely full.

So I have used the Finder to copy the Backups.backupdb folder to the destination drive and that is when I get the error message.

Both drives are formatted exactly the same with a GUID partition table - I'm using an Intel machine.

Disk Utility refuses to repair the source disk and in the warning message tells me to copy the contents which is exactly what I am trying to do. I can actually mount the source drive and run Time Machine and successfully browse past backups.

So in my opinion I have found a major Apple bug which kinda defeats the purpose of TimeMachine.

The workaround is to start a new backup on the target disk and keep the source disk in safe keeping if I ever need it again... not what I want, but I don't see any other choice.... "It Just Doesn't work"

opentrail wrote:
I can't use the Restore from the disk utility because although I'm using 2 1Tb drives, my destination is some 4k smaller than the source and the restore utility complains about this even thought the source drive is not completely full.

So I have used the Finder to copy the Backups.backupdb folder to the destination drive and that is when I get the error message.

If neither Disk Utility nor Disk Warrior can repair your backups, they're hopelessly corrupted.

If your backups are corrupted, you cannot copy them, either with Disk Utility or the Finder.

The message you got, about copying off what you can, is a generic one, and a bit misleading in this case. If you had +*other data+* that was not corrupted on that disk, you could copy that data.

But Time Machine backups are so completely interconnected with multiple hard links (sort of like aliases), at both the file and directory level, that if there's corruption, reliable copying isn't possible.

Thanks for the explanation - much appreciated.

I will keep the old drive as it still does have a lot of information in the event I have to recover some of the files.

In the meantime... I've started with a fresh Backup on a new disk.

I guess what I need to prevent these kinda things happening is a Backup RAID rack.... assuming that the corruption is caused by the drive and not from the act of backing up from Mac OS.

opentrail wrote:
. . .
I guess what I need to prevent these kinda things happening is a Backup RAID rack.... assuming that the corruption is caused by the drive and not from the act of backing up from Mac OS.

It's hard to tell what causes this sort of thing.

It can be some sort of glitch during the backup, possibly even a corrupted file on your HD; your TM drive beginning to fail; or some sort of problem with the Time Machine backup process.

I've learned over the years (mostly the hard way, of course 😟 ), never to trust my backups to a single app or piece of hardware: no app is perfect, and all hardware fails, sooner or later.

Like many here, I keep both full Time Machine backups, plus a "bootable clone" on a separate external HD. I use CarbonCopyCloner, many use the similar SuperDuper. That gives me the best of both types of backups, plus of course a completely separate, independent backup.

CCC is donationware; SD has a free version, but you need the paid one (about $30) to do updates instead of full replacements, or scheduling. Either is easily found via Google.

And/or, see Kappy's post on Basic Backup, complete with links to the web sites of each product.

Thanks for the advice. I too actually use SuperDuper to make an image of my hard disk and have being using TM for those historic incremental backups. Recommend SuperDuper.