Bugs in archival software are revealed in archival time frames.
Circa 2011

My Mac Time Machine saga.

In brief:

Failures to restore from backups:

The utility Migration Manager
speaks of backup disks and seems oblivious to partitions thereon or multiple backup sequences on a partition. The Time Machine app produces a directory on the backup disk whose name is “Backups.backupdb”. In my case there were two directories in that directory. I call such directories in Backups.backupdba ‘backup sequence’ here. It chose a backup sequence on the wrong partition and then spent 45 minutes restoring a backup that was three years old. Further it never informed me of the date of the backup that it was restoring. This makes the debug cycle very slow.
The recovery software on the CD that comes with the machine runs without depending on the content of the internal disk.
I presume that this program is designed to recover all internal disk files from the backup including boot blocks and kernels. It was aware that there were partitions and multiple backup sequences. It was properly spooked, however, that the new target machine did not match the kernel file from the backup. The kernel file on the backup was for the wrong CPU.
The Time Machine software proper
The ‘genius’ at the Apple store did something that I did not quite follow. He seemed to attempt restoring from a backup as one would normally use the Time Machine to recover a specific directory. The result was that the a few years files were still missing.

As of now, after a day of discovering and overcoming obstacles, I have brute force copied files from the internal storage of ‘Time Machine’ to my brand new directory. It took some meagre Unix reflexes such as temporarily changing permissions on the new directory and learning the shell command chown. I ignored complaints such as “Library/Widgets: unable to copy extended attributes” and perhaps there will be mysteries in the future but many of my day to day computer functions are accessible again.

I have not tried to copy the Applications folder over; I have few commercial apps aside from what Apple provides with the machine. Xcode is available on the CD that comes with the machine. Software Update was not much distressed with what it saw.

I spent much of the next day retrieving and setting mail passwords to reenable sending and receiving mail from my several mail accounts. This had nothing to do with Apple software. I plan to experiment with Apple’s Mail application in order to import the mail that I once sent. The Mail app volunteers to import from an ‘mbox’ format. Perhaps I will write a program to convert the old mail in the backup, whose format seems clear, to the mbox format and then import that.

Good news: Mounting the backup disk I found a file called:

It seems to be in ‘mbox’ format and be eight years of mail that I sent from that mail account. Apple’s Mail app imported it with no complaint. I think my mail problems are solved.

Later I decided that I wanted the mail that I had received as well. In the directory …/Library/Mail there is a entry called INBOX.mbox . I took that to be a file in ‘mbox’ format and asked Apple’s Mail app to import it. In the dialog box ‘Import’ there is a radio button which I left at ‘Apple’ Despite this confusion the app liked what it saw and produced a new mailbox within the Mail app with the old mail. I selected the old mail and moved it between the mailboxes as shown by the app. A few days later I am beginning the think that the problem is solved.

Upon a closer look I noticed that the directory entry INBOX.mbox is in fact a directory with Apple magic inside. It was dumb luck that it worked. This time the software looked at its input and deduced its format. Actually there was some extra hair due to the fact that my Unix user name on the old machine was not the same as on the new machine. I had to resort to some Unix chmod lore to read the files.

Time (Machine) marches on.