Time Machine: "Partially Deleted Backup"

Pondini wrote:
Your backups are corrupted.

Try a +*Repair Disk+* (not permissions) via Disk Utility. It might be able to delete it; you may have to run it a couple of times.

If not, and you already have +Disk Warrior+ or another 3rd-party heavy-duty disk repair app, it might be able to fix it, but be certain whatever you use is compatible with Leopard. If it's +Disk Warrior,+ be sure it's 4.1.1 or 4.2 (free upgrade from earlier versions).

Unless you think you'll need it in the future, though, I wouldn't spend the $100 or so for DW (or somewhat less for the others).

Otherwise, your best bet may be to reformat your TM drive and let it start fresh.

Pondini wrote:

Maxwell’s Demon wrote:
. . .
Really? What about the symptom leaves no doubt?

It's not the symptoms. It's the multi-link structure. For more details: http://www.appleinsider.com/articles/07/10/12/roadto_mac_os_x_leopard_timemachine.html
and: http://arstechnica.com/apple/reviews/2007/10/mac-os-x-10-5.ars/14

I'm aware of the multilink nature of TM's backups. What I don't understand is how you immediately concluded that the backups were corrupted.
In my initial post I indicated that I was thinking about going into TM and deleting the partially deleted backup that was causing TM to stall. I get the impression that had I done so, the "corruption" you spoke of may still have remained. So, that's why I asked how you immediately concluded that there was corruption, rather than just a partial file remaining that was causing TM to stumble. (After all, when I finally did tell TM to stop backing up as it was continuing to stall, after it stopped it reported (in the system log) that the actual backup it was finishing up when it began to stumble was successful.)

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You're not going to be able to restore from the backup folders you moved back.

Huh? I didn't move anything "back."

What TM will do with them when they "expire" is anybody's guess; TM may do further backups, and if you force a "deep traversal," it may back-up anything that has lost it's link(s).

You've lost me.

(Funny...for some reason, I had the feeling that such utilities were not meant to be used on Time Machine drives.)

DW 4.1.1 (or 4.2) can, and probably the others, if they say they're compatible with Leopard and don't exclude Time Machine. DW can often fix backups that DU can't.

It took forever. I ran TechTool Pro, and it "choked" (i.e., ran out of memory) trying to rebuild the directory. When I asked Disk Warrior to graph the directory, it revealed that it was more than 40% fragmented!
So I ran Disk Warrior. It ran without incident. When I then looked inside the TM drive, I discovered that along with rebuilding the directory—which is what I understood its job to be—DW apparently removed/deleted the offending (partially deleted) backup. The next time Time Machine ran, everything went smoothly. It's been running fine ever since.
I'm obviously quite pleased with the results: Not only did DW perform an incredible directory rebuild (fragmentation went from more than 40% to less than 1% !!) but it cleared out the partially deleted backup that was causing TM to stumble. But I remain awfully curious: Had I simply gone into Time Machine and deleted the partially deleted backup myself, wouldn't that have fixed the problem? (Granted, DW not only got TM back on track, but it also rebuilt its directory, which is a definite plus in my mind...I'm just trying to understand.)

Pondini wrote:

Maxwell’s Demon wrote:
. . .
I'm aware of the multilink nature of TM's backups. What I don't understand is how you immediately concluded that the backups were corrupted.

TM finding partially deleted backups, trying repeatedly to deleted them, and failing to.
(And yes, I though you meant that you'd tried to delete the backup yourself.)

It took forever. I ran TechTool Pro, and it "choked" (i.e., ran out of memory) trying to rebuild the directory. When I asked Disk Warrior to graph the directory, it revealed that it was more than 40% fragmented!

I'm not sure fragmentation is a problem, or even applies, given the structure of TM backups.

So I ran Disk Warrior. It ran without incident. When I then looked inside the TM drive, I discovered that along with rebuilding the directory—which is what I understood its job to be—DW apparently removed/deleted the offending (partially deleted) backup. The next time Time Machine ran, everything went smoothly. It's been running fine ever since.

Great! And yes, there are times it can repair/rebuild TM backups that nothing else can (I guess that's why it costs $100!).

I'm obviously quite pleased with the results: Not only did DW perform an incredible directory rebuild (fragmentation went from more than 40% to less than 1% !!) but it cleared out the partially deleted backup that was causing TM to stumble. But I remain awfully curious: Had I simply gone into Time Machine and deleted the partially deleted backup myself, wouldn't that have fixed the problem? (Granted, DW not only got TM back on track, but it also rebuilt its directory, which is a definite plus in my mind...I'm just trying to understand.)

It's possible you couldn't have deleted it completely, any more than TM was able to. Remember, a single backup folder has hard links to hundreds, thousands, or hundreds of thousands of other items. Just one of those being screwy can have a ripple effect through the whole structure.

And if you could have, it might well have left some of the actual backup files "abandoned" -- some or all of the hard links to them deleted, but still somewhere in the disk directory, so still taking up space.

I got the idea from
http://www.macosxhints.com/article.php?story=20090515063602219
which provided a link to the "solution" when partial backups remain that result in TM "error: 11" failures:
http://www.bytebot.net/blog/archives/2008/08/13/fixing-time-machine-backup-faile d-with-error-11
Admittedly, mine wasn't an "error: 11" problem, but it sure seemed similar. My hesitation/concern was due to the fact that the partially deleted backup was the last one (i.e., the "oldest") in my TM volume: I wasn't sure if deleting it would screw up all of the links used by the remaining backups. However, since DW removed it without causing any problems, it seems like I may have been able to accomplish the same result by removing it "manually" from within TM. If that is the case, then it suggests that there may not have been any actual "corruption."
Again, I am very happy with the result, and likely will resort to DW again the next time I have similar problems. The only reason I'm harping on it is simply to try to gain a deeper understanding of how to determine when such problems are indeed due to corruption as opposed to simply an errant file that causes TM to stumble. (Had TM indicated that it stumbled and was unable to successfully perform the backup, then I would have little doubt that there was actual corruption.)

Pondini wrote:

Admittedly, mine wasn't an "error: 11" problem, but it sure seemed similar.

No. They're talking about deleting the "in.Progress" package, which is the remains of a cancelled or failed backup, and always the +most recent+ one listed. There's no reason to delete it manually, as is designed to recover all by itself.

And those "solutions" don't really apply, either. Error 11 usually occurs with one of the messages listed in #C3 of the Time Machine - Troubleshooting *User Tip* at the top of this forum.

That Tip is also the place to start if you ever have other troubles with TM. It's not been officially "blessed" by Apple, of course, but some of the TM engineers have seen it, and the advice was gathered from many solutions posted here by several of the TM "gurus" that lurk in the TM forums.

Well, I guess it will always nag me (i.e., whether or not going into TM to delete such a file that needs to be deleted anyway would work, not work, or make things worse). But, I'll get over it. 😉
Thanks for all of your help, James.