Time Machine Backup Corrupted. How to Repair?

[noobforlife]

Anyone know what to do about a bad catalog b-tree in a sparsebundle? My hard drive crashed. I turned to Time Machine to restore it. I found its sparsebundle was corrupted, too.

Here is what I have tried:

Repairing from Disk Utility:
No luck. "Disk Utility can't repair this disk. Back up as many of your files as possible . . ."
Console reported:
Feb 7 10:00:01 tmps-MacBook-Pro diskarbitrationd12: unable to repair /dev/disk3s2 (status code 0x00000008).
Feb 7 10:00:02 tmps-MacBook-Pro diskmanagementd3115: APICALLBACK_dmAsyncFinishedForDisk_FSCK_result dmErr=-9957 detailErr=8

Repairing from Disk Warrior:
Again, no luck: The directory of the disk "Time Machine Backups" cannot be rebuilt. This disk is not eligible. Only Mac OS disks that are locally attached are eligible.
Console reported:
2/7/10 10:06:38 AM DiskWarrior App: Error resolving disk with VM pages. (-43)
2/7/10 10:08:48 AM hdiutil: detach: timeout for DiskArbitration expired
2/7/10 10:08:48 AM hdiutil: detach: drive not detached
2/7/10 10:08:48 AM DiskWarriorRebuildServer: Error 1 executing '/usr/bin/hdiutil'
2/7/10 10:08:48 AM DiskWarrior App: hdiutil detach returned 2
2/7/10 10:08:59 AM DiskWarrior App: Error resolving disk with VM pages. (-43)

Lastly, I tried the method on this web page (even though the problem they described wasn't mine):

http://blog.jthon.com/?p=31

It involves attaching the sparsebundle drive without mounting it and running fsck against it.

Still no luck.

Executing fsck_hfs (version diskdev_cmds-491~1).
Checking Journaled HFS Plus volume.
Detected a case-sensitive volume.
Checking extents overflow file.
Checking catalog file.
Rebuilding catalog B-tree.
Invalid node structure
(14, 50220)
Invalid record count
(14, 50220)
The volume Time Machine Backups could not be repaired.

The b-tree looks bad and I have no idea what do do about it now.

Thanks much!

 

[grahamperrin]

Sparse bundle disk images, HFS Plus repairs, Time Machine, restoration, reliability

… bad catalog b-tree …

JanX2 wrote:

Just a FYI: I have been using this to repair broken Time Machine sparseimage backups for a while now. It takes ages (on the order of days), but it has not failed me yet:

fsck_hfs -c 2G -dfy -Race /dev/rdiskXsY​

Check this for details: http://blog.jthon.com/?p=31

How to fix a Corrupted Time Machine Backup | Jthon's Place (2008-07-20)

Also with reference to that 2008 post, in Ask Different:

How can I avoid repeated “Time Machine must create a new backup” errors when backing up to a third party NAS?

From Suitability of HFS Plus (my answer):

Degrees of failure

In the past I sometimes forced fsck_hfs(8) to rebuild b-tree files … with limited success but not certainty. Whilst a file system may appear to be OK (in Disk Utility and the like) I would no longer trust it for Time Machine backup or restoration purposes.

In the most recent case (above) multiple applications of force (multiple rebuilds of the catalog b-tree, a rebuild of the extended attributes b-tree and a rebuild of the extents b-tree) have not led to a verifiable file system. I have debug logs from these attempts, which I'll not begin to summarise here; they're massive. …​