It’s normal for Time Machine to freeze while copying a large backup

08 Dec 2012

I’m writing this blog post because I couldn’t find any information online about Time Machine hanging while copying files for a backup.

A bit of background: Last week, I accidentally wiped the first ~1 GB of my boot drive with dd because I assumed /dev/disk1 was the removable drive. Thanks to Time Machine, I didn’t lose more than a few minutes of work.

After everything got restored, however, the first Time Machine backup afterwards took a very long time. It seemed to hang after copying about 15 MB, no matter how many times I restarted it. The solution: Watch your computer until it finishes “Preparing Backup,” then let Time Machine run overnight.

If you cancelled the first backup and Time Machine wants to copy your entire hard drive, you need to tell it to inherit the backups from your previous OS X install.

Here’s the log file in case anyone’s interested. I have no idea why it separates the copying into many operations.

12/3/12 11:20:02.699 PM com.apple.backupd[14524]: Starting manual backup
12/3/12 11:20:03.561 PM com.apple.backupd[14524]: Backing up to: /Volumes/Kevin’s WD Time Machine/Backups.backupdb
12/3/12 11:20:04.637 PM com.apple.backupd[14524]: Inheritance scan required for /, associated with previous UUID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXE33CB4
12/3/12 11:20:04.851 PM com.apple.backupd[14524]: Event store UUIDs don't match for volume: Macintosh HD
12/3/12 11:20:06.982 PM com.apple.backupd[14524]: Deep event scan at path:/ reason:must scan subdirs|new event db|
12/3/12 11:20:06.983 PM com.apple.backupd[14524]: First backup after disk inheritance for / - complete scan required
12/4/12 12:03:26.066 AM com.apple.backupd[14524]: Finished scan
12/4/12 12:07:11.597 AM com.apple.backupd[14524]: Found 62118 files (7.34 GB) needing backup
12/4/12 12:07:12.944 AM com.apple.backupd[14524]: 14.73 GB required (including padding), 572.52 GB available
12/4/12 12:20:05.637 AM com.apple.backupd[14524]: Copied 15.1 MB of 7.34 GB, 91406 of 91406 items
12/4/12 1:20:06.371 AM com.apple.backupd[14524]: Copied 15.2 MB of 7.34 GB, 636464 of 636464 items
12/4/12 2:20:06.602 AM com.apple.backupd[14524]: Copied 61 MB of 7.34 GB, 968341 of 968341 items
12/4/12 3:20:07.020 AM com.apple.backupd[14524]: Copied 61 MB of 7.34 GB, 1128509 of 1128509 items
12/4/12 4:20:07.373 AM com.apple.backupd[14524]: Copied 7.01 GB of 7.34 GB, 1749413 of 1749413 items
12/4/12 4:42:53.173 AM com.apple.backupd[14524]: Copied 2041957 files (7.34 GB) from volume Macintosh HD.
12/4/12 4:42:57.259 AM com.apple.backupd[14524]: Using file event preflight for Macintosh HD
12/4/12 4:43:00.507 AM com.apple.backupd[14524]: Will copy (1.5 MB) from Macintosh HD
12/4/12 4:43:00.527 AM com.apple.backupd[14524]: Found 187 files (1.5 MB) needing backup
12/4/12 4:43:00.574 AM com.apple.backupd[14524]: 6.43 GB required (including padding), 563.23 GB available
12/4/12 4:43:55.494 AM com.apple.backupd[14524]: Copied 4614 files (1.6 MB) from volume Macintosh HD.
12/4/12 4:43:58.155 AM com.apple.backupd[14524]: Created new backup: 2012-12-04-044355