Time Machine hasn't done a successful backup since yesterday afternoon. When I click on the Time Machine icon in the menu I will sometimes see it backing up. I just tried "Back Up Now"; it made it to "Backing up 26.8MB of 30.4MB", then it stopped.
I tried turning backups off and on yesterday after I noticed that they weren't happening, but that didn't help. I just rebooted to see if that will help, I'll update here if it does.
Here are the console messages for Any = backupd
default 11:34:35.832712 -0400 backupd Received claim B5C77086-901F-4907-B85C-3F89880B9450
default 11:34:35.832792 -0400 backupd Claim B5C77086-901F-4907-B85C-3F89880B9450 granted in server
default 11:34:35.832830 -0400 backupd Claim B5C77086-901F-4907-B85C-3F89880B9450 invoked in server
default 11:34:35.833665 -0400 backupd Claim B5C77086-901F-4907-B85C-3F89880B9450 was revoked
default 11:39:35.816340 -0400 backupd Received claim 8AF1BE5C-4B94-4CCB-B859-CAD5CB05A8D1
default 11:39:35.816502 -0400 backupd Claim 8AF1BE5C-4B94-4CCB-B859-CAD5CB05A8D1 granted in server
default 11:39:35.816569 -0400 backupd Claim 8AF1BE5C-4B94-4CCB-B859-CAD5CB05A8D1 invoked in server
default 11:39:35.817826 -0400 backupd Claim 8AF1BE5C-4B94-4CCB-B859-CAD5CB05A8D1 was revoked
error 11:39:50.669080 -0400 backupd Failed to remove attribute 'com.apple.backupd.SnapshotVolumeFSEventStoreUUID' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
error 11:39:50.674698 -0400 backupd Failed to remove attribute 'com.apple.backupd.SnapshotVolumeLastFSEventID' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
error 11:39:50.674868 -0400 backupd Failed to remove attribute 'com.apple.backupd.SnapshotVolumeUUID' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
error 11:39:50.674973 -0400 backupd Failed to remove attribute 'com.apple.backupd.PreviousSnapshotVolumeUUID' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
error 11:39:50.675078 -0400 backupd Failed to remove attribute 'com.apple.backupd.PreviousSnapshotVolumeName' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
error 11:39:50.675198 -0400 backupd Failed to remove attribute 'com.apple.backupd.VolumeBytesUsed' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
error 11:39:50.675409 -0400 backupd Failed to remove attribute 'com.apple.backupd.VolumeIsCaseSensitive' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
error 11:39:50.675570 -0400 backupd Failed to remove attribute 'com.apple.backupd.fstypename' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
error 11:39:50.675747 -0400 backupd Failed to remove attribute 'com.apple.backupd.VolumeIsEncrypted' from 'file:///', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
default 11:39:50.686644 -0400 backupd Read (Subarbitration) options: 1 -- URL: <private> -- purposeID: com.apple.TimeMachine.snapshot -- claimID: 6B7AE51D-0E64-4E6A-BC6B-44CF709DF46F
default 11:39:50.687699 -0400 backupd Subarbitration claim 6B7AE51D-0E64-4E6A-BC6B-44CF709DF46F granted in client
default 11:39:50.687732 -0400 backupd Subarbitration claim 6B7AE51D-0E64-4E6A-BC6B-44CF709DF46F invoked in client
default 11:39:50.692510 -0400 backupd Read options: 1 -- URL: <private> -- purposeID: com.apple.TimeMachine.snapshot -- claimID: D188EE79-C70B-4646-99A9-0A1E79335461
default 11:39:50.692640 -0400 backupd Received claim D188EE79-C70B-4646-99A9-0A1E79335461
default 11:39:50.692778 -0400 backupd Claim D188EE79-C70B-4646-99A9-0A1E79335461 granted in server
default 11:39:50.692873 -0400 backupd Claim D188EE79-C70B-4646-99A9-0A1E79335461 invoked in client
error 11:39:50.693799 -0400 backupd Failed to write unlock record UUIDs as extended attribute for disk '/', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"
default 11:39:50.914998 -0400 backupd Claim D188EE79-C70B-4646-99A9-0A1E79335461 was revoked
default 11:44:35.826824 -0400 backupd Received claim 39911378-BB4E-42AF-A839-C62DC7DEEEB5
default 11:44:35.826945 -0400 backupd Claim 39911378-BB4E-42AF-A839-C62DC7DEEEB5 granted in server
default 11:44:35.826995 -0400 backupd Claim 39911378-BB4E-42AF-A839-C62DC7DEEEB5 invoked in server
default 11:44:35.833957 -0400 backupd Claim 39911378-BB4E-42AF-A839-C62DC7DEEEB5 was revoked
default 11:45:18.973682 -0400 backupd Received claim E11C98A3-C80F-46E5-8A56-4B33C48F1F33
default 11:45:18.973902 -0400 backupd Claim E11C98A3-C80F-46E5-8A56-4B33C48F1F33 granted in server
default 11:45:18.973963 -0400 backupd Claim E11C98A3-C80F-46E5-8A56-4B33C48F1F33 invoked in server
default 11:45:25.891289 -0400 backupd Received claim 00652E0E-221C-4AC0-8D95-1ADF996165D1
default 11:45:37.036447 -0400 backupd Claim 00652E0E-221C-4AC0-8D95-1ADF996165D1 granted in server
default 11:45:37.036508 -0400 backupd Claim 00652E0E-221C-4AC0-8D95-1ADF996165D1 invoked in server
default 11:45:37.037243 -0400 backupd Claim E11C98A3-C80F-46E5-8A56-4B33C48F1F33 was revoked
default 11:45:37.038338 -0400 backupd Claim 00652E0E-221C-4AC0-8D95-1ADF996165D1 was revoked
default 11:46:08.460119 -0400 backupd Received claim D06FCAD1-0758-42E6-BF67-37B93C84ACA5
default 11:46:08.548835 -0400 backupd Claim D06FCAD1-0758-42E6-BF67-37B93C84ACA5 granted in server
default 11:46:08.549036 -0400 backupd Claim D06FCAD1-0758-42E6-BF67-37B93C84ACA5 invoked in server
default 11:46:11.098889 -0400 backupd Received claim 29B973CE-B314-4614-A1B5-CEB38B2B8AEC
default 11:46:11.147519 -0400 backupd Claim 29B973CE-B314-4614-A1B5-CEB38B2B8AEC granted in server
default 11:46:11.147632 -0400 backupd Claim 29B973CE-B314-4614-A1B5-CEB38B2B8AEC invoked in server
default 11:46:11.147968 -0400 backupd Claim D06FCAD1-0758-42E6-BF67-37B93C84ACA5 was revoked
default 11:46:11.150825 -0400 backupd Claim 29B973CE-B314-4614-A1B5-CEB38B2B8AEC was revoked
default 11:46:32.162004 -0400 backupd Received claim 36FD92BE-CC55-4F05-9D66-EFE7B6DB1005
default 11:46:32.203506 -0400 backupd Claim 36FD92BE-CC55-4F05-9D66-EFE7B6DB1005 granted in server
default 11:46:32.203568 -0400 backupd Claim 36FD92BE-CC55-4F05-9D66-EFE7B6DB1005 invoked in server
default 11:46:32.204046 -0400 backupd Received claim 278996F0-3137-4ABA-94FE-1237D279783B
default 11:46:32.204144 -0400 backupd Claim 278996F0-3137-4ABA-94FE-1237D279783B granted in server
default 11:46:32.204196 -0400 backupd Claim 278996F0-3137-4ABA-94FE-1237D279783B invoked in server
default 11:46:32.205382 -0400 backupd Claim 36FD92BE-CC55-4F05-9D66-EFE7B6DB1005 was revoked
default 11:46:32.206271 -0400 backupd Claim 278996F0-3137-4ABA-94FE-1237D279783B was revoked
default 11:46:32.561043 -0400 backupd Received claim 7CEA6A28-9C36-4BDB-BA46-58D4605C41E1
default 11:46:32.561828 -0400 backupd Claim 7CEA6A28-9C36-4BDB-BA46-58D4605C41E1 granted in server
default 11:46:32.561939 -0400 backupd Claim 7CEA6A28-9C36-4BDB-BA46-58D4605C41E1 invoked in server
default 11:46:32.596785 -0400 backupd Claim 7CEA6A28-9C36-4BDB-BA46-58D4605C41E1 was revoked
default 11:46:32.797513 -0400 backupd Received claim 0723F543-8E7C-4D8B-926E-E213E21BCA74
default 11:46:32.797837 -0400 backupd Claim 0723F543-8E7C-4D8B-926E-E213E21BCA74 granted in server
default 11:46:32.798016 -0400 backupd Claim 0723F543-8E7C-4D8B-926E-E213E21BCA74 invoked in server
default 11:46:32.801157 -0400 backupd Claim 0723F543-8E7C-4D8B-926E-E213E21BCA74 was revoked
default 11:46:34.748347 -0400 backupd Received claim 17CF95D6-5A1D-4FCB-BF6D-FC9822B50DA7
default 11:46:34.748447 -0400 backupd Claim 17CF95D6-5A1D-4FCB-BF6D-FC9822B50DA7 granted in server
default 11:46:34.748835 -0400 backupd Claim 17CF95D6-5A1D-4FCB-BF6D-FC9822B50DA7 invoked in server
default 11:46:34.749883 -0400 backupd Claim 17CF95D6-5A1D-4FCB-BF6D-FC9822B50DA7 was revoked
default 11:46:38.157076 -0400 backupd Received claim 412C1FE0-B6C2-4A8E-AE56-78456B3B0F96
default 11:46:38.157335 -0400 backupd Claim 412C1FE0-B6C2-4A8E-AE56-78456B3B0F96 granted in server
default 11:46:38.157392 -0400 backupd Claim 412C1FE0-B6C2-4A8E-AE56-78456B3B0F96 invoked in server
default 11:46:38.159876 -0400 backupd Claim 412C1FE0-B6C2-4A8E-AE56-78456B3B0F96 was revoked
default 11:49:35.790475 -0400 backupd Received claim C18AEA1A-906F-470A-B630-6DB8E35F6906
default 11:49:35.790553 -0400 backupd Claim C18AEA1A-906F-470A-B630-6DB8E35F6906 granted in server
default 11:49:35.790587 -0400 backupd Claim C18AEA1A-906F-470A-B630-6DB8E35F6906 invoked in server
default 11:49:35.791724 -0400 backupd Claim C18AEA1A-906F-470A-B630-6DB8E35F6906 was revoked
Best Answer
Rebooting seems to have cleared up the problem.
The first backup after the reboot was huge: 937 MB (most of my backups are under 30 MB).
An hour later it did a 4MB backup.