5 Replies Latest reply: Oct 6, 2012 6:34 AM by Linc Davis
mrc3 Level 1 (0 points)

Running 10.8.2


I have a 2TB internal primary (boot) drive, and a 2TB internal dirve that is the Time Machine drive.


The primary disk is about 50% full.


I've experienced problems with this setup since 10.7.


Time Machine will repeatedly fail with a dialog box stating the disk is unexpectedly full.


I'm OK with whatever level of backup TM can maintain, 4 months, 4 weeks, 4 hours, until the second disk is full.


But it seems the free space on the TM drive isn't properly managed.


The only thing I can do to fix for a while is wipe and reformat the TM drive.


What am I missing?

PowerMac, OS X Mountain Lion (10.8.2), 8GB 4TB
  • Linc Davis Level 10 (184,745 points)

    If you have more than one user account, these instructions must be carried out as an administrator.

    Launch the Console application in any of the following ways:

    ☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

    ☞ In the Finder, select Go Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

    ☞ Open LaunchPad. Click Utilities, then Console in the icon grid.

    Make sure the title of the Console window is All Messages. If it isn't, select All Messages from the SYSTEM LOG QUERIES menu on the left.

    Enter the word "Starting" (without the quotes) in the String Matching text field. You should now see log messages with the words "Starting * backup," where * represents any of the words "automatic," "manual," or "standard." Note the timestamp corresponding to the last failed backup. Clear the text field and scroll back in the log to that time. Post the messages timestamped from then until the end of that backup.

    Post the log text, please, not a screenshot. If there are runs of repeated messages, post only one example of each. Don't post many repetitions of the same message.

    When posting a log extract, be selective. Don't post more than is requested.

    Please do not indiscriminately dump thousands of lines from the log into a message.


    Some personal information, such as the names of your files, may be included — edit that out, too, but don’t remove the context.

  • mrc3 Level 1 (0 points)

    Thanks for your response.  Here's the info:


    10/6/12 5:59:19.653 AM com.apple.backupd[37710]: Starting automatic backup

    10/6/12 5:59:19.657 AM com.apple.backupd[37710]: Backing up to: /Volumes/Disk2/Backups.backupdb

    10/6/12 5:59:44.842 AM com.apple.backupd[37710]: Using file event preflight for Disk1

    10/6/12 6:01:24.374 AM com.apple.backupd[37710]: Will copy (4.2 GB) from Disk1

    10/6/12 6:01:24.850 AM com.apple.backupd[37710]: Found 16153 files (6.58 GB) needing backup

    10/6/12 6:01:24.950 AM com.apple.backupd[37710]: 9.82 GB required (including padding), 12.56 GB available

    10/6/12 6:07:23.386 AM KernelEventAgent[43]: tid 00000000 received event(s) VQ_LOWDISK (4)

    10/6/12 6:07:23.386 AM KernelEventAgent[43]: tid 00000000 type 'hfs', mounted on '/Volumes/Disk2', from '/dev/disk2s2', low disk

    10/6/12 6:07:23.000 AM kernel[0]: HFS: Low Disk: Vol: Disk2 freeblks: 38391, warninglimit: 38400

    10/6/12 6:07:37.494 AM KernelEventAgent[43]: tid 00000000 received event(s) VQ_LOWDISK, VQ_VERYLOWDISK (516)

    10/6/12 6:07:37.494 AM KernelEventAgent[43]: tid 00000000 type 'hfs', mounted on '/Volumes/Disk2', from '/dev/disk2s2', low disk, very low disk

    10/6/12 6:07:37.000 AM kernel[0]: HFS: Vol: Disk2 Very Low Disk: freeblks: 25577, dangerlimit: 25600

    10/6/12 6:07:37.525 AM mds[37]: (Warning) Volume: Indexing reset and suspended on backup volume "/Volumes/Disk2" because it is low on disk space.

    10/6/12 6:08:35.387 AM KernelEventAgent[43]: tid 00000000 received event(s) VQ_LOWDISK (4)

    10/6/12 6:08:35.387 AM KernelEventAgent[43]: tid 00000000 type 'hfs', mounted on '/Volumes/Disk2', from '/dev/disk2s2', low disk

    10/6/12 6:08:35.600 AM com.apple.backupd[37710]: Stopping backup.

    10/6/12 6:08:35.670 AM com.apple.backupd[37710]: Error: (-34) SrcErr:NO Copying /Users/mark/_CRITICAL/HD_120.dmg to /Volumes/Disk2/Backups.backupdb/bryn/2012-10-01-100402.inProgress/A82AA1F9-9FF1 -4918-8456-F1359D2A4D7A/Disk1/Users/mark/_CRITICAL

    10/6/12 6:08:35.906 AM com.apple.backupd[37710]: Copied 14758 files (123.12 GB) from volume Disk1.

    10/6/12 6:08:35.906 AM com.apple.backupd[37710]: Copy stage failed with error:28

    10/6/12 6:08:47.216 AM com.apple.backupd[37710]: Backup failed with error: 28


    HD_120.dmg is a 120GB disk image.

  • Linc Davis Level 10 (184,745 points)

    HD_120.dmg is a 120GB disk image.


    Read/write or read-only?

  • mrc3 Level 1 (0 points)


  • Linc Davis Level 10 (184,745 points)

    You won't get good results from trying to back up such a large file with TM. Every time it changes, the whole thing has to be copied, quickly filling up any backup volume. It won't be backed up at all while mounted. If it's mounted while being backed up, the backup will fail.


    If you really need to store such a large filesystem on a disk image (which I doubt), use a sparsebundle, which consists of many small files instead of one big one. You still won't be able to back it up while it's mounted, though.


    Disk images have typically been used to encrypt files. In OS X 10.7 and later, you can encrypt any HFS volume, including a boot volume, so there's no longer much need for encrypted disk images with their considerable disadvantages.