Most problems in Time Machine only become apparent when you go to restore a document from your backup. When it encounters significant errors, Time Machine is supposed to alert the user, but there’s a lot that can go wrong in complete silence. For example, your backups can become very irregular, running hours apart, without your even being aware.

The second beta release of my Time Machine backup analysis tool, The Time Machine Mechanic or T2M2, is much more capable than the first, and is at once very simple to use, and the most sophisticated tool for analysing recent backup activity. The latest release is available from Downloads above.

It has essentially two controls: you set the period, in hours, which you want it to analyse. This now works properly, so that you can type the number in or use the stepper controller to adjust it. Once you have done that, click on the Check Time Machine button, and it will shortly come back with a very detailed analysis of all Time Machine backups made over that period, and set the ‘traffic light’ to green, amber, or red accordingly.

Information provided includes:

• the location of the last backup it made, in both Unix disk terms and its path,
• the amount of free space on that volume at the start of the last backup,
• how many backups it started, and how many completed successfully, over the period,
• the time elapsed since the last backup completed,
• figures on the number of files backed up in total, and the range for each backup,
• a list of the total size of data backed up on each occasion,
• a list of the time periods taken to complete each backup,
• a list of the time intervals between each backup starting,
• the total number of new backups made, and of old backups deleted,
• the number of error messages over the period.

If everything is looking good, T2M2 will give you a ‘green light’, and you can see for yourself that backups have been going well, and without error. There are some indicators which might be more serious, though: if it encounters them, T2M2 will give you an ‘amber light’ and explain in the text. The most common reason for this is that a backup is still in progress. If you wait until it is complete, and check Time Machine again, you should get a ‘green light’.

Significant error messages are one cause of T2M2 showing a ‘red light’, although many errors are not serious. If T2M2 discovers errors messages which might be significant, it displays them for you to read.

This beta version should help you spot irregular backups, but doesn’t yet analyse their cause; that will come in a future version.

You can also save the text report, for reference.

It comes with a detailed PDF document, and is free as ever. I hope that you find it useful: I already have, as it spotted an error and a deep event traversal for me, which Time Machine didn’t report.

Tomorrow I will walk through some of its more useful Swift code…