Wednesday, February 10, 2016 [Tweets] [Favorites]

Benign Neglect of Time Machine

John Martellaro (via Katie Floyd):

Apple’s Time Machine backup system was born in a time (2006) when Apple realized that customers weren’t routinely backing up their Macs. So a simple, stopgap system, with some novel features, was devised for the novice user. Unfortunately, over the years, the app hasn’t progressed and kept pace with modern user needs. Today, most every tech writer says: Use it, but don’t trust it completely. This is an unfortunate situation.

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For example, Time Machine doesn’t, in normal operation, create a bootable backup of the internal drive. It can only restore a damaged (or new) internal drive from the Time Machine archive.

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Next, there is no easily digestible, user accessible log file available for inspection within the Time Machine System Preference.

[…]

Finally, there is very little in the way of diagnostics or feedback to the user about the integrity of each backup. In other words, the user has no usable tools within Time Machine. that can be used to verify the integrity of the current backup other than a casual visual inspection. If a Time Machine backup gets hung up or mangled, most users are left in the dark and find themselves forced to start all over, regretting that a possible valuable archive needs to be overwritten.

3 Comments

At this point I'm more afraid of Apple "improving" Time Machine than neglecting it.

"At this point I'm more afraid of Apple "improving" Time Machine than neglecting it."

It's funny, cuz it's true.

One new feature added to Time Machine is basic checksum functionality. From the tmutil man page:

verifychecksums path ...
Compute a checksum of data contained within a backup and verify the result(s) against checksum informa-
tion computed at the time of backup.

No output is generated for matching checksums. Issues are reported using the following legend:

! The file's current checksum does not match the expected recorded checksum.
? The file's recorded checksum is invalid.

Beginning in OS X 10.11, Time Machine records checksums of files copied into snapshots. Checksums are
not retroactively computed for files that were copied by earlier releases of OS X.

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