Incident: Time Machine Bug Prevents Recent Backups for Full Restore.

Published Date: 2013-06-04

Postmortem Analysis
Timeline 1. The software failure incident with Apple's Time Machine backup routines in Mountain Lion was reported on 2013-06-04 [19641]. Therefore, the software failure incident happened in June 2013.
System The system that failed in the software failure incident described in Article 19641 is: 1. Apple's Time Machine backup routines in OS X Mountain Lion [19641].
Responsible Organization 1. Apple's Time Machine backup routines in Mountain Lion were responsible for causing the software failure incident [19641].
Impacted Organization 1. Users of Apple's Time Machine backup routines in OS X Mountain Lion [19641]
Software Causes 1. Bug in Apple's Time Machine backup routines in OS X Mountain Lion [19641]
Non-software Causes 1. Hardware failure in the backup drive. 2. Corruption in the Time Machine preferences file. 3. Configuration issue in the Time Machine system preferences. [19641]
Impacts 1. The software failure incident in Apple's Time Machine backup routines in OS X Mountain Lion prevented recent backups from being used for a full restore, impacting users who relied on these backups for data recovery [19641].
Preventions 1. Regularly testing the Time Machine backup routines in Mountain Lion for potential bugs and issues [19641]. 2. Implementing a more robust error-checking mechanism in the Time Machine preferences file to detect and prevent corruption [19641]. 3. Conducting thorough quality assurance and user acceptance testing before releasing updates to ensure the reliability of the backup system [19641].
Fixes 1. Turn off Time Machine in the Time Machine system preferences 2. Delete the file called "com.apple.TimeMachine.plist" in the Macintosh HD > Library > Preferences folder 3. Start Time Machine in the System Preferences 4. Add your drive as a Time Machine backup destination again 5. Create a new backup instance by choosing "Back Up Now" in the Time Machine menu extra [19641]
References 1. Time Machine backup routines in Apple's OS X Mountain Lion [19641]

Software Taxonomy of Faults

Category Option Rationale
Recurring one_organization (a) The software failure incident related to Time Machine backup bug in OS X Mountain Lion has happened within the same organization, Apple. The bug causing recent backups to not be usable for a full restore was specific to Apple's Time Machine backup routines in Mountain Lion [19641]. This indicates a recurring issue within Apple's software. (b) There is no information provided in the article about the software failure incident happening at multiple organizations or with their products and services.
Phase (Design/Operation) design (a) The software failure incident described in Article 19641 is related to the design phase of the system. The issue with Apple's Time Machine backup routines in OS X Mountain Lion is attributed to a bug that causes corruption in the Time Machine preferences file, preventing recent backups from being recognized as valid for restoration. This bug is a result of the system development or updates, as it affects the functionality of the backup system itself, leading to the inability to use recent backups for a full restore [19641]. (b) There is no specific information provided in the articles about the software failure incident related to the operation phase, such as misuse or operational errors causing the failure. Therefore, the incident primarily falls under the design phase failure category.
Boundary (Internal/External) within_system (a) The software failure incident described in the article is within_system. The issue is related to a bug in Apple's Time Machine backup routines in OS X Mountain Lion that is causing corruption in the Time Machine preferences file, preventing recent backups from being recognized as valid restore points. This bug is causing the backups to not appear in the list of available restore points, impacting the functionality of migration tools like Apple's Setup Assistant and Migration Assistant. The solution provided involves resetting Time Machine and starting over, indicating that the failure is internal to the system itself [19641].
Nature (Human/Non-human) non-human_actions (a) The software failure incident in Article 19641 is related to non-human actions. The issue described in the article is a bug in Apple's Time Machine backup routines in Mountain Lion that is causing corruption in the Time Machine preferences file. This corruption is preventing recent backups from being recognized as valid restore points, impacting the functionality of the backup system and migration tools. The bug is not a result of human actions but rather a technical flaw within the software itself.
Dimension (Hardware/Software) software (a) The software failure incident mentioned in Article 19641 is related to a bug in Apple's Time Machine backup routines in Mountain Lion. This bug is causing corruption in the Time Machine preferences file, which is preventing recent backups from being used for a full restore. The issue is not directly related to hardware but rather to a software bug affecting the backup functionality [19641].
Objective (Malicious/Non-malicious) non-malicious (a) The article does not mention any malicious intent behind the software failure incident. It describes a bug in Apple's Time Machine backup routines in Mountain Lion that is causing issues with recent backups not being usable for a full restore. The failure is attributed to corruption in the Time Machine preferences file, which is preventing more-recent backups from appearing as valid backups for restoration. The article provides steps to check for and address this bug, indicating a non-malicious software failure incident [19641].
Intent (Poor/Accidental Decisions) accidental_decisions The software failure incident described in Article 19641 seems to align more with the category of 'accidental_decisions'. The issue with Apple's Time Machine backup routines in OS X Mountain Lion appears to be a bug or corruption in the Time Machine preferences file that is causing recent backups to not be recognized as valid for restoration. This issue seems to be unintentional and not a result of deliberate poor decisions.
Capability (Incompetence/Accidental) development_incompetence (a) The software failure incident related to development incompetence is evident in the bug found in Apple's Time Machine backup routines in OS X Mountain Lion. The bug causes corruption in the Time Machine preferences file, preventing recent backups from being recognized as valid restore points. This issue not only affects the usability of backups but also hinders migration tools like Apple's Setup Assistant and Migration Assistant from utilizing them. The only known solution to this problem involves resetting Time Machine and starting over, indicating a lack of robustness in the initial development or testing of the backup system [19641]. (b) The accidental nature of the software failure incident is highlighted by the unexpected behavior of Time Machine in OS X Mountain Lion. Users are finding that despite the regular hourly backups, recent backups are not always available for restoration due to corruption in the Time Machine preferences file. This unintended consequence of the backup system points to accidental flaws or oversights in the development or implementation of the software, leading to an unexpected failure scenario [19641].
Duration temporary The software failure incident described in the article is temporary. The issue with Apple's Time Machine backup routines in OS X Mountain Lion is due to a bug causing corruption in the Time Machine preferences file, preventing recent backups from being recognized as valid restore points. Users can reset Time Machine and start over to fix the problem, indicating that the failure is not permanent [19641].
Behaviour omission, value, other (a) crash: The software failure incident described in the article is not related to a crash where the system loses state and does not perform any of its intended functions. (b) omission: The software failure incident is related to the system omitting to perform its intended functions at an instance(s). Specifically, the bug in Apple's Time Machine backup routines in OS X Mountain Lion is causing recent backups to not be listed as valid restore points, preventing users from using them for restoration purposes [19641]. (c) timing: The software failure incident is not related to the system performing its intended functions correctly but too late or too early. (d) value: The software failure incident is related to the system performing its intended functions incorrectly. The corruption in the Time Machine preferences file is causing the backups to not appear as valid backups for use during restoration, impacting the functionality of migration tools like Apple's Setup Assistant and Migration Assistant [19641]. (e) byzantine: The software failure incident is not related to the system behaving erroneously with inconsistent responses and interactions. (f) other: The other behavior related to the software failure incident is that users experiencing this bug have to reset Time Machine and start over as the only known way to fix the issue. This involves turning off Time Machine, deleting a specific file, and adding the backup destination again to make new backups accessible [19641].

IoT System Layer

Layer Option Rationale
Perception None None
Communication None None
Application None None

Other Details

Category Option Rationale
Consequence property, delay, non-human, theoretical_consequence, other (a) death: There is no mention of any deaths resulting from the software failure incident in the provided article [19641]. (b) harm: The article does not mention any physical harm caused to individuals due to the software failure incident [19641]. (c) basic: The incident did not impact people's access to food or shelter [19641]. (d) property: People's material goods, money, or data were impacted as the software failure prevented recent backups from being used for a full restore, affecting the ability to access important data [19641]. (e) delay: Users had to deal with the inconvenience of not being able to use recent backups for restoration, which could potentially cause delays in recovering important data [19641]. (f) non-human: The software failure incident primarily affected the functionality of Apple's Time Machine backup routines in OS X Mountain Lion, impacting data backup and restoration processes [19641]. (g) no_consequence: The article does not mention any real observed consequences of the software failure incident [19641]. (h) theoretical_consequence: The article discusses potential consequences of the software failure, such as preventing backups from being listed as valid restore points and hindering migration tools like Apple's Setup Assistant and Migration Assistant from using them [19641]. (i) other: The software failure incident led to the inconvenience of users having to reset Time Machine and start over to address the issue, impacting their workflow and potentially causing frustration [19641].
Domain information (a) The software failure incident reported in the article is related to the information industry. The issue specifically affects Apple's Time Machine backup routines in OS X Mountain Lion, which are crucial for backing up and restoring data on Mac systems [19641].

Sources

Back to List