Incident: External Drive Partitioning Error in Mac OS X Mountain Lion

Published Date: 2012-10-08

Postmortem Analysis
Timeline 1. The software failure incident with external drives encountering partitioning errors on Mac computers happened in 2012. [15044]
System 1. External hard drives used with Mac computers running Mountain Lion (OS X 10.8) [15044]
Responsible Organization 1. The software failure incident was caused by a bug in OS X Mountain Lion that resulted in partitioning errors and the inability to access data on large external drives connected to Mac computers [15044].
Impacted Organization 1. Mac users encountering partitioning errors and inability to access data on large external drives when using them with Mountain Lion [15044]
Software Causes 1. Bug in OS X causing partitioning errors and inaccessibility of data on large external drives [15044]
Non-software Causes 1. Use of specific makes and models of large external drives with Mountain Lion OS X [15044]
Impacts 1. Inaccessibility of drives: The software failure incident resulted in drives becoming inaccessible to users, leading to data loss and the inability to perform backups [15044]. 2. Partitioning errors: Users encountered partitioning errors when using certain drives with Mountain Lion, causing issues with accessing data and performing necessary operations on the drives [15044]. 3. Limited time before recurrence: Even after attempting to fix the drives by repartitioning and reformatting, there was a limited time before the drives became inaccessible again, indicating a recurring issue [15044].
Preventions 1. Using alternative driver management tools like DiskWarrior, TechTool Pro, or Drive Genius to diagnose and fix hard drive problems could have potentially prevented the software failure incident [15044]. 2. Adjusting drive sleep options to prevent conflicts that may occur when the drive goes into low power modes could have helped in avoiding the issue. Ensuring the option to "put hard disks to sleep when possible" is unchecked in the Energy Saver system preferences and using manufacturer utilities to adjust sleep and power efficiency modes for the drives could have been beneficial [15044].
Fixes 1. Replace the drive with a new one (you might try a different make and model) to see if the problem persists [15044]. 2. Use alternative driver management tools such as DiskWarrior, TechTool Pro, or Drive Genius to diagnose and fix the hard-drive problems [15044]. 3. Adjust drive sleep options by ensuring the option to "put hard disks to sleep when possible" is unchecked in the Energy Saver system preferences and installing utilities from drive manufacturers to adjust sleep and power efficiency modes [15044].
References 1. Apple discussion poster Avendanio [15044]

Software Taxonomy of Faults

Category Option Rationale
Recurring one_organization (a) The software failure incident related to partitioning errors and the inability to access data on large external drives has happened again within the same organization (Apple). Users reported encountering the error "Error: Partition map repair failed while adjusting structures to fit current whole disk size" when using some drives in Mountain Lion, leading to drive inaccessibility despite no partitioning being performed. The issue persisted even after reformatting and connecting the drives to different versions of OS X [15044]. (b) The software failure incident of partitioning errors and drive inaccessibility with large external drives has not been reported to have happened at multiple organizations. The article suggests that the issue may be specific to certain makes and models of drives when used with Mountain Lion, or could be due to a bad batch of drives. Users are advised to try replacing the drive with a new one or using alternative driver management tools to address the problem [15044].
Phase (Design/Operation) design (a) The software failure incident described in the article is related to the design phase. The issue with large external drives encountering partitioning errors and becoming inaccessible on Mac computers running Mountain Lion is attributed to a bug in the operating system. Users have reported encountering errors such as "Error: Partition map repair failed while adjusting structures to fit current whole disk size" without performing any partitioning actions on the drives. This indicates that the problem is likely due to contributing factors introduced during the system development or system updates, specifically related to how Mountain Lion interacts with certain drive makes and models [15044]. (b) The software failure incident is not directly linked to operation or misuse of the system. The reported issues with external drives on Mac computers running Mountain Lion are more likely a result of a bug in the OS rather than user error or misuse. Users have experienced problems with drive accessibility and partitioning errors even when following standard procedures, indicating that the root cause lies in the system design or development rather than operational factors [15044].
Boundary (Internal/External) within_system The software failure incident described in the article is related to the boundary of the system. The issue with large external drives encountering partitioning errors and becoming inaccessible on Mac systems running Mountain Lion is attributed to potential bugs within the OS X operating system [15044]. The error message "Error: Partition map repair failed while adjusting structures to fit current whole disk size" indicates an internal issue within the system that affects the drives' accessibility and functionality. Additionally, the suggested fixes such as replacing the drive, using alternative driver management tools, and adjusting drive sleep options all point towards addressing issues originating from within the system itself.
Nature (Human/Non-human) non-human_actions (a) The software failure incident occurring due to non-human actions: The software failure incident described in the article is related to a bug encountered by Mac users when using large external drives with Mountain Lion. The bug causes partitioning errors and the inability to access data on the drives, even though no partitioning of the drive has been performed. This bug seems to be a software issue introduced without human participation, as users are facing the problem without making any changes to the drive themselves. The error message "Error: Partition map repair failed while adjusting structures to fit current whole disk size" indicates a failure in the software's ability to handle the drives properly, leading to their inaccessibility [15044]. (b) The software failure incident occurring due to human actions: The software failure incident described in the article does not indicate any contributing factors introduced by human actions that led to the bug affecting the drives. Users are simply connecting their drives to Mac computers running Mountain Lion, and the issue arises without any specific actions taken by the users themselves. Therefore, the failure does not seem to be a result of human actions [15044].
Dimension (Hardware/Software) hardware (a) The software failure incident reported in Article 15044 is related to hardware. The incident involves issues with large external drives connected to Mac computers, specifically in the context of using them with Mountain Lion OS. Users have encountered partitioning errors and the inability to access data on the drives, leading to the drives becoming inaccessible. The error message "Error: Partition map repair failed while adjusting structures to fit current whole disk size" indicates a problem with the drive's partitioning, which is a hardware-related issue. Users have tried reformatting the drives and using different versions of Disk Utility, but the problem persists, suggesting a hardware-related bug or compatibility issue with specific drive makes and models [15044].
Objective (Malicious/Non-malicious) non-malicious (a) The software failure incident described in the article is non-malicious. It is related to a bug in which using certain large external drives in Mountain Lion results in partitioning errors and the inability to access data on the drives. Users encounter errors like "Error: Partition map repair failed while adjusting structures to fit current whole disk size" even though no partitioning of the drive has been performed. The issue seems to be a bug in OS X that affects specific makes and models of drives when used with Mountain Lion, leading to drive inaccessibility and data loss [15044].
Intent (Poor/Accidental Decisions) accidental_decisions The software failure incident described in Article 15044 seems to be more related to accidental_decisions. The issue with large external drives encountering partitioning errors and becoming inaccessible on Mac computers running Mountain Lion appears to be a result of unintended consequences or mistakes rather than poor decisions. Users are facing errors like "Error: Partition map repair failed while adjusting structures to fit current whole disk size" without intentionally making any changes to the drive partitions. Additionally, the suggested fixes involve troubleshooting steps and workarounds to address the problem rather than addressing poor decisions made during the development or implementation of the software.
Capability (Incompetence/Accidental) development_incompetence (a) The software failure incident described in the article seems to be more related to development incompetence. Users encountered a bug in which using certain drives in Mountain Lion resulted in partitioning errors and the inability to access data on the drives. Despite no partitioning of the drive being performed, an error message stating "Error: Partition map repair failed while adjusting structures to fit current whole disk size" appeared. Additionally, even though some drives worked fine after repartitioning and formatting, others continued to show the same error when checked with Disk Utility, indicating a potential issue with the software's handling of drive structures [15044].
Duration temporary The software failure incident described in the article is temporary. Users encountered an apparent bug in which using some drives in Mountain Lion resulted in partitioning errors and the inability to access data on the drives. The drives became inaccessible and showed errors like "Error: Partition map repair failed while adjusting structures to fit current whole disk size." However, in some instances, the drive worked fine after repartitioning and formatting, indicating that the issue was not permanent [15044].
Behaviour 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. Instead, the issue involves partitioning errors and the inability to access data on drives when using them with Mountain Lion [15044]. (b) omission: The software failure incident is not related to a failure of the system omitting to perform its intended functions at an instance(s). The issue described involves errors in partitioning and accessing data on drives, rather than the system omitting any specific functions [15044]. (c) timing: The software failure incident is not related to a failure of the system performing its intended functions correctly but too late or too early. The issue discussed in the article pertains to partitioning errors and drive inaccessibility, not timing-related problems [15044]. (d) value: The software failure incident is not related to a failure of the system performing its intended functions incorrectly. The issue described involves partitioning errors and drive inaccessibility, rather than the system executing functions incorrectly [15044]. (e) byzantine: The software failure incident is not related to a byzantine failure where the system behaves erroneously with inconsistent responses and interactions. The issue discussed in the article pertains to partitioning errors and drive inaccessibility, rather than erratic or inconsistent behavior of the system [15044]. (f) other: The behavior of the software failure incident is related to partitioning errors and the inability to access data on drives when using them with Mountain Lion. Users encounter errors like "Error: Partition map repair failed while adjusting structures to fit current whole disk size," leading to drive inaccessibility despite no partitioning being performed. The issue may be specific to certain drive makes and models with Mountain Lion, suggesting a potential bug in the OS [15044].

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 (a) death: There is no mention of any deaths resulting from the software failure incident in the provided article [15044]. (b) harm: The software failure incident did not result in any physical harm to individuals as per the article [15044]. (c) basic: The software failure incident did not impact people's access to food or shelter as per the article [15044]. (d) property: People's material goods, specifically external hard drives, were impacted due to the software failure incident. Users encountered partitioning errors and the inability to access data on the drives [15044]. (e) delay: Users had to deal with the inconvenience of their drives becoming inaccessible and encountering partitioning errors, which could potentially lead to delays in accessing important data stored on those drives [15044]. (f) non-human: Non-human entities, specifically external hard drives, were impacted by the software failure incident as users faced issues with drive accessibility and partitioning errors [15044]. (g) no_consequence: The software failure incident had observable consequences on users' external hard drives, leading to accessibility issues and partitioning errors [15044]. (h) theoretical_consequence: The article does not discuss potential consequences that did not actually occur as a result of the software failure incident [15044]. (i) other: The software failure incident did not result in any other specific consequences beyond the impact on users' external hard drives as described in the article [15044].
Domain information (a) The software failure incident reported in Article 15044 is related to the information industry. The incident involves issues with using large external drives on Mac computers for storing data libraries and backups, specifically mentioning iTunes and iPhoto data libraries and Time Machine backups. Users encountered partitioning errors and the inability to access data on the drives, indicating a problem with data storage and management within the information industry [15044].

Sources

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