Protecting Data: Windows Vista disk diagnostics Nathan Obr

Quantifying Disk Failures Catastrophic disk failures ~200 disks replaced per week at Microsoft in 2003 Top driver of Microsoft support’s hardware- related support calls in both client and server Based on Microsoft figures, disk failures cost many millions of dollars per year in enterprises Localized failures (bad blocks) Kernel and user-mode crashes 1.7% of customer-report Microsoft Online Crash Analysis crashes are due to disk errors Application hangs during read recovery

Disk Failure Mitigations Prevention Hybrid hard disks (mobile systems) RAID Catastrophic failure recovery Data backup Disk replacement Localized failure recovery Repair from redundant copy Restore from backup

Windows Vista Disk Diagnostics Purpose: Save user data before catastrophic disk failure Client SKUs Self Monitoring And Reporting Technology (S.M.A.R.T.) polling triggers diagnostic Uses S.M.A.R.T. trip status – no threshold/attribute comparison Warns user of impending failure and walks them through backup and replacement Windows Vista backup improvements

Disk Diagnostics Details Disk class driver polls S.M.A.R.T. status hourly as it has done since Windows 2000 Based on industry feedback, no use of Disk Self-Test or attribute comparison Failure triggers user-mode code Filter out duplicate failures Log SMART READ LOG details to OS event log Device error count from summary error log sector Life timestamp from most recent error log entry Trigger user-context interactive resolution Customizable by Group Policy Print instructions, walk user through backup