I have been using Time Machine since its inception. For years, Time Machine caused my backup disks to be bootable. Very convenient for recovery operations.

Recently, I deployed two new Time Machine backup disks. Neither one of them became bootable. What gives?

Two system log messages generated by Time Machine:

2018-12-03 08:18:25.109094-0800 localhost backupd[46577]: (TimeMachine) [com.apple.TimeMachine:TMLogError] Failed to attach '/Volumes/WD Elements 1/Backups.backupdb/.RecoverySets/0/com.apple.recovery.boot/BaseSystem.dmg', error: No such file or directory

I see that there are directories /1/ and /2/,but not /0/. Is this a Time Machine bug?

2018-12-03 07:37:41.017509-0800 localhost backupd[46577]: (TimeMachine) [com.apple.TimeMachine:TMLogError] Failed to write unlock record UUIDs as extended attribute for disk '/', error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

I am concerned that my new backup disks got off to a bad start. Comments?

  • 1
    Is it GUID partitioned? Also try running 'First-Aid' in 'Disk Utility.app' – amdyes Dec 4 '18 at 3:01
  • Hello Arnstein, welcome to Ask Different. I don't remember ever needing to boot from a Time Machine disk, handy feature, but if it worked in the past that's definitively no longer the case. There's nothing wrong with your backup disks.The recommended way to restore macOS is to to start up from macOS Recovery with <command>-R, see support.apple.com/en-us/HT203981. – jaume Dec 4 '18 at 11:08

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