Pattern to record: Problems begin after unplugging, sleep or a loose cable event.

Identify the storage layer

APFS separates the physical device, container and individual volumes. Record which layer fails to appear or mount, and protect required files before changing container metadata or removing snapshots. One possible explanation is that cached changes were not committed before the device disconnected.

Protect data before repair

A reinstall or erase is not a data-recovery first step. Reconnecting repeatedly through the same loose cable risks more corruption.

Evidence to check on the protected copy

1. Protect the physical drive and inspect container, volume and snapshot structure before repair.
2. Stabilise the connection and compare metadata on a read-only image.

Recovery and verification

If the checks support this cause, repair the file system after important data is copied elsewhere. Verification should cover mounting, startup, snapshots, file access, sleep and verified backup.

For an assessment of your Mac computer, contact AEPC in Burswood or call 027 908 8880. Provide the model and the conditions that reproduce this problem. Workshop visits are by appointment.