Getting files back

The drive that refuses to leave

Updated 2026-08-08 · 4 min read

Pulling the cable works until the day it corrupts the drive. The eject error has a specific cause every time — a process with a file open on that volume — and macOS will name it if asked properly.

Name the process

lsof /Volumes/DriveName

Every process with anything open on the drive, listed. Quit those apps and eject again. If the list is long, the last-opened app with documents on that drive is usually the one that matters.

The invisible suspect: Spotlight

macOS indexes drives as they mount, and mds holding index files open blocks ejection with no visible app running. Check and stop it:

mdutil -s /Volumes/DriveName
mdutil -i off /Volumes/DriveName

For archive drives that plug in rarely, indexing restarts from scratch each time and rarely finishes — turning it off for those volumes ends both the eject fights and the pointless background churn. (Third-party index-based search tools keep their own records of offline drives precisely because of this.)

Terminal ejection

diskutil unmount /Volumes/DriveName

reports failures with more detail than Finder. The escalation:

diskutil unmountDisk /dev/disk4
diskutil unmountDisk force /dev/disk4

(diskutil list shows which disk number is which.) Force is the last resort before cable-pulling — it abandons open files but flushes what can be flushed, which unplugging does not.

If it happens every time

A backup tool, antivirus scanner, or sync client configured to watch the drive will hold it perpetually. lsof shows the same name each eject; exclude the volume in that app's settings and the problem ends permanently.

Common questions

Is force-ejecting bad for the drive?

It abandons any writes in flight, risking the files being written. It is safer than pulling the cable and worse than quitting the holder.

Why does Time Machine block ejection?

If the drive is a backup destination, backups hold it while running. Wait for completion or skip the backup in the Time Machine menu.