Published 2022-04-18 by TechNet New England
The "Disk Not Ejected Properly" notification appears when macOS loses connection to an external drive unexpectedly. This can happen with USB drives, external SSDs, SD cards, and even internal drives on rare occasions. ## Common Causes **USB hub power issues.** USB hubs, especially unpowered ones, may not provide enough power to keep external drives connected. **Cable issues.** A loose, damaged, or low-quality cable can cause intermittent disconnections. **macOS power management.** macOS aggressively manages power and may disconnect external drives to save energy. **Sleep/wake cycle.** External drives often disconnect when the Mac goes to sleep and may not reconnect cleanly on wake. ## Fix 1: Use a Better Cable or Port Try a different cable. Try connecting directly to the Mac instead of through a hub. If using a USB-C adapter, try a different adapter. ## Fix 2: Disable Power Nap Power Nap performs background tasks during sleep, which can cause drives to wake and disconnect. **Intel Macs:** 1. Go to **System Settings > Energy Saver** (or Battery). 2. Uncheck **Enable Power Nap**. **Apple Silicon Macs:** Power Nap is managed automatically. Instead, try Fix 3. ## Fix 3: Prevent Sleep If the drive disconnects during sleep: 1. Go to **System Settings > Displays > Advanced**. 2. Toggle off **Prevent automatic sleeping when the display is off** if you need the drive to stay connected. Or use the Terminal command: ```bash caffeinate -s & ``` This prevents the Mac from sleeping until you close Terminal. ## Fix 4: Use a Powered USB Hub If you use a USB hub, switch to a powered hub that provides its own power source. Unpowered hubs split the Mac's USB power, which may not be enough for bus-powered drives. ## Fix 5: Check Disk Health The drive itself may be failing. 1. Open **Disk Utility** (Applications > Utilities > Disk Utility). 2. Select the external drive. 3. Click **First Aid > Run**. 4. If Disk Utility finds errors it cannot repair, the drive may need to be replaced. ## Fix 6: Reformat the Drive If the drive's file system is corrupted: 1. Back up any important data first. 2. In Disk Utility, select the drive and click **Erase**. 3. Choose **APFS** (for Mac only) or **ExFAT** (for Mac and Windows compatibility). 4. Click **Erase**. ## When to Contact IT If this happens with an organization-provided drive or if the drive contains important work data, contact IT before reformatting. They can check the drive health and recover data if needed.