It’s a common question many computer users have – is it really necessary to safely eject a hard drive before disconnecting it? Won’t simply unplugging it work just as well? In this article, we’ll explore the pros and cons of ejecting vs not ejecting drives before disconnecting them.
What Happens When You Don’t Eject a Drive
When you connect an external hard drive to your computer, the operating system mounts the drive. This means your computer establishes a connection to the drive and assigns it a drive letter. It also loads drivers required to communicate with the drive hardware.
Behind the scenes, your operating system is keeping track of writes to the drive. Any files you copy or save get added to a queue waiting to be written to the drive. The OS optimizes this by collecting data in its cache and writing it to the drive in larger chunks.
If you disconnect the drive before ejecting it, all the data waiting in the queue and cache doesn’t get written. Your computer expects the drive to still be connected, but now it’s gone. This can lead to data loss or corruption.
Your computer uses the eject option to flush all pending writes to the drive and disconnect it cleanly without data loss. It also unmounts the drive and disconnects it from the filesystem.
When is it OK to Unplug a Drive Without Ejecting?
Safely ejecting drives is always the recommended option. However, there are some cases where you may be able to get away with unplugging a drive without ejecting:
- The drive is not actively being written to – If you haven’t copied files to the drive or made changes that would trigger writes, unplugging will likely be OK.
- The drive is powered off – External hard drives and USB flash drives that are powered off can often be unplugged safely.
- Using a Mac – Mac OS is generally more resilient to improper drive disconnects than Windows.
- The hardware supports hot swapping – Higher end hardware like RAID arrays and enclosures designed for hot swapping can handle surprise removals.
However, there’s still a risk of data loss or corruption. Safely ejecting minimizes that risk.
Why You Should Avoid Unplugging Drives Without Ejecting
Although you may get away with unplugging a drive without ejecting in some cases, it’s still not recommended. Here are some key reasons why:
- Data loss – Unwritten data in caches and queues gets lost when a drive is suddenly unplugged. Important files may disappear.
- Corruption – Partially written data can get corrupted when disconnected early, making files unusable.
- Drive errors – Drives that aren’t ejected properly may not remount properly when reconnected, requiring a reboot or format.
- System instability – Hanging processes, kernel panics and system crashes can occur when devices suddenly disappear.
While you may get lucky and avoid issues some of the time, it’s only a matter of time before improper drive ejection causes problems. Developing the habit of always ejecting prevents headaches down the road.
How to Safely Eject Drives
Ejecting drives before disconnecting them is a simple process that only takes a few seconds. Here are some ways to eject drives depending on your operating system:
On Windows
- Click the Safely Remove Hardware icon in the system tray and select the drive.
- Right-click the drive in File Explorer and choose Eject.
- Use the USB Safely Remove hardware tray icon in the notification area.
- Use the Eject option in File Explorer’s context menu for the drive.
On Mac OS
- Drag the drive icon on the desktop to the trash.
- Right-click the drive icon on the desktop and select Eject.
- Click the Eject button next to the drive in the Finder sidebar.
- Use the Finder’s File > Eject menu option.
On Linux
- Use the “Safely Remove Drive” option in your desktop environment.
- Run the “eject” command in the terminal.
- Right-click the drive icon and choose Eject or Safely Remove.
- Use the umount command to disconnect the drive from the filesystem.
Best Practices for Removing Drives
Follow these best practices to safely remove drives and prevent data loss:
- Close files/programs – Close any open files and programs accessing the drive before ejecting.
- Eject each drive – If you have multiple drives, eject each individually.
- Wait for the OK – Wait for the confirmation that it’s safe to disconnect after ejecting.
- Disconnect carefully – Unplug the drive gently without putting stress on the connector.
- Don’t interrupt ejects – Never disconnect a drive in the process of ejecting.
Using The Command Line for Disk Management
Advanced users can also manage drive ejection and disconnection using command line tools like diskpart and fsutil on Windows, umount on Linux and diskutil on Mac OS. This allows ejection to be automated through scripts and commands.
Some examples include:
Windows
diskpart list volume // View volumes select volume x // Where x is the drive number detach volume // Detach volume for safe removal exit
fsutil volume diskfree X: // Flush and lock volume // X: is now safe to disconnect
Linux
umount /mnt/drivename // Unmount drive from filesystem
Mac OS
diskutil unmountDisk force /dev/drivename // Unmount drive
This allows administrators to integrate drive ejection into workflows and scripts to ensure consistency.
Using Hardware Disk Eject Buttons
Many drives have a small button or lever to electrically disconnect them quickly. However, you should avoid relying solely on these instead of properly ejecting through software first. The hardware disconnect cuts power immediately without flushing caches, increasing the likelihood of data loss or corruption.
Disabling Auto-Mount on Drive Connection
You can also disable auto-mounting of drives on connection for more control. This prevents the OS from automatically assigning drive letters and mounting volumes when drives are connected. You must then manually mount the drives when needed.
While more inconvenient, this prevents unexpected drive letter changes and avoids automatic writes that may occur from auto-mounting. The drive also won’t be in use by the OS unless you mount it, preventing data loss from disconnecting without ejecting.
Ejecting Drives on Shut Down or Restart
You don’t need to manually eject drives when shutting a computer down. The OS automatically ejects all mounted volumes safely as part of the shutdown process. However, you should still eject external drives as a precaution before restarting the computer.
When to Reformat After Unplugging Without Ejecting
If you realize after the fact that you disconnected a drive without ejecting, don’t panic. The drive will often remount just fine on reconnection. However, if you notice issues like not showing up properly or getting errors, a reformat is recommended.
A full reformat cleans up any filesystem corruption that may have occurred from the improper disconnection. This provides a fresh start without lingering filesystem issues that could cause problems down the road.
Using Encrypted Drives
With encrypted drives, it’s even more critical to eject before disconnecting. The encryption and decryption processes require closing open files and unmounting drives properly to avoid potential corruption of encrypted data.
Unexpectedly removing encrypted drives could lead to complete data loss depending on the encryption used. Filesystem level encryption like Bitlocker relies on filesystem structures that can get corrupted. Software encrypted containers need to be cleanly closed and synced first.
Ejecting Flash Drives and SD Cards
The same ejection rules apply to smaller removable storage like USB flash drives and memory cards. However, the lighter weight makes it easy to accidentally disconnect them without ejecting first. To avoid issues, get in the habit of right-click, eject whenever you’re done accessing a flash drive or memory card.
Using Extra Ports and Hubs
If you regularly connect multiple external drives, use a powered USB hub to avoid needing to disconnect drives as often. This provides extra ports so you can keep drives connected. Just remember to eject the drives before powering down the hub.
You can also add extra eSATA, USB or Thunderbolt ports to your computer through expansion cards to keep drives permanently connected. Just be sure to eject through software before restarting the computer.
Disabling Write-Caching on External Drives
Some external hard drives use write-caching to boost performance. This caches data to be written in the drive’s memory buffer before writing it to disk later. However, this increases the risk of data loss on disconnect. Disabling write caching eliminates this risk.
Using Uninterruptible Power Supplies
Using a UPS (uninterruptible power supply) with devices that have external drives connected ensures drives won’t disconnect unexpectedly if power is lost. The battery backup gives you time to properly shut down the system and eject drives.
Avoiding Drive Disconnects with Laptops
Laptop users face increased risks of disconnecting drives without ejecting first. Putting a laptop to sleep or hibernation doesn’t eject connected drives. Don’t move a laptop or disconnect drives without ejecting them first.
Setting your laptop to request confirmation before sleeping prevents it from unexpectedly sleeping with drives still mounted. This reminds you to properly eject them first.
Using Modern Storage Protocols Like NVMe and Thunderbolt
Newer storage connectivity standards like NVMe and Thunderbolt automatically handle flush commands, making unplugging without ejecting less risky. However, it’s still a bad habit with these. Get used to always ejecting first.
How Unplugging Without Ejecting Affects Other Devices
Along with external hard drives, unplugging without ejecting also applies to:
- USB flash drives and SD cards
- Smartphones and tablets
- External SSDs
- USB card readers and floppy drives
- RAID drive enclosures and multiport hubs
- External optical drives like DVD and Blu-Ray
Any removable storage faces the same potential for data loss or corruption when disconnected improperly. Always eject first.
Conclusion
Is it OK to unplug an external drive without ejecting first? While you may get away with it in some circumstances, there’s always a risk of data loss or corruption. Make properly ejecting drives a habit to avoid losing valuable photos, documents and other data.
The few seconds it takes to safely stop a drive first ends up saving time and frustration down the road. Don’t take shortcuts – always eject your drive first before unplugging it.
