Because my drive will freeze occasionally, I would have to pull the cable out. (see the question below for more detail):

I've heard that doing so will hurt (or break, in the worst scenario) the drive, so I wonder whether there is a way to force eject a device which would avoid the physical damage. I need to force eject it because the drive (like other ordinary drives) will try to read one block over and over until it reads successfully or reached timeout. When it's stuck trying to read a damaged block, the kernel will block the process/thread until there is a result. The application waiting for I/O will act as if it's stopped, so even using force quit / sigkill won't quit the application. Because the timeout is usually long for home-use HHD, the core GUI component of the system (Finder + Dock) will freeze for a long time, thus preventing normal usage.

Note that force eject a device is not the equivalent as force unmount a partition. Force eject the HDD will make the read/write header land in the parking zone, and the drive will stop spinning.

Edit: I replaced my drive with a new one (same model, actually) and used ddrescue to copy all the data. I did find 3 bad areas that are ~ 1 mb each. ddrescue did freeze when it encounters these bad areas (I'm using raw disk access, i.e. /dev/rdiskX), so it's not a system problem. However, I would still like to know how to force eject a mass storage device when it is stuck.

Below is the etrecheck report:
EtreCheck version: 5.0.5 (5A016)
Report generated: 2019-07-10 18:33:17
Download EtreCheck from https://etrecheck.com
Runtime: 4:41
Performance: Good

Problem: Other problem
HDD freeze

Major Issues:
  Anything that appears on this list needs immediate attention. 
  Time Machine backup out-of-date - The last Time Machine backup is over 10 days old.
  System Integrity Protection disabled - System Integrity Protection is disabled. This computer is at risk of malware infection.
  Kernel panics - This system has experienced kernel panics that could be related to 3rd party software.
  Heavy CPU usage - Some processes are using an unusually high amount of CPU.

Minor Issues:
  These issues do not need immediate attention but they may indicate future problems. 
  Heavy RAM usage - This machine is using a large amount of RAM.
  Apps crashing - There have been numerous app crashes.
  Unsigned files - There are unsigned software files installed. They appear to be legitimate but should be reviewed.
  Abnormal shutdown - Your machine shut down abnormally.

Hardware Information:
  MacBook Pro (13-inch, 2017, Four Thunderbolt 3 ports)
  MacBook Pro Model: MacBookPro14,2
  1 3.1 GHz Intel Core i5 (i5-7267U) CPU: 2-core
  16 RAM - Not upgradeable
    BANK 0/DIMM0 - 8 GB LPDDR3 2133  ok
    BANK 1/DIMM0 - 8 GB LPDDR3 2133  ok
  Battery: Health = Normal - Cycle count = 335

Video Information:
  Intel Iris Plus Graphics 650 - VRAM: 1536 MB
    Color LCD 2880 x 1800

  disk0 - APPLE SSD AP0512J 500.28 GB (Solid State - TRIM: Yes) 
  Internal PCI-Express 8.0 GT/s x4 NVM Express
    disk0s1 - EFI [EFI] 315 MB
    disk0s2 [APFS Container] 499.96 GB
      disk1 [APFS Virtual drive] 499.96 GB (Shared by 4 volumes)
        disk1s1 - M***************a (APFS) (Shared - 457.50 GB used)
        disk1s2 - Preboot (APFS) [APFS Preboot] (Shared - 46 MB used)
        disk1s3 - Recovery (APFS) [Recovery] (Shared - 1.04 GB used)
        disk1s4 - VM (APFS) [APFS VM] (Shared - 17.47 GB used)

  disk2 - Seagate BUP BK 5.00 TB
  External USB 5 Gbit/s USB
    disk2s1 - EFI (MS-DOS FAT32) [EFI] 210 MB
    disk2s2 - S******************) (Journaled HFS+) 5.00 TB (2.08 TB used)

Mounted Volumes:
  disk1s1 - M***************a 499.96 GB (22.69 GB free)
    Mount point: /

  disk1s4 - VM [APFS VM] (Shared - 17.47 GB used)
    Mount point: /private/var/vm

  disk2s2 - S******************) 5.00 TB (2.92 TB free)
    Journaled HFS+
    Mount point: /Volumes/S******************)

  disk4s2 - M***********0 41 MB (16 MB free)
    Mac OS Extended
    Disk Image
    Mount point: /Volumes/M***********0

  Interface en8: Belkin USB-C LAN
    Proxies: HTTP, HTTPS, SOCKS
  Interface en10: iPhone
    Proxies: HTTP, HTTPS, SOCKS
  Interface en0: Wi-Fi

    Proxies: HTTP, HTTPS, SOCKS
  Interface en7: Bluetooth PAN
    Proxies: HTTP, HTTPS, SOCKS

System Software:
  macOS High Sierra 10.13.6 (17G65) 
  Time since boot: About 6 days

Configuration Files:
  File /etc/sudoers size: Found 1584 B but expected 1563 B
  File /etc/sysctl.conf exists but not expected
  /etc/hosts - Count: 12

  System                       Status
  Gatekeeper                   Enabled
  System Integrity Protection  enabled (Custom Configuration)

Unsigned Files:
  Launchd: ~/Library/LaunchAgents/com.qiuyuzhou.shadowsocksX-NG.http.plist
    Executable: ~/Library/Application Support/ShadowsocksX-NG/privoxy --no-daemon privoxy.config
    Details: Exact match found in the whitelist - probably OK
  Launchd: ~/Library/LaunchAgents/com.qiuyuzhou.shadowsocksX-NG.local.plist
    Executable: ~/Library/Application Support/ShadowsocksX-NG/ss-local -c ss-local-config.json -v
    Details: Exact match found in the whitelist - probably OK
  Launchd: /private/var/***/Library/LaunchAgents/com.qiuyuzhou.shadowsocksX-NG.local.plist
    Executable: ~/Library/Application Support/ShadowsocksX-NG/ss-local -c ss-local-config.json -v
    Details: Exact match found in the whitelist - probably OK
  Launchd: /private/var/***/Library/LaunchAgents/com.qiuyuzhou.shadowsocksX-NG.http.plist
    Executable: ~/Library/Application Support/ShadowsocksX-NG/privoxy --no-daemon privoxy.config
    Details: Exact match found in the whitelist - probably OK
  Launchd: /Library/LaunchAgents/com.oracle.java.Java-Updater.plist
    Executable: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/Java Updater.app/Contents/MacOS/Java Updater -bgcheck
    Details: Exact match found in the whitelist - probably OK
  Launchd: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/com.oracle.java.Java-Updater.plist
    Executable: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/Java Updater.app/Contents/MacOS/Java Updater -bgcheck
    Details: Exact match found in the whitelist - probably OK
  Launchd: /Library/LaunchAgents/com.micromat.TechToolProAgent.plist
    Executable: /Library/PreferencePanes/TechTool Protection.prefPane/Contents/PlugIns/TechToolProAgent.app/Contents/MacOS/TechToolProAgent
    Details: Exact match found in the whitelist - probably OK
  Launchd: /Library/LaunchDaemons/com.oracle.java.Helper-Tool.plist
    Executable: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/Helper-Tool
    Details: Exact match found in the whitelist - probably OK
  Launchd: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/com.oracle.java.Helper-Tool.plist
    Executable: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/Helper-Tool
    Details: Exact match found in the whitelist - probably OK
  Launchd: /Library/LaunchDaemons/com.micromat.TechToolProDaemon.plist
    Executable: /Library/PreferencePanes/TechTool Protection.prefPane/Contents/PlugIns/TechToolProDaemon.app/Contents/MacOS/TechToolProDaemon
    Details: Exact match found in the whitelist - probably OK

Kernel Extensions:
    intelhaxm.kext (7.3.0 - SDK 10.9)
    LuLu.kext (1.1.2 - SDK 10.14)
    ufsd_NTFS.kext (15.4.19 - SDK 10.10)

    ssuddrv.kext (1.4.32 - SDK 10.6)
    SamsungPortableSSDDriver.kext (1.5.02 - SDK 10.7)

    ssudmdmcontrol.kext (1.4.32 - SDK 10.6)
    ssudmdmdata.kext (1.4.32 - SDK 10.6)
    ssudmtp.kext (1.4.32 - SDK 10.5)
    ssudserial.kext (1.4.32 - SDK 10.6)

System Launch Agents:
  [Not Loaded]  9 Apple tasks
  [Loaded]      164 Apple tasks
  [Running]     75 Apple tasks
  [Killed]      43 Apple tasks
  [Other]       3 Apple tasks

System Launch Daemons:
  [Not Loaded]  36 Apple tasks
  [Loaded]      155 Apple tasks
  [Running]     105 Apple tasks
  [Killed]      39 Apple tasks
  [Other]       One Apple task

Launch Agents:
  [Loaded]     com.oracle.java.Java-Updater.plist (? 732efa87  - installed 2019-06-25)
  [Other]      com.adobe.AdobeCreativeCloud.plist (Adobe Systems, Inc. - installed 2019-06-18)
  [Not Loaded] com.adobe.GC.AGM.plist (Adobe Systems, Inc. - installed 2019-06-20)
  [Other]      com.google.keystone.agent.plist (Google, Inc. - installed 2019-06-04)
  [Not Loaded] com.adobe.AAM.Updater-1.0.plist (Adobe Systems, Inc. - installed 2019-06-25)
  [Running]    com.micromat.TechToolProAgent.plist (? c83170ec  - installed 2019-06-24)
  [Not Loaded] com.adobe.GC.Invoker-1.0.plist (Adobe Systems, Inc. - installed 2019-06-20)

Launch Daemons:
  [Loaded]     com.sweetpproductions.WiFiSpoofHelperTool.plist (SweetP Productions, Inc. - installed 2019-06-04)
  [Loaded]     com.adobe.ARMDC.Communicator.plist (Adobe Systems, Inc. - installed 2019-06-18)
  [Loaded]     com.google.keystone.daemon.plist (Google, Inc. - installed 2019-06-04)
  [Running]    com.cleverfiles.cfbackd.plist (Justin Johnson - installed 2019-06-08)
  [Loaded]     com.apple.bluetooth.PacketLoggerHelper.plist (Apple - installed 2019-05-13)
  [Running]    com.micromat.TechToolProDaemon.plist (? c4e58e15  - installed 2019-06-24)
  [Loaded]     com.oracle.java.Helper-Tool.plist (? e3fefdd2  - installed 2019-06-25)
  [Loaded]     com.macpaw.CleanMyMac3.Agent.plist (MacPaw Inc. - installed 2018-05-26)
  [Loaded]     com.adobe.ARMDC.SMJobBlessHelper.plist (Adobe Systems, Inc. - installed 2019-06-18)

User Launch Agents:
  [Running]    com.qiuyuzhou.shadowsocksX-NG.local.plist (? 0  - installed 2019-07-10)
  [Not Loaded] com.adobe.GC.Invoker-1.0.plist (Adobe Systems, Inc. - installed 2019-06-20)
  [Loaded]     com.macpaw.CleanMyMac3.Scheduler.plist (MacPaw Inc. - installed 2018-10-19)
  [Running]    com.qiuyuzhou.shadowsocksX-NG.http.plist (? 0  - installed 2019-07-10)

User Login Items:
  ShadowsocksX-NG-R8.app (? - installed 2018-10-08)
  CleanMyMac 3 Menu.app (? - installed 2017-12-19)
     (/Applications/CleanMyMac 3.app/Contents/MacOS/CleanMyMac 3 Menu.app)
  Flux.app (Michael Herf - installed 2018-01-09)
  SmartDaemon.app (Justin Johnson - installed 2019-06-08)
     (/Library/Application Support/CleverFiles/SmartDaemon.app)
  EOS Utility.app (Canon Inc. - installed 2019-01-09)
     (/Applications/Canon Utilities/EOS Utility/EOS Utility.app)
  Image Transfer Utility 2.app (Canon Inc. - installed 2019-07-08)
     (/Applications/Canon Utilities/ImageTransferUtility2/Image Transfer Utility 2.app)
  ShadowsocksX-NG-R8 (? - installed 2018-10-08)
  Flux (Michael Herf - installed 2018-01-09)
  SmartDaemon (Justin Johnson - installed 2019-06-08)
  CleanMyMac 3 Menu (MacPaw Inc. - installed 2017-12-19)
     (/Applications/CleanMyMac 3.app/Contents/MacOS/CleanMyMac 3 Menu.app/Contents/MacOS/CleanMyMac 3 Menu)

Internet Plug-ins:
  AdobeAAMDetect: (installed 2019-06-18)
  FlashPlayer-10.6: (installed 2019-05-15)
  QuickTime Plugin: 7.7.3 (installed 2018-07-04)
  AdobePDFViewerNPAPI: 17.012.20098 (installed 2019-06-25)
  AdobePDFViewer: 19.012.20034 (installed 2019-06-25)
  Flash Player: (installed 2019-05-15)
  Scorch:  (installed 2018-10-25)
  PepperFlashPlayer: (installed 2019-05-18)
  JavaAppletPlugin: Java 8 Update 211 build 12 (installed 2019-06-25)

Safari Extensions:
  Free Download Manager.safariextz - FreeDownloadManager.org - http://freedownloadmanager.org (installed 2018-09-28)

3rd Party Preference Panes:
  Flash Player (installed 2019-04-30)
  FUSE (installed 2018-12-18)
  Java (installed 2019-06-25)
  NTFS (installed 2018-10-02)
  Perian (installed 2013-12-11)
  TechTool Protection (installed 2019-06-24)
  Toolkit (installed 2019-03-15)

Time Machine:
  Skip System Files: No
  Mobile backups: 
  Auto backup: Yes
  Volumes being backed up: 
    M***************a: Disk size: 499.96 GB - Disk used: 477.27 GB 
    J**********p [Local] (Last used)
      Total size: 5.00 TB
      Total number of backups: 14
      Oldest backup: 2019-02-10 12:14:49
      Last backup: 2019-02-19 20:52:43

  System Load: 5.91 (1 min ago) 4.52 (5 min ago) 3.94 (15 min ago)
  Nominal I/O speed: 4.98 MB/s
  File system: 38.13 seconds
  Write speed: 1159 MB/s
  Read speed: 2986 MB/s

Top Processes by CPU:
  Process (count)             Source               CPU  Location
  Google Chrome Helper (172)  Google, Inc.     89.89 %  
  Google Chrome               Google, Inc.     43.62 %  
  kernel_task                 Apple            23.65 %  
  fdm                         SoftDeluxe, Inc  22.64 %  
  WindowServer                Apple            15.62 %  

Top Processes by Memory:
  Process (count)             Source             RAM usage  Location
  Google Chrome Helper (172)  Google, Inc.         6.29 GB  
  kernel_task                 Apple                2.26 GB  
  Google Chrome               Google, Inc.          815 MB  
  fdm                         SoftDeluxe, Inc       573 MB  
  Finder                      Apple                 406 MB  

Top Processes by Network Use:
  Process                   Source             Input  Output  Location
  os-book.com               ?                 198 MB   14 KB  wget -r --xattr -c -N -kK -p --follow-ftp http:
  fdm                       SoftDeluxe, Inc    74 MB    7 MB  
  ss-local                  ?                   9 MB  805 KB  ~/Library/Application Support/ShadowsocksX-NG
  mDNSResponder             Apple            1011 KB  846 KB  
  EmbeddedOSInstallService  Apple             149 KB  210 KB  

Virtual Memory Information:
  Available RAM    1.61 GB
  Free RAM           69 MB
  Used RAM        14.39 GB
  Cached files     1.54 GB
  Swap Used       14.72 GB

Software Installs (past 30 days):
  Name                             Version       Install Date
  Adobe Acrobat DC (19.012.20034)  19.012.20034  2019-06-25
  Java 8 Update 211                1.0           2019-06-25
  Air Explorer                     1.6.1         2019-07-08

Diagnostics Information (past 7 days):
  2019-07-10 17:33:02 Xcode.app Crash
    dyld: launch, loading dependent libraries, ignoring DYLD_* env vars

  2019-07-10 11:47:41 AppDelete.app Crash
    Crashing on exception: *** -[__NSArrayM objectAtIndex:]: index 0 beyond bounds for empty array

  2019-07-10 11:29:07 ifuse Crash
    dyld: launch, loading dependent libraries

  2019-07-09 13:43:52 quicklookd.app CPU

  2019-07-08 13:12:05 com.apple.WebKit.Plugin.64 Crash

  2019-07-08 10:41:24 UniversalInstaller.app Crash

  2019-07-08 10:36:24 coreaudiod Crash

  2019-07-06 11:46:07 KeyRecoveryAssistant.app Crash
    dyld: launch, loading dependent libraries

  2019-07-04 13:19:34 UpdaterStartupUtility Crash
    /Applications/Utilities/Adobe Application Manager/*/UpdaterStartupUtility
    abort() called
    *** error for object 0x7fb546711f98: incorrect checksum for freed object - object was probably modified after being freed.

  2019-07-04 13:13:09 Last Shutdown Cause: 3 - Hard shutdown

  2019-07-04 13:00:52 mdworker CPU

  2019-07-03 20:54:26 Kernel Panic
    3rd party kernel extensions: 
    com.objective-see.lulu  1.1.2
    com.devguru.driver.SamsungMTP   1.4.32
    com.samsung.portablessd.driver  1.5.02
    com.devguru.driver.SamsungACMData   1.4.32

End of report
  • I be worried about this drive. Please get a backup. Try a different port and a different cable. If no go, consider a new enclosure. If no go, a new drive. Commented Jun 29, 2019 at 18:35
  • @historystamp The SMART status is good. Furthermore, this drive is new and I haven't dropped it once.
    – Joy Jin
    Commented Jul 9, 2019 at 4:10
  • It's your drive and your data. What you report isn't normal. Something is amiss. Try a different cable and different port. Try a different computer if you can. Have what ever data on the drive backed up. Drive failure history: prosofteng.com/blog/how-long-do-hard-drives-last Commented Jul 9, 2019 at 18:59
  • Get rid of: com.macpaw.CleanMyMac3.Agent.plist (MacPaw Inc. - installed 2018-05-26) Many regard this as pure malware. Commented Jul 10, 2019 at 16:32
  • what is this app about? Notice the different installation dates. com.qiuyuzhou.shadowsocksX-NG.local.plist (? 0 - installed 2019-07-10) [Running] com.qiuyuzhou.shadowsocksX-NG.http.plist (? 0 - installed 2019-07-10) Commented Jul 10, 2019 at 16:48

3 Answers 3


diskutil eject does not accept force (see man diskutil) and if the disk is in use may fail with "Volume timed out while waiting to eject"

 eject device
            Eject a disk.  Media will become offline for the purposes of
            being a data store for file systems or being a member of con-
            structs such as software RAID or direct data.  Additionally,
            removable media will become eligible for safe manual removal;
            automatically-removable media will begin its physical (motor-
            ized) eject sequence.

If you want to eject the disk (which will mean it is not available to be mounted until you reboot or unplug/reinsert it) then it would be you should unmount any filesystems first for example using diskutil unmountDisk

 unmountDisk | umountDisk [force] device
            Unmount an entire disk (all volumes).  Force will force-
            unmount the volumes (less kind to any open files; see also umount (8)).

Assuming you want disk2 this would mean running in terminal either

diskutil unmountDisk /dev/disk2

or (if you want to force it with associated risks)

diskutil unmountDisk force /dev/disk2

followed by

diskutil eject /dev/disk2

If you click on the 'eject' button in Finder and the drive does not respond, you should get a pop-up message with the possibility to force the ejection of the drive.

  • Finder (and other applications which access the drive) would actually freeze due to I/O delay/error. Furthermore, unmounting the drive is not the same thing as ejecting the drive. If you eject the drive, you won't see it listed in "diskutil list"
    – Joy Jin
    Commented Jul 9, 2019 at 4:09

my system will freeze if I don't pull it out.
Something is amiss with your system. This isn't normal behavior. Let's look for the root cause of why this is happening.

  • What happens if you reboot?
  • You should try a reset of your i/o system. https://support.apple.com/en-us/HT204063
  • Try a safe boot. Should you drive work fine in safe mode, it means some software is interfering with the working of the drive.

    Shutdown your machine. Hold down the shift key. Poweron. The boot up will take longer than normal because the filesystem on the startup drive is being checked and repaired as needed. All about safe mode including what features and apps safe boot leaves out. Safe boot uses a software driver instead of using your machines video hardware. http://support.apple.com/kb/ht1455

  • If you want us to look for problamatic software that's on your machine, please post an etrecheck report. Etrecheck will analyze your machine and software and report back what experienced users have found to be useful information when diagnosing problems. Post results here so others can view. The proprietary stuff gets filtered.

Install and run

  • Download etrecheck. Goto the http://www.etrecheck.com/ download page. The download link is at the bottom of the screen
  • Install etrecheck. Goto your download folder. Double click on EtreCheckPro.zip
  • drag the app to the application folder if you wish.
  • Double click on etrecheck to run. The first five runs are free.

    An alternative explanation how to install, run and report output for the EtreCheck Application. You may find Old Toad's write up helpful. https://discussions.apple.com/docs/DOC-250000211

  • 1
    My system does not freeze. It's the application which access the drive that freeze, for example, Finder or Dock. Because the main GUI experience of macOS is based on Dock and Finder, it would feel like the system is frozen (you can still move the mouse), and once you get rid of the frozen device these applications became normal.
    – Joy Jin
    Commented Jul 10, 2019 at 10:21
  • I've tried NVRAM and SMC resets. They changed nothing.
    – Joy Jin
    Commented Jul 10, 2019 at 10:22
  • Safe boot seems to not work for me. I have tried to disable firmware password, but it seems like I can't get in to safe mode. I will try again when I get a chance.
    – Joy Jin
    Commented Jul 10, 2019 at 10:23
  • I had run Apple Hardware Test and that shows no hardware problem.
    – Joy Jin
    Commented Jul 10, 2019 at 10:24
  • I would run fsck routinely and I don't see any problem so far for both my internal SSD (apfs) and the Seagate HDD (hfs+ journaled) except for "overallocation" problems on apfs that wouldn't be repaired.
    – Joy Jin
    Commented Jul 10, 2019 at 10:26

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