macOS Sierra External Drive Mounting Issues

Starting with Sierra, macOS doesn't auto mount network servers at boot because it is a security risk. Therefore, it asks you for the password every time. If this sounds like your problem, see the fix below.

Resolve Auto-Connect Issues on Network Drives

To stop macOS Sierra from ignoring the password in the keychain, open Terminal and execute the following text:

“sudo defaults write /Library/Preferences/com.apple.NetworkAuthorization AllowUnknownServers -bool YES”

See this article for more details:

https://support.apple.com/en-us/HT207112

EtreCheck version: 3.1.5 (343)

Report generated 2017-04-13 19:19:05

Download EtreCheck from https://etrecheck.com

Runtime 2:30

Performance: Excellent

Click the [Support] links for help with non-Apple products.

Click the [Details] links for more information about that line.

Problem: Other problem

Description:

External hard disks don’t mount if they are turned on before the mac is on.

Hardware Information:ⓘ

iMac (27-inch, Late 2013)

[Technical Specifications] - [User Guide] - [Warranty & Service]

iMac - model: iMac14,2

1 3,2 GHz Intel Core i5 (i5-4570) CPU: 4-core

32 GB RAM Upgradeable - [Instructions]

BANK 0/DIMM0

8 GB DDR3 1600 MHz ok

BANK 1/DIMM0

8 GB DDR3 1600 MHz ok

BANK 0/DIMM1

8 GB DDR3 1600 MHz ok

BANK 1/DIMM1

8 GB DDR3 1600 MHz ok

Bluetooth: Good - Handoff/Airdrop2 supported

Wireless: en1: 802.11 a/b/g/n/ac

Video Information:ⓘ

NVIDIA GeForce GT 755M - VRAM: 1024 MB

iMac 2560 x 1440

PL2779Q 2560 x 1440 @ 59 Hz

System Software:ⓘ

macOS Sierra 10.12.4 (16E195) - Time since boot: about 5 hours

Disk Information:ⓘ

APPLE SSD SD0128F disk0 : (121,33 GB) (Solid State - TRIM: Yes)

[Show SMART report]

EFI (disk0s1) <not mounted> : 210 MB

Boot OS X (disk0s3) <not mounted> : 134 MB

Macintosh HD (disk2) / [Startup]: 1.11 TB (846.50 GB free)

Core Storage: disk0s2 120.99 GB Online

Core Storage: disk1s2 999.35 GB Online

APPLE HDD ST1000DM003 disk1 : (1 TB) (Rotational)

[Show SMART report]

EFI (disk1s1) <not mounted> : 210 MB

Recovery HD (disk1s3) <not mounted> [Recovery]: 650 MB

Macintosh HD (disk2) / [Startup]: 1.11 TB (846.50 GB free)

Core Storage: disk0s2 120.99 GB Online

Core Storage: disk1s2 999.35 GB Online

ST3000DM001-1CH166 disk3 : (3 TB) (Rotational)

[Show SMART report]

EFI (disk3s1) <not mounted> : 210 MB

Projects HD (disk3s2) /Volumes/Projects HD : 3.00 TB (2.25 TB free)

USB Information:ⓘ

Seagate Backup+ Desk

Apple Inc. BRCM20702 Hub

Apple Inc. Bluetooth USB Host Controller

Apple Inc. FaceTime HD Camera (Built-in)

Apple, Inc. Keyboard Hub

Fujitsu Takamisawa Component Apple Optical USB Mouse

Apple Inc. Apple Keyboard

Thunderbolt Information:ⓘ

Apple Inc. thunderbolt_bus

LaCie d2

Gatekeeper:ⓘ

Mac App Store and identified developers

Kernel Extensions:ⓘ

/Library/Application Support/Roxio

[not loaded] com.roxio.TDIXController (1.2 - 2014-07-21) [Support]

/System/Library/Extensions

[not loaded] com.rogueamoeba.InstantOn (6.0.1 - SDK 10.6 - 2017-04-07) [Support]

[not loaded] com.tomtom.driver.UsbEthernetGadget (1.0.0d1 - 2017-04-07) [Support]

/System/Library/Extensions/InstantOn.kext/Contents/PlugIns

[not loaded] com.rogueamoeba.InstantOnCore (6.0.1 - SDK 10.6 - 2012-07-31) [Support]

System Launch Agents:ⓘ

[not loaded] 7 Apple tasks

[loaded] 171 Apple tasks

[running] 104 Apple tasks

System Launch Daemons:ⓘ

[not loaded] 40 Apple tasks

[loaded] 173 Apple tasks

[running] 105 Apple tasks

Launch Agents:ⓘ

[not loaded] com.adobe.AAM.Updater-1.0.plist (2013-02-28) [Support]

[failed] com.google.keystone.agent.plist (2016-03-30) [Support]

[loaded] com.oracle.java.Java-Updater.plist (2016-04-28) [Support]

[loaded] org.macosforge.xquartz.startx.plist (2016-05-05) [Support]

Launch Daemons:ⓘ

[loaded] com.adobe.SwitchBoard.plist (2013-02-28) [Support]

[loaded] com.adobe.fpsaud.plist (2017-03-24) [Support]

[loaded] com.adobe.versioncueCS3.plist (2008-10-20) [Support]

[running] com.backblaze.bzserv.plist (2017-04-13) [Support]

[running] com.cleverfiles.cfbackd.plist (2015-06-25) [Support]

[loaded] com.google.keystone.daemon.plist (2016-03-30) [Support]

[loaded] com.malwarebytes.HelperTool.plist (2017-01-16) [Support]

[loaded] com.microsoft.office.licensing.helper.plist (2010-11-29) [Support]

[loaded] com.oracle.java.Helper-Tool.plist (2016-04-01) [Support]

[loaded] org.macosforge.xquartz.privileged_startx.plist (2016-05-05) [Support]

User Launch Agents:ⓘ

[not loaded] com.adobe.AAM.Updater-1.0.plist (2012-08-30) [Support]

[not loaded] com.adobe.ARM.[...].plist (2014-09-29) [Support]

[running] com.backblaze.bzbmenu.plist (2017-04-13) [Support]

[loaded] com.dropbox.DropboxMacUpdate.agent.plist (2017-04-10) [Support]

[not loaded] com.google.keystone.agent.plist (2012-07-21) [Support]

[running] com.spotify.webhelper.plist (2017-04-03) [Support]

User Login Items:ⓘ

Dropbox Application

(/Applications/Dropbox.app)

Google Drive Application

(/Applications/Google Drive.app)

TomTomHOMERunner Application

(~/Library/Application Support/TomTom HOME/TomTomHOMERunner.app)

Adobe InDesign CS6 Application

(/Applications/Adobe InDesign CS6/Adobe InDesign CS6.app)

Launch Nikon Message Center 2 Application

(/Applications/Nikon Software/Nikon Message Center 2/Nikon Message Center 2.app/Contents/SharedSupport/Launch Nikon Message Center 2.app)

Internet Plug-ins:ⓘ

DirectorShockwave: 11.0.0r465 (2008-08-01) [Support]

OfficeLiveBrowserPlugin: 12.2.0 (2009-08-19) [Support]

Flip4Mac WMV Plugin: 2.1.0.33 (2006-07-13) [Support]

Musicnotes: 1.16.13 (2008-09-07) [Support]

VLC Plugin: 1.0.5 (2012-06-05) [Support]

AdobePDFViewerNPAPI: 10.1.12 (2014-09-29) [Support]

FlashPlayer-10.6: 25.0.0.148 - SDK 10.9 (2017-04-11) [Support]

Silverlight: 5.1.41212.0 - SDK 10.6 (2016-01-23) [Support]

QuickTime Plugin: 7.7.3 (2017-04-07)

Flash Player: 25.0.0.148 - SDK 10.9 (2017-04-11) [Support]

iPhotoPhotocast: 7.0 (2008-12-05)

PepperFlashPlayer: 25.0.0.148 - SDK 10.9 (2017-04-11) [Support]

AdobePDFViewer: 8.1.7 (2009-10-23) [Support]

GarminGpsControl: 4.0.3.0 Release - SDK 10.6 (2012-07-16) [Support]

SharePointBrowserPlugin: 14.7.1 - SDK 10.6 (2017-01-20) [Support]

JavaAppletPlugin: Java 8 Update 91 build 14 (2016-04-28) Check version

User internet Plug-ins:ⓘ

Move_Media_Player: npmnqmp 071101000050 (2008-09-12) [Support]

Safari Extensions:ⓘ

Adblock Plus - Eyeo GmbH - https://adblockplus.org/ (2016-12-21)

AdBlock - BetaFish, Inc. - https://getadblock.com (2016-05-16)

Translate - SideTree.com - Apps for Mac and Web - http://SideTree.com/extensions.html#Translate (2015-11-22)

3rd Party Preference Panes:ⓘ

Adobe Version Cue CS3 (2008-12-05) [Support]

Backblaze Backup (2017-04-13) [Support]

Flash Player (2017-03-24) [Support]

Flip4Mac WMV (2006-07-13) [Support]

FUSE for OS X (OSXFUSE) (2013-06-15) [Support]

Java (2016-04-28) [Support]

Time Machine:ⓘ

Skip System Files: NO

Mobile backups: OFF

Auto backup: YES

Volumes being backed up:

Projects HD: Disk size: 3.00 TB Disk used: 747.11 GB

Macintosh HD: Disk size: 1.11 TB Disk used: 267.65 GB

Destinations:

backup Projects HD [Local]

Total size: 4.00 TB

Total number of backups: 162

Oldest backup: 14/03/2014, 16:19

Last backup: 13/04/2017, 18:15

Size of backup disk: Adequate

Backup size 4.00 TB > (Disk used 1.01 TB X 3)

Top Processes by CPU:ⓘ

27% Google Chrome Helper(14)

15% WindowServer

12% Finder

7% Google Chrome

5% kernel_task

Top Processes by Memory:ⓘ

1.86 GB Google Chrome Helper(14)

1.80 GB kernel_task

1.09 GB softwareupdated

885 MB Adobe Photoshop CS6

623 MB mds_stores

Virtual Memory Information:ⓘ

19.19 GB Available RAM

15.25 GB Free RAM

12.81 GB Used RAM

3.93 GB Cached files

0 B Swap Used

Diagnostics Information:ⓘ

Apr 13, 2017, 07:05:14 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-190514_[r edacted].crash

com.google.Keystone.Agent - /Library/Google/*/GoogleSoftwareUpdate.bundle/Contents/Resources/GoogleSoftware UpdateAgent.app/Contents/MacOS/GoogleSoftwareUpdateAgent

Apr 13, 2017, 06:06:30 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-180630_[r edacted].crash

Apr 13, 2017, 05:07:47 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-170747_[r edacted].crash

Apr 13, 2017, 04:09:04 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-160904_[r edacted].crash

Apr 13, 2017, 03:10:23 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-151023_[r edacted].crash

Apr 13, 2017, 02:12:53 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-141253_[r edacted].crash

Apr 13, 2017, 02:11:44 PM ~/Library/Logs/DiagnosticReports/FinderSyncAPIExtension_2017-04-13-141144_[reda cted].crash

com.google.GoogleDrive.FinderSyncAPIExtension - /Applications/Google Drive.app/Contents/PlugIns/FinderSyncAPIExtension.appex/Contents/MacOS/FinderSy ncAPIExtension

Apr 13, 2017, 02:11:40 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-141140_[r edacted].crash

Apr 13, 2017, 02:11:25 PM Self test - passed

Apr 13, 2017, 09:37:15 AM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-093715_[r edacted].crash

Apr 13, 2017, 09:35:03 AM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-093503_[r edacted].crash

Apr 13, 2017, 09:32:11 AM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-093211_[r edacted].crash

Apr 13, 2017, 09:12:12 AM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-091212_[r edacted].crash

Apr 13, 2017, 09:01:32 AM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-13-090132_[r edacted].crash

Apr 12, 2017, 07:28:52 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-12-192852_[r edacted].crash

Apr 12, 2017, 06:30:08 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-12-183008_[r edacted].crash

Apr 12, 2017, 05:31:25 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-12-173125_[r edacted].crash

Apr 12, 2017, 04:32:42 PM ~/Library/Logs/DiagnosticReports/GoogleSoftwareUpdateAgent_2017-04-12-163242_[r edacted].crash

Apr 12, 2017, 11:40:45 AM /Library/Logs/DiagnosticReports/Adobe InDesign CS6_2017-04-12-114045_[redacted].cpu_resource.diag [Details]

/Applications/Adobe InDesign CS6/Adobe InDesign CS6.app/Contents/MacOS/Adobe InDesign CS6

Apr 12, 2017, 08:43:06 AM ~/Library/Logs/DiagnosticReports/FinderSyncAPIExtension_2017-04-12-084306_[reda cted].crash

There appears to be an issue with Apple's USB 3.0 Bus chipset/hardwire/driver. Try using a USB 2.0 cable or connect your USB 3.0 to a 2.0 USB hub and see if that mounts it.

My issue was that Passport X 25BD 2.0/3.0 wouldn't mount. It didn't show in Disk Util or under USB in System Report. It mounted fine on my older Mac with the USB Hi-Speed Bus. I connected it to a USB 4-port 2.0 hub and a USB 2.0 female-male extender, and the reduction from 3.0 to 2.0 fixed the issue. Of course, this was after I formatted the 500 GB Dropbox I had on the drive to see if it was a formatting issue, so thanks for that Apple.

I have the same problem. I have two Lacie d2 Thunderbolt 2 drives connected via Thunderbolt to a late 2015 iMac 5K 27". Under 10.12.4 they don't want to automatically mount to the desktop upon startup, and I have to use Disk Utility to mount them. Any insights or ideas would be welcome--I can't seem to figure out what version of firmware these drives are using or how to update them.

Same problem here. I have everything plugged into one power strip. So I turn on the power strip (which turns on the external drives and the second screen) and then start up the mac. The LaCie d2 (Thunderbolt connection) doesn't mount after startup. I turn off the drive and then turn back on the drive . Not a handy solution.

Neither of my external disks mount if they are running before I start up the mac (Imac 27 inch late 2013 running Sierra 10.12.4). One disk is a LaCie d2 (Thunderbolt connection). The other is a Seagate (usb connection). They mount only if they are powered on after the mac has started up. This is the case since the latest updates, on April 7, 2017: Remote Desktop Client Update 3.9.2 and mac OS Sierra Update 10.12.4. Before these updates, the running disks mounted on startup. Regarding v-22's response, these are just external hard disks, not network servers. They don't require a password. Any ideas?

Yes, I think this is the same thing. There seems to be a bug with the latest update to 10.12.4 - it prevents the mounting of running external hard disks. Even Disk Utility won't mount the disks if the disks were turned on before the mac. The only solution I've found is to turn off and on the disks or to unplug and replug their cables. A pain - and not normal!

Download and run Etrecheck. Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

I don't see any of the usual suspect that might be interfering with the EHDs mounting.

However, you're getting a lot of crashes with the Google software update agent. Personally I'd remove the automatic Google update software and update only when you determine it necessary. That software can be pretty invasive and a resource hog.

I have 10.12.5 Sierra recently upgraded and had the same problem and your suggestion worked to power off the external drive while connected and power on. Just disconnecting and reconnecting did not work. Thanks,Craig

I have a number of external drives attached to a USB hub.

Is the hub a self powered one? If not then the combined drives may be exceeding the current capability of the port and causing the problem.

I posted this a few days ago it might be a similar problem:

https://discussions.apple.com/thread/7918822?answerId=31615700022#31615700022

Same problem, Mac MINI...

I also have a similar problem.

I have a number of external drives attached to a USB hub. Previous to MacOS Sierra they all mounted fine. Now a couple of them seem to only partially mount. I say partially as they don't show up under "Devices" in the Finder but Carbon Copy Cloner recognizes them and does a backup to a drive that is fully mounting. I can find the drives using "Finder > Go > Go to Folder > /Volumes". But accessing them problem drives that way only allow read access. I can also see the drives in Disk Utility as mounted but they no longer show the drive formats as (Journaled), but just Mac OS Extended. My other drives show correctly (Mac OS Extended (Journaled)) on all accounts.

My current short term solution is to go to Disk Utility, unmount the problem drives and then remount them. Then they show in the Finder correctly and are read and write. It's a solution but an added activity in my workflow every day.

MacBook Air (13-inch, Mid 2012)

External Drives Mounting OK:

- LaCie d2 quadra / 2TB (Older drive / two partitions, both mount fine)

- LaCie Rugged FW / 500GB (Older drive)

External Drives Not Mounting Properly:

- Seagate BUP Slim SL / 1TB (Newer drive)

- Hitachi HTS541612J9AT00 /12GB (Older drive that was originally branded Lacie)

Hoping that Apple is working on fix. For what it's worth I've submitted this to Apple here:

https://www.apple.com/feedback/macosx.html

Unfortunately for me, Disk Utility hangs trying to open. I can't even Mount/Unmount using the Terminal commands. This is crazy bad.