I ran into an interesting macOS error while working with a customer. I didn't find a lot of good search results addressing the issue, so I decided to write up a post about it myself.
The error was as the screenshot above shows; trying to open a dmg (disk image), macOS showed the error 'no mountable file systems'. If you see the 'no mountable file systems error' while opening a dmg, here's what you should try:
- In most cases, the downloaded dmg file is actually corrupt or had an error downloading. If possible, try downloading the dmg again, turning off any download assistant plug-ins you may have. You can try downloading the file in a different browser as well. Or if you don't need to be logged in to the site to download the file and you want to be fancy, you can try
curl -O url
in Terminal to download the file. (There's an example of that in my screenshot below.) - Reboot your Mac if you haven't already tried that. Apparently there is an issue sometimes after opening too many dmg files, that is fixed with a reboot.
- Try mounting the DMG on the command line in Terminal. We will at least get some sort of useful error message to go on if it still fails:
- Open Terminal: In Spotlight, the search magnifying glass at the upper right corner of your screen, search for Terminal, and press enter to open the Terminal app.
- Type
hdiutil attach -verbose
into the terminal. Add a space at the end, but don't press enter yet. - Drag the dmg file from your Finder window onto the Terminal window and let go. You are a muenster mac os. This will fill in the location of the dmg file into your Terminal window.
- Press enter.
- macOS Sierra (10.12) and earlier is not able to mount the new Apple File System (APFS). So if you're on macOS Sierra (10.12) or earlier and you ran hdiutil and see references to
Apple_APFS
or error112
, the issue is likely legitimate incompatibility, and this disk image won't open on this Mac without an update to the operating system.Here's an example of the end ofhdiutil attach -verbose
output that shows an APFS error due to an older version of macOS: - Think about if you have any kind of security policies on this machine to prevent writing to external drives (thumb drives, optical drives, etc). I haven't seen this one in action, but I read about this being a possibility while researching the issue.
- Another suggestion added by a reader (thank you, Markus!) is that filesystem errors on your main Mac drive could be the cause of the disk image mounting errors. Here are instructions from Apple for scanning and repairing errors using Disk Utility. Note that in order to scan and repair errors on your main Macintosh HD drive, you'll need to reboot your Mac into recovery mode. You'll want to choose Disk Utility in the utilities listed in the recovery mode menu.
- A new discovery from a reader (thank you, Colby!) is that APFS DMGs won't mount if you're booted in macOS booted in Safe Mode. (Who knew!?!) If you're not sure if you're in safe mode, select the Apple menu > About This Mac > System Report button, then select the 'Software' heading from the left column. To exit safe mode, restart your Mac, without holding Shift during startup. Or, if you previously set your Mac to always boot into safe mode using
nvram
, turn off safe mode and have your Mac boot normally on the terminal:- Open Terminal: In Spotlight, the search magnifying glass at the upper right corner of your screen, search for Terminal, and press enter to open the Terminal app.
- Type/paste
sudo nvram boot-args='
and press enter. - Restart your Mac.
- Another new discovery (thank you, Iris!) is that if you have APFS by Paragon software installed on a Mac that can read APFS itself, it can interfere with opening the DMG. So if you used APFS by Paragon and then updated your Mac, you may need to uninstall it.
Apr 07, 2020 On my iMac there is a file in the Applications folder labeled 'macOS High Sierra.appdownload'. There's no 'Install macOS High Sierra.app' file, though the download took 98 minutes. A search on my computer for the 'Install' app brings up nothing. It is excruciatingly slow and has really no features in the app that aren’t features within the watch settings. The funny part about it is, I had to reinstall Wear OS because I thought maybe that would help. But I noticed that once I had uninstalled the app, al of a sudden the watch sped up, and was functioning much more quickly. Searching for old and unused files on your Mac helps reduce clutter and free up disk space (free for premium users, available to other Mac OS Yosemite or above users via in-app purchase) Disk Usage Tool Track down which files and folders consume the most space in your home folder, your Mac's internal or any removable disk. For Mac OS X 10.11 or later. Note: Installing Google Chrome will add the Google repository so your system will automatically keep Google Chrome up to date. If you don’t want Google's.
One footnote for people having issues opening ISO files. Another new discovery is that 'hybrid' ISO files (think Linux installers) don't open correctly automatically and need to be manually attached and mounted (this is NOT advice for normal .dmg files.) Credit to the this superuser.com discussion and this Apple forum discussion for solutions.
Summary: This a full guide to external SSD not recognized on Mac issue, which includes both reasons and solutions to this issue, as well as how to recover lost data when external SSD is not showing up on Mac.
You can't access a Sandisk, Crucial, or Samsung T3 when the external SSD is not recognized or detected by Mac, whether the external SSD was working for a long time or it's a new SSD you bought recently.
However, hard drives not working or showing up issue is so prone to happen even when you unplug the external SSD from the Mac and later on plug in the SSD again. It's definitely frustrating, especially when you have important files stored on it.
![Up mt. no mac os pro Up mt. no mac os pro](https://www.howtoisolve.com/wp-content/uploads/2019/06/Add-iOS-device-iPhone-and-iPad-under-the-locations-in-Sidebar-on-Mac.png)
How can you fix the unrecognized external SSD and access your files stored on it? You'll find the solutions to fix the unrecognized or undetected external SSD in this post.
- 1. Check the connections
- 2. Reboot your Mac computer
- 3. Check the unrecognized external SSD in Disk Utility
- 4. Repair the unrecognized external SSD with First Aid
- 5. Reformat the unrecognized external SSD without data loss
- 6. Send the external SSD to a local technician
How to avoid data loss when external SSD not recognized on Mac?
As you can't access the important files on your external SSD that not showing up, data loss may happen. To avoid such a frustrating thing occurs, you'd better recover data from your unrecognized external SSD.
Besides, formatting your external SSD is one of the solutions (always the most efficient way) to fix this issue, so, data recovery of your external SSD is very necessary.
If you have a backup of your external SSD, you can skip this data recovery work. If not, you need to use some data recovery software.
iBoysoft Data Recovery Software for Mac is highly recommended here to recover lost data from unrecognized external SSD. It's a free and secure data recovery tool, which can recover lost data from corrupted, formatted, unreadable, and unmountable SSD. This software works on macOS Big Sur 11/10.15/10.14/10.13/10.12 and Mac OS X 10.11/10.10/10.9/10.8/10.7.
Moreover, iBoysoft Data Recovery for Mac supports main storage devices including hard drives, external hard drives, USB flash drives, SD cards, memory cards, etc. and multiple file formats such as documents, audios, pictures, videos, emails, etc. Rythmic mac os.
Tutorial to recover lost data from unrecognized SSD on Mac with iBoysoft Data Recovery for Mac
- 1. Launch iBoysoft Data Recovery for Mac.
- 2. Select the unrecognized external SSD and click 'Next' to scan lost files on the drive.
- 3. Preview the scanning results, choose files we need, and click 'Recover' to get lost files back from the unrecognized external SSD.
- 4. Have a check to ensure we have recovered all lost files.
How to fix external SSD not recognized on Mac?
Solution 1: Check whether the external SSD is properly plugged in
Since all SSDs use SATA interface, so when an external SSD is not recognized by Mac, the first and foremost solution is to check whether the external SSD is properly plugged in. So simply do these checks:
- Check if the cable is working by connecting the external SSD with a different cable.
- Check whether your SSD is using SATA Ⅰ, Ⅱ, or Ⅲ so that your adapter/dock/case is compatible with your external SSD.
- Try a different SATA to USB adapter and make sure it works by plugging in a different drive.
- Try to connect the external SSD directly to your Mac if it's a type C drive, rather than accessing it via a USB-C adapter.
![Up Mt. No Mac OS Up Mt. No Mac OS](https://imgix-blog.setapp.com/turn-off-voiceover-shortcut.png?auto=format&ixlib=php-3.3.0&q=75)
Up Mt. No Mac Os 11
If the unrecognized external SSD is a Samsung T5/T3 SSD, and you got the 'System Extension Blocked' and 'No Samsung Portable SSD is connected' messages when executing Samsung Portable SSD Software, simply go to System Preferences > Security & Privacy > choose Allow button next to the message: System software from developer 'Samsung Electronics' was blocked from loading.
Solution 2: Reboot your Mac computer
Sometimes, Mac externalSSD not mounting issue is caused by the system issues. But you easily fix them by restarting. The restarting process will refresh your macOS's memory and starts it up fresh, which works efficiently especially when the USB port is busy. Simply choose the Apple menu and click Restart.
If you are interested in, you can learn what happened inside when Mac doesn't recognize an external drive with details.
Solution 3: Find the unrecognized external SSD in Disk Utility
When an external SSD is not showing up on Mac, the most necessary step is to check whether the external SSD can be found in Disk Utility. If the external SSD can be found in Disk Utility, you make sure that the drive doesn't have any hardware problems. But if you can't find it listed in Disk Utility, the external SSD might be physically damaged.
So simply Go > Disk Utility > View > Show All Devices to check the external SSD.
- If your external SSD is using Windows NTFS format, macOS won't mount the drive in writable mode. To write to an NTFS drive, you need to download a free NTFS for Mac driver.
- If you have used this external SSD on other computers for some time and now it is unrecognized by macOS, the file system of the SSD is either unsupportable or corrupted, you need to recover lost data from this external SSD and reformat the drive.
- If you newly bought this SSD and it is not initialized, you can't see the partitions of the external SSD in Disk Utility but receive an error message 'the disk you inserted was not readable by this computer'. In this case, you need to make sure you don't have any data on this drive and then initialize it in Disk Utility by erasing.
Solution 4: Repair the unrecognized external SSD with First Aid
If your external SSD shows up in Disk Utility but not mounted, you can right-click the drive and select Mount menu and then the SSD will show up on Mac. If the Mount button is grayed out or you fail to mount the external SSD, try running First Aid to verify and repair disk errors.
Up Mt. No Mac Os X
- 1. Launch Disk Utility.
- 2. Choose the grayed out external SSD from the left sidebar.
- 3. Select the 'First Aid' tab on the top.
Solution 5: Reformat the unrecognized external SSD without data loss
If all solutions above don't work, the external SSD might be corrupted and you need to reformat it. Whether the external SSD is not recognized due to logical disk errors or hardware problems, the most important is your files on the drive.
The thing is, reformatting will cause data loss. So, to prevent data loss, you need to get your files off this external SSD first if you forget to back up. iBoysoft Data Recovery for Mac will help you get your data back within a few clicks.
After your important data is recovered, you can go ahead to fix this issue by reformatting without data loss.
Tutorial to reformat the unrecognized external SSD
This guide to reformat external SSD will remove all data on the external SSD, please make sure you have recovered all useful files with iBoysoft Data Recovery.
- 1. Launch Disk Utility.
- 2. Select the external SSD on the left part of the window.
- 3. Click 'Erase' on the top of the Disk Utility window.
- 4. Complete related information (name, format, scheme), then click Erase.
Solution 6: Send the external SSD to a local technician for help
If unfortunately, the external SSD can't show up in Disk Utility or the solutions above failed to fix external SSD not recognized issue, the drive might have some hardware problems. You need to contact the manufacturer for technical support or product replacement.
• Fix SSD not showing up in Windows 10/8/7
Why is external SSD not recognized on Mac?
Various reasons are leading to external SSD not showing up issue on Mac. Here we conclude four main causes as below:
1. The SATA to USB 3.0 adapter/Dock is malfunctioned.
Usually, you need to buy an additional dock, disk case, or SATA adapter to access an SSD drive. During this process, if the externally connected SSD is not recognized by your Mac, it's likely that the adapter is not compatible with the disk's SATA interface, or the dock/drive caddy is faulty.
2. The external SSD is new and uninitialized.
This happens when users externally connect the SSD to backup or transfer files on the internal hard drive. But many newly bought SSDs are not initialized with a file system, which means there is no entrance for macOS to recognize and communicate with this SSD, and for sure, the external SSD won't show up.
3. The external SSD has a file system that can't be recognized by Mac.
Possibly, the SSD that you try to access is formatted with a file system. However, it's not a file system that your Mac can recognize. For example, it is formatted with a Linux file system. In this case, your macOS can't recognize the external SSD surely.
Up Mt. No Mac Os 11
4. New software or firmware needs to be updated.
This happens frequently for Samsung portable SSD T5/T3, because you need to install Samsung portable SSD Software to unlock disk's password and update certain firmware for this SSD. And if the necessary software and extension are not downloaded, you may receive 'No Samsung portable SSD is connected' from its software.
5. The external SSD is not set to show up on Mac.
Sometimes, your external SSD actually is recognized by the Mac, but some setups stop the SSD from showing up in the Finder, on the desktop, or even in the Disk Utility. Focus your locus mac os.
6. The external SSD is corrupted.
Another possible cause is that you have unsafely ejected your SSD, which makes the external drive corrupted after some core data like partition table or file system is damaged. Also, you need to be clear that the life span of an SSD is limited depending on how frequently you use it.
7. Other Hardware problems.
Some SSD support pages you may need:
Up Mt. No Mac Os Pro
- Samsung: https://www.samsung.com/semiconductor/minisite/ssd/support/warranty/
- Crucial: https://uk.crucial.com/gbr/en/support?cm_re=top-nav-v2-_-flyout-support-_-support-home
- Intel:https://supporttickets.intel.com/?lang=en-US
- WD: https://www.westerndigital.com/support
- Kingston: https://www.kingston.com/en/company/warranty
- Toshiba: https://www.toshiba-memory.com/warranty/