My APFS volume will not mount. What can I do?

If your drive is healthy but an APFS volume on it will not mount and does not appear in the Finder, you are most likely dealing with directory damage rather than a hardware failure. The directory is the index macOS uses to find your files. When it is damaged badly enough, macOS refuses to mount the volume at all, even though every one of your files is still sitting on the disk.

This FAQ applies to any APFS volume: internal or external, a single drive or a RAID volume.

If your volume is formatted HFS+ (Mac OS Extended) rather than APFS, the tools and steps are different. See our FAQ: My HFS+ volume will not mount.

Does this match what you are seeing?

• The volume does not appear in the Finder or on the Desktop

• The volume appears in Disk Utility but is greyed out, and the Mount button does nothing

• Clicking Mount in Disk Utility produces a message such as Could not mount “your volume name”, followed by a code such as com.apple.DiskManagement.disenter error 49218, or error -119930868
(Note: Selecting Mount in SoftRAID will result in the “mounting volume” message, until it ultimately fails, SoftRAID is relying on MacOS to mount the volume)

• First Aid fails, or reports that the volume could not be verified or could not be repaired

• fsck reports errors such as the container superblock is invalid, or the object map is invalid

If so, you are in the right place.

Important: do not erase

Do not erase, reformat, initialize, or repartition the volume, and do not delete and recreate it. Your files are still on the disk. Erasing rebuilds the APFS structure and can overwrite the very metadata that a recovery tool would need to get your files back.

Work through the steps below in order, and only consider erasing once your data is safely copied somewhere else.

First, confirm the drive is being seen

• Open Disk Utility, in Applications, then Utilities

• Choose View menu, then Show All Devices

• Look for your drive and the volume on it

If the volume appears in the sidebar but is greyed out, the drive is being seen and the volume simply is not mounted. That is the situation this FAQ covers, and your data is still there.

If the drive does not appear at all, this is a connection or hardware problem rather than a directory problem, and the steps below will not help.

There is no directory rebuild tool for APFS

Disk Utility’s First Aid is the only repair tool Apple provides, and what it can fix is limited. It handles minor inconsistencies well. It frequently cannot recover a volume that has stopped mounting altogether.

There is no third party utility that rebuilds a damaged APFS directory either, from Apple or from anyone else. This is a limitation of APFS itself, not a fault in your drive, and it is why the steps below move fairly quickly from repair attempts to recovering your data.

Step 1: Restart, and check for a stuck disk check

Before anything else, disconnect the drive, restart your Mac, and reconnect. This on its own resolves a surprising number of cases.

A volume will also refuse to mount if macOS has a disk check process stuck in the background from an earlier attempt. This is a common cause of the 49218 error in particular. To clear it, open Terminal, in Applications, then Utilities, and enter:

sudo pkill -f fsck

Then try mounting the volume again in Disk Utility.

Only do this if you are certain no repair is deliberately running. If you have started a First Aid or fsck repair and it is still working, let it finish, however long it takes.

Step 2: Run First Aid

Limited though it is, First Aid is quick and is worth trying.

• Open Disk Utility and choose View menu, then Show All Devices

• Start at the top. Select the physical drive itself and click First Aid

• Then select the APFS container beneath it and run First Aid again

• Then select the volume inside the container and run First Aid on that

Always work from the top down. Checking the physical drive verifies the partition map, and repairing a container can resolve problems that only show up at the volume level.

Step 3: Try a different Mac, or a different macOS version

This is simple, costs nothing, and works more often than you might expect.

Connect your drive to another Mac, or start up from a different startup volume if your Mac has more than one macOS installation. A different version of macOS will sometimes mount a volume that your current system refuses, and the act of mounting it can trigger macOS to carry out repairs it had been deferring.

If the volume mounts on the other system, copy your data off immediately, before doing anything else.

A Windows PC running MacDrive is worth trying for the same reason. MacDrive reads and writes APFS, HFS+, and encrypted APFS volumes natively, including SoftRAID volumes, and includes its own disk repair tools. Because it is a separate implementation of APFS rather than Apple’s, it will sometimes read a volume that macOS will not, which at minimum gives you a route to copy your files off.

Step 4: Find your volume’s device identifier

The Terminal commands in the next step need to know which volume to work on. macOS identifies each one with a short device identifier in the form diskXsY, for example disk5s1.

To find it in Disk Utility:

• Open Disk Utility and choose View menu, then Show All Devices

• Select your volume in the sidebar

• Press Command-I, or right click the volume and choose Get Info

• Find the entry labeled Device, or BSD device node. That is your identifier

Write it down, and do the same for the APFS container listed above your volume, since you may need both.

Be careful to note which is which. An APFS container and the volumes inside it have unrelated numbers. A container whose physical store is disk3s2 might hold a volume called disk5s1.

Tip: if you are comfortable in Terminal, entering diskutil list gives you the same information as a single list.

Step 5: Check and repair from Terminal

macOS includes a command line tool called fsck_apfs which can perform checks and repairs that Disk Utility does not expose. It is the same underlying tool First Aid uses, but you have more control over how it runs.

Open Terminal, in Applications, then Utilities.

How to run each of the commands below:

• Copy the command

• Paste it into the Terminal window

• Press Return

• Terminal will ask for your password. Type your normal administrator password, the one you use to install software. Nothing at all will appear as you type it, not even dots. This is normal and does not mean the keyboard has stopped working

• Press Return again

In each command, replace disk5s1 with the identifier you found in Step 4.

Check the volume without changing anything. This is read only and makes no modifications to your disk:

sudo fsck_apfs -n /dev/disk5s1

Read the output and note any errors it reports.

Attempt a repair. This one does write changes to the volume:

sudo fsck_apfs -y /dev/disk5s1

If the command reports that the volume could not be unmounted, unmount the whole device first, replacing disk5 with the whole disk identifier, with no s and no second number:

diskutil unmountDisk /dev/disk5

Then run the repair command again.

If the repair succeeds, try mounting the volume:

diskutil mount /dev/disk5s1

Before you run these, a few things to know:

Repairs are not guaranteed. If fsck_apfs reports that the container superblock is invalid, or that the volume could not be verified, the damage is beyond what Apple’s built in tools can repair. Move on to Step 7

If the data is valuable and you have no current backup, consider going straight to Step 7. A repair attempt writes to the volume, and in rare cases that can make a later recovery harder

Side note: more than one volume in a container

Most people have a single volume inside an APFS container, and if that describes you, you can skip this.

If you do have several volumes sharing one container, it is worth knowing that APFS repairs act on the whole container rather than on one volume in isolation. If any volume in that container is mounted, a repair cannot run, even when the mounted volume is not the one giving you trouble.

The diskutil unmountDisk command above handles this for you, because it unmounts everything on the device at once. You can see which volumes share a container in Disk Utility, with Show All Devices turned on: they are listed together underneath it.

Side note: RAID volumes

These instructions work on all APFS volumes. If the volume is on a RAID, run all of these commands against the RAID volume itself, never against the individual member disks inside the array.

Before going further, check that the RAID itself is healthy. A volume that will not mount because disks are missing is a different problem, and nothing in this FAQ will fix it. SoftRAID users should open SoftRAID and check the volume and disk tiles first. See our FAQ: RAID Failure and Missing Disks.

Step 6: Try again in macOS Recovery Mode

If the repair would not run, or ran but did not fix the problem, try it again from macOS Recovery. Nothing is mounted in Recovery, and macOS is both more able and more willing to complete repairs there than it is on a running system.

To start up in Recovery:

Apple silicon Macs: shut down, then press and hold the power button until you see Loading startup options. Click Options, then Continue

Intel Macs: restart and hold Command-R until you see the Apple logo

Once there, open Utilities menu, then Terminal, and repeat Step 5. You can also run First Aid again from Disk Utility in Recovery, which is worth doing even if it failed earlier.

Check your device identifier again once you are in Recovery. The numbers are assigned as devices are found, so they can differ from what you saw on your normal system.

Step 7: Recover your data

If the volume still will not mount, the remaining option is to recover the files off it with data recovery software. These tools read the disk directly and reconstruct what they can find, rather than depending on the directory that macOS cannot read.

Two that are widely used on the Mac:

Disk Drill (by CleverFiles)

R-Studio (by R-Tools Technology)

Both offer free trials, and this matters more than it might appear. The trial will scan your volume and show you what it found before you pay for anything. Use it to confirm that your file names, your folders, and your organization all come back, not just the raw files. Recovery software can sometimes return your data as thousands of unnamed files in a single folder, which is a great deal less useful than a recovered directory. Check what the trial shows you before you buy a license.

You will also need a second drive with enough free space to recover onto. Never recover files back onto the volume you are recovering them from.

Once your data is safe

After you have recovered your files and checked that they open correctly, you can erase and recreate the volume and restore your data to it.

If the volume stopped mounting after a power loss or a kernel panic, consider a UPS. Sudden power loss during a write is one of the more common causes of APFS directory damage.

Related FAQs

Should I format my volume as APFS or HFS+?
How much free space is recommended for APFS volumes?

If your volume is a SoftRAID volume

RAID Failure and Missing Disks
Is SoftRAID compatible with other utility programs?
Why should I use a UPS with RAID 4 or RAID 5?