error 49218 - RAID/Hard drive mot mounting

Hello yoni1231,

If you can't mount or run First Aid on the drive in Disk Utility on this MacBook Pro, the only other suggestion we would have is to test the hard disk on another Mac, if applicable.

If the same issue happens on both Macs, then we would say the issue is with the hard disk itself.

Hope this helps out.

Take care.

I have the same issue, with a brand new Samsung T7 Shield SSD. I run Disk Utility First Aid, and it checks out fine, with no error message, other than the usual :

Could not mount “AppleAPFSMedia”. (com.apple.DiskManagement.disenter error 49218.)

I don't understand why it won't mount, and whether it means it's defective, or ?

Ok, here's a new quirk. I hooked it up to my older Macbook, which is on High Sierra, used an adapter to take it from USB 3 to a USB (1 or 2), and it was immediately recognized. I then ran First Aid on it, and it said it passed, however it showed dozens of a certain error, "invalid internal_flags", until it finally just said "too many warnings generated: suppressing subsequent ones" as in the photo below. So then I tried connecting to my iMac, using the same USB3 to USB, and it still won't mount! It's odd that it did with the Macbook, and that I was able to mount it and do a back-up at least once, maybe even twice, but could be just once, and did see everything when I opened the drive on my Macbook. However, other than that one time, it refuses to mount ever again, on my iMac. Does this tell you something? Or those odd "warnings" that First Aid found?

First, is the RAID still valid or has it degraded by a problem with one of the drives or some other issue?

Second, when running First Aid, try running First Aid on the whole physical drive so it can first verify the partition table is Ok. Then run First Aid on the hidden APFS Container (for a single APFS volume, it may not make a difference, but worth trying anyway). Within Disk Utility you may need to click "View" and select "Show All Devices" before the physical drives and hidden Containers appear on the left side of Disk Utility.

Unfortunately if Disk Utility is unable to repair an APFS volume, usually the only recourse is to erase the drive & restore from a backup. If this RAID used hard drives, then I would recommend utilizing HFS+ volumes instead of APFS volumes. I'm not sure if APFS volumes will wear the RAIDed hard drives as much as a single hard drive, but at least there is a third party utility available (Disk Warrior) which does a good job of repairing HFS+ volumes (they are currently working on adding APFS repair support).

If First Aid is unable to repair the volume, then you could try using the command line to see whether you can manually mount it as read-only in order to access the data to back it up to another location. Otherwise you can look into a data recovery app to attempt to retrieve the data, but you will still need other external media to contain any files recovered.

FYI, people should always have frequent and regular backups of their computer and all external media (including the cloud) which contains important & unique data. I know this is difficult & expensive to do with a 98TB drive, but it is still necessary if you value the data. The more important the data, then you should probably have more than one backup. Just remember RAID is not a backup....RAID is just a way of trying to keep your storage device running so you can continue to access the data when one of the drive fails.

yoni1231 wrote:

Thanks so much for your response. The drive itself says First Aid has been successful but it fails on the container and volume itself.

What are the exact errors it gives?

Would you happen to know the Terminal command to try and mount the drive as readOnly? When I try, it says I need to specify the filesystem with -t, I've tried adding -t APFS but that doesn't seem to work.

The traditional *nix "mount" command can be difficult to use on macOS since it usually requires everything to be specified. I've had a lot of issues using the basic *nix "mount" command.

For macOS it is best to use the "diskutil" command which is the command line version of Disk Utility (actually it is only one part of Disk Utility). While I have mounted various volumes with macOS using "diskutil", it has been a while since I mounted (or tried to mount) an APFS volume. APFS is a bit different at times.

You will need the correct drive identifier for the APFS volume. Here are two options for acquiring the drive identifier....I'm not sure how the an APFS volume will appear on an external drive so the first command may not be of any use here, but I'm providing it just in case since it will contain less information to sift through.

List external drives & their layouts:

diskutil  list  external

More likely the following command will be necessary to get the drive identifier for the APFS volume (you will need to find the APFS volume for the external drive....there will be several for the internal boot drive):

diskutil  ap  list

FYI, the "ap" in that command is just an abbreviation for "apfs" which could have also been used in its place.

When you have the correct drive identifier for the APFS volume on the external drive you want to mount, then use the following command making sure to replace "diskXsY" with the correct drive identifier which would look something like "disk3s1".

diskutil  mount  readOnly  diskXsY

One advantage to using the "diskutil" over the traditional *nix "mount" command is that "diskutil" will automatically create the folder for the mount point in "/Volumes" by using the name of the volume.

Saxman wrote:

I have the same issue, with a brand new Samsung T7 Shield SSD. I run Disk Utility First Aid, and it checks out fine, with no error message, other than the usual :

Could not mount “AppleAPFSMedia”. (com.apple.DiskManagement.disenter error 49218.)

I don't understand why it won't mount, and whether it means it's defective, or ?

It would be best if you started your own thread. The OP here has a slightly more complex setup than most users tend to have since the OP is using a RAID setup which adds complications to troubleshooting.

However, did you try all of the suggestions I presented to the OP in this thread?

I did seem to overlook one item for the OP. Even if First Aid says everything is "Ok", click "Show Details" and scroll back through the report to see if there are any unfixed errors listed. If there are any unfixed errors listed, then it will require erasing the drive & restoring from a backup. If you need the data from that drive because there is no backup, then using the command line to mount the drive as read-only may work. Or possibly data recovery software such as Data Rescue (there are other apps out there) may allow you to recover the data (will require another drive large enough to store any recovered data).

Like I mentioned previously, I believe your issue is different enough from the OP's issue that you should have your own thread...this last post of yours further confirms it since the behavior differs between two different Macs. Now we need to dig into the differences between your two Macs....this is why you should have your own thread instead of hijacking another thread which clearly mentioned a RAID was involved as opposed to a standard single external data drive. It gets really confusing for contributors when trying to assist multiple people in a thread where their issues are significantly different from one another even if you are receiving the same error message.

We need to know the exact models of those Macs and the version of macOS on each one. Plus you need to disconnect all other external devices from the Mac and confirm the drive is connected directly to the Mac. And it may be useful to know what cable & adapter is being used to connect the drive.

Your screenshot of First Aid shows your drive has APFS snapshots. Is this drive a macOS boot drive or is it a data only drive? What are those APFS snapshots from....having a backup app backing up this volume?

You need to be very careful with your words here. In your post you mentioned First Aid reported "errors", but the screenshot of First Aid is showing only "warnings". There is a difference between "warnings" and "errors". Typically "warnings" are things which can usually be ignored....those "warning" messages are usually only for the app developer. "Errors" are what you need to be worried about especially if they cannot be fixed.