macOS CatalinA -Who knows this message (hard disk utility first aid) - Warning: MT mapping is not completely referenced?

Greetings to you!

For now; hope you are all healthy !?

To my question:

1) Who knows this message (hard disk utility first aid) - Warning: MT mapping is not completely referenced?
Now had no (or only the usual Catalina) problems, but occasionally run first aid over it.
This message comes at "Container disc2" at the end of the check. The same when checking from "Fusion Drive". The same message comes.
With Macintosh HD 1 + 2 data - does this message not appear?

Couldn't find much about it on the net, tried some suggestions https://discussions.apple.com/thread/251159425 but didn't do anything. Ne reinstall. I still did before I don't know what that means - I have backups with TM anyway. That with the reinstall. was a recommendation to fix the problem - whatever the consequences could be ....?

2) Did someone check that with "first aid"?
3) If so. Does this message come from Erste H. only for "Container disc2" and "Fusion Drive"?

I found that after Catalina installation. Clean installation didn't help either?
I was unfortunately not able to load a ScreenShot ??
Up vote post of jeckyl Down vote post of jeckyl
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Posted by
jeckyl
Reply

  • I've had this error for over a year on Catalina, Big Sur, and now just checking on Monterey as well. I've been scanning for an answer to this for over a year and nothing so don't hold your breath. Best thing I can tell you is don't sweat it, everything is running fine. It would be nice if someone from Apple stepped up and answered this question considering how much money their customers put out to purchase a high end quality product. but Hey, what do I know.

    —
    mrtkoto
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Accepted Reply

After I can't upload a link ScreenShot...

Run first aid on "Container disk2"

The computer does not respond while the startup disk is being checked.

Check storage system
Use live mode.
Execute fsckapfs -n -x -l / dev / disk0s2
Checking the container superblock.
Checking the fusion superblock.
Checking the EFI jumpstart record.
Checking the space manager.
Checking the space manager free queue trees.
Checking the object map.
Checking the Fusion data structures.
Checking volume.
Checking the APFS volume superblock.
The volume Macintosh HD - Data was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking snapshot 1 of 2 (com.apple.TimeMachine.2020-07-29-150921.local)
Checking snapshot 2 of 2 (com.apple.TimeMachine.2020-07-29-170616.local)
Checking the extent ref tree.
Checking the fsroot tree.
Checking volume.
Checking the APFS volume superblock.
The volume Preboot was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking the extent ref tree.
Checking the fsroot tree.
Checking volume.
Checking the APFS volume superblock.
The volume recovery was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking the extent ref tree.
Checking the fsroot tree.
Checking volume.
Checking the APFS volume superblock.
The volume VM was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking the extent ref tree.
Checking the fsroot tree.
Checking volume.
Checking the APFS volume superblock.
The volume Macintosh HD was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking snapshot 1 of 2 (com.apple.TimeMachine.2020-07-29-150921.local)
Checking snapshot 2 of 2 (com.apple.TimeMachine.2020-07-29-170616.local)
Checking the extent ref tree.
Checking the fsroot tree.
Verifying allocated space.
warning: MT mapping (0x4000004048a40 -> 0x12ceb94, 164, C) is not completely referenced
warning: MT mapping (0x4000004048bb8 -> 0x12cecfa, 344, C) is not completely referenced
warning: MT mapping (0x4000004048dff -> 0x12cef11, 106, C) is not completely referenced
warning: MT mapping (0x40000040dd7fd -> 0x1354f87, 32, C) is not completely referenced
warning: MT mapping (0x40000040f24b7 -> 0xa5ef4d, 1, C) is not completely referenced
warning: MT mapping (0x40000040f8294 -> 0x850e9a, 2, C) is not completely referenced
warning: MT mapping (0x40000040fff30 -> 0x137268b, 164, C) is not completely referenced
warning: MT mapping (0x40000041000a8 -> 0x13727f1, 190, C) is not completely referenced
warning: MT mapping (0x40000041075f7 -> 0xa5ebe9, 1, C) is not completely referenced
warning: MT mapping (0x400000410760b -> 0x1377f47, 8, C) is not completely referenced
warning: MT mapping (0x400000410761c -> 0xa5ebf1, 1, C) is not completely referenced
warning: MT mapping (0x400000410761d -> 0x1377f57, 8, C) is not completely referenced
warning: MT mapping (0x4000004107625 -> 0xa5ebfe, 1, C) is not completely referenced
warning: MT mapping (0x4000004107626 -> 0x1377f5f, 8, C) is not completely referenced
warning: MT mapping (0x4000004107aec -> 0x13782f6, 24, C) is not completely referenced
warning: MT mapping (0x4000004107b05 -> 0x137830e, 32, C) is not completely referenced
warning: MT mapping (0x4000004107b26 -> 0x137832e, 24, C) is not completely referenced
warning: MT mapping (0x4000004107b3f -> 0x1378346, 32, C) is not completely referenced
warning: MT mapping (0x400000410a877 -> 0xd296fd, 6, C) is not completely referenced
The volume / dev / disk0s2 appears to be OK.
Storage system check exit code is 0.

Operation successful.

what is to blame for the mistake?
Posted by
jeckyl
Up vote reply of jeckyl Down vote reply of jeckyl
Post marked as solved

  • Why is this marked as an accepted answer, when the post doesn't give any answer.

    —
    harirajanv

  • One thing I can add, if you go through terminal using the diskutil (verifyVolume) /dev/disk2s1 etc and verify each volume of your Fusion you should NOT see the message, at least I never have.

    —
    mrtkoto
Add a Comment

Replies

After I can't upload a link ScreenShot...

Run first aid on "Container disk2"

The computer does not respond while the startup disk is being checked.

Check storage system
Use live mode.
Execute fsckapfs -n -x -l / dev / disk0s2
Checking the container superblock.
Checking the fusion superblock.
Checking the EFI jumpstart record.
Checking the space manager.
Checking the space manager free queue trees.
Checking the object map.
Checking the Fusion data structures.
Checking volume.
Checking the APFS volume superblock.
The volume Macintosh HD - Data was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking snapshot 1 of 2 (com.apple.TimeMachine.2020-07-29-150921.local)
Checking snapshot 2 of 2 (com.apple.TimeMachine.2020-07-29-170616.local)
Checking the extent ref tree.
Checking the fsroot tree.
Checking volume.
Checking the APFS volume superblock.
The volume Preboot was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking the extent ref tree.
Checking the fsroot tree.
Checking volume.
Checking the APFS volume superblock.
The volume recovery was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking the extent ref tree.
Checking the fsroot tree.
Checking volume.
Checking the APFS volume superblock.
The volume VM was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking the extent ref tree.
Checking the fsroot tree.
Checking volume.
Checking the APFS volume superblock.
The volume Macintosh HD was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking snapshot 1 of 2 (com.apple.TimeMachine.2020-07-29-150921.local)
Checking snapshot 2 of 2 (com.apple.TimeMachine.2020-07-29-170616.local)
Checking the extent ref tree.
Checking the fsroot tree.
Verifying allocated space.
warning: MT mapping (0x4000004048a40 -> 0x12ceb94, 164, C) is not completely referenced
warning: MT mapping (0x4000004048bb8 -> 0x12cecfa, 344, C) is not completely referenced
warning: MT mapping (0x4000004048dff -> 0x12cef11, 106, C) is not completely referenced
warning: MT mapping (0x40000040dd7fd -> 0x1354f87, 32, C) is not completely referenced
warning: MT mapping (0x40000040f24b7 -> 0xa5ef4d, 1, C) is not completely referenced
warning: MT mapping (0x40000040f8294 -> 0x850e9a, 2, C) is not completely referenced
warning: MT mapping (0x40000040fff30 -> 0x137268b, 164, C) is not completely referenced
warning: MT mapping (0x40000041000a8 -> 0x13727f1, 190, C) is not completely referenced
warning: MT mapping (0x40000041075f7 -> 0xa5ebe9, 1, C) is not completely referenced
warning: MT mapping (0x400000410760b -> 0x1377f47, 8, C) is not completely referenced
warning: MT mapping (0x400000410761c -> 0xa5ebf1, 1, C) is not completely referenced
warning: MT mapping (0x400000410761d -> 0x1377f57, 8, C) is not completely referenced
warning: MT mapping (0x4000004107625 -> 0xa5ebfe, 1, C) is not completely referenced
warning: MT mapping (0x4000004107626 -> 0x1377f5f, 8, C) is not completely referenced
warning: MT mapping (0x4000004107aec -> 0x13782f6, 24, C) is not completely referenced
warning: MT mapping (0x4000004107b05 -> 0x137830e, 32, C) is not completely referenced
warning: MT mapping (0x4000004107b26 -> 0x137832e, 24, C) is not completely referenced
warning: MT mapping (0x4000004107b3f -> 0x1378346, 32, C) is not completely referenced
warning: MT mapping (0x400000410a877 -> 0xd296fd, 6, C) is not completely referenced
The volume / dev / disk0s2 appears to be OK.
Storage system check exit code is 0.

Operation successful.

what is to blame for the mistake?
Posted by
jeckyl
Up vote reply of jeckyl Down vote reply of jeckyl
Post marked as solved

  • Why is this marked as an accepted answer, when the post doesn't give any answer.

    —
    harirajanv

  • One thing I can add, if you go through terminal using the diskutil (verifyVolume) /dev/disk2s1 etc and verify each volume of your Fusion you should NOT see the message, at least I never have.

    —
    mrtkoto
Add a Comment
I too am curious what is to blame for this warning and poor reference. It appears I have the exact same message in first aid. Also, I have had two start up disc failures 7 days apart, on top of some other strange things (like photos not responding). Current solutions in between startup disc failures were to complete first aid, reset SMC, reset NVRAM, and ultimately reformat volume and reinstall (clean) OS 10.15.x. I found that recovering from time machine ate up about 250gb of my 1tb hard drive. I did not think to check first aid on volume until after initial time machine recovery. I am concerned one or both parts of the fusion hard drive are failing.
Posted by
lasleym
Up vote reply of lasleym Down vote reply of lasleym
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Has anyone ever helped you with this? I also get these mapping errors and like you said it's next to impossible to find any good intel about it on google.

Can someone please advise if they know anything about this. I've been dealing with it for months.

Running First Aid on “Container disk2”

Verifying the startup volume will cause this computer to stop responding.

Verifying storage system
Using live mode.
Performing fsckapfs -n -x -l /dev/disk1s2
Checking the container superblock.
Checking the fusion superblock.
Checking the EFI jumpstart record.
Checking the space manager.
Checking the space manager free queue trees.
Checking the object map.
Checking the Fusion data structures.
Checking volume.
Checking the APFS volume superblock.
The volume Macintosh HD - Data was formatted by diskmanagementd (1412.141.1) and last modified by apfskext (1412.141.1).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
warning: MT mapping (0x40000002d013b -> 0x4fdcef, 1, C) is not completely referenced
warning: MT mapping (0x400000037350d -> 0x11657e, 1, C) is not completely referenced
warning: MT mapping (0x400000037350e -> 0x4083da, 3, C) is not completely referenced
warning: MT mapping (0x4000000373516 -> 0x4083e0, 3, C) is not completely referenced
warning: MT mapping (0x400000049a588 -> 0x4f8062, 1, C) is not completely referenced
warning: MT mapping (0x40000011b6317 -> 0x4087a8, 3, C) is not completely referenced
warning: MT mapping (0x40000011b6cdd -> 0x408b91, 3, C) is not completely referenced
warning: MT mapping (0x40000011b6ce3 -> 0x2c011b, 4, C) is not completely referenced
warning: MT mapping (0x40000011b6ce7 -> 0x42087a, 2, C) is not completely referenced
warning: MT mapping (0x40000011b6cfb -> 0x2c0106, 4, C) is not completely referenced
warning: MT mapping (0x40000011b6d6e -> 0x2c0123, 4, C) is not completely referenced
warning: MT mapping (0x40000011b6df5 -> 0x4087b4, 3, C) is not completely referenced
warning: MT mapping (0x40000011b6e03 -> 0x408b8b, 3, C) is not completely referenced
warning: MT mapping (0x40000011b70f2 -> 0x408ba6, 3, C) is not completely referenced
warning: MT mapping (0x40000011b726b -> 0x2c013f, 4, C) is not completely referenced
warning: MT mapping (0x40000011b7283 -> 0x2c013b, 4, C) is not completely referenced
warning: MT mapping (0x40000011b728f -> 0x2c0133, 4, C) is not completely referenced
warning: MT mapping (0x40000011b729b -> 0x2c012f, 4, C) is not completely referenced
warning: MT mapping (0x40000011b72a4 -> 0x2c0137, 4, C) is not completely referenced
warning: MT mapping (0x40000012848a6 -> 0x247574, 1, C) is not completely referenced
warning: MT mapping (0x40000020003ed -> 0x33274a, 1, C) is not completely referenced
warning: MT mapping (0x4000002002087 -> 0x3362fd, 2, C) is not completely referenced
warning: MT mapping (0x4000002002225 -> 0x3363b3, 2, C) is not completely referenced
warning: MT mapping (0x4000002029a00 -> 0x1a6735, 1, C) is not completely referenced
warning: MT mapping (0x40000022493f1 -> 0x259c0b, 2, C) is not completely referenced
warning: MT mapping (0x4000002291309 -> 0x18754c, 1, C) is not completely referenced
warning: MT mapping (0x400000229dfdc -> 0x498d00, 1, C) is not completely referenced
warning: MT mapping (0x400000229dfdf -> 0x498d01, 1, C) is not completely referenced
warning: MT mapping (0x400000229dfe0 -> 0x25992f, 2, C) is not completely referenced
warning: MT mapping (0x40000025c065b -> 0x3f94eb, 1, C) is not completely referenced
warning: MT mapping (0x40000026604e9 -> 0x49ef38, 1, C) is not completely referenced
warning: MT mapping (0x40000026604ee -> 0x49ef3d, 1, C) is not completely referenced
warning: MT mapping (0x4000002663fab -> 0x4b2fb3, 1, C) is not completely referenced
warning: MT mapping (0x40000028577a9 -> 0x388406, 1, C) is not completely referenced
warning: MT mapping (0x400000285d2ab -> 0x38de3b, 1, C) is not completely referenced
warning: MT mapping (0x400000285d2b0 -> 0x38de40, 1, C) is not completely referenced
warning: MT mapping (0x400000285d2b1 -> 0x25c8ad, 4, C) is not completely referenced
warning: MT mapping (0x400000293743c -> 0x19bb67, 1, C) is not completely referenced
warning: MT mapping (0x40000029b8e92 -> 0x4bace2, 1, C) is not completely referenced
warning: MT mapping (0x40000029edc07 -> 0x1eb282, 1, C) is not completely referenced
warning: MT mapping (0x4000002abb035 -> 0x1ea961, 1, C) is not completely referenced
warning: MT mapping (0x4000002abc8c5 -> 0x1ecb21, 1, C) is not completely referenced
warning: MT mapping (0x4000002ae4df7 -> 0x62e635, 1, C) is not completely referenced
warning: MT mapping (0x4000002b9e962 -> 0x4a5232, 1, C) is not completely referenced
warning: MT mapping (0x4000002ba36bd -> 0x1f24a5, 1, C) is not completely referenced
warning: MT mapping (0x4000002ba36be -> 0x1dd22e, 4, C) is not completely referenced
warning: MT mapping (0x4000002bb59e2 -> 0x1a4d57, 1, C) is not completely referenced
warning: MT mapping (0x4000002cdc5a9 -> 0x25ebc4, 1, C) is not completely referenced
warning: MT mapping (0x4000002cf1ab9 -> 0x1a1f42, 1, C) is not completely referenced
warning: MT mapping (0x4000002cfb8e3 -> 0x1ee246, 1, C) is not completely referenced
Too many warnings of this type generated; suppressing subsequent ones.
The volume /dev/disk1s2 appears to be OK.
Storage system check exit code is 0.

Operation successful.


Posted by
benz-tone
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I have run Disk Utility on fresh install of Catalina (done a week ago) after disk wipe on the Fusion drive of an iMac and I get the same crap, a bunch of: warning: MT mapping (****************) is not completely referenced

My last iMac is quite old (and its Disk Utility is not quite as crippled or dumbed down) and Disk Utility also always produced tons of problems with references that never went away and never seemed related to any known problem (because there weren't any). I too would like to know what gives. We have a critical utility that seemingly does the bare minimum and yet finds problems (my assumption is that they are) of little consequence except they are a perpetual annoyance and therefore should be sufficiently explained or somehow done away with.
Posted by
supernaught
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Count me in with the same issue. And, I too suspect the fusion drive is at fault. I've had to rebuild my hard drive (3 TB Fusion) twice on a 2019 iMac 27" 5k model fully loaded. This is complete unacceptable so I'm taking it back to Apple under AppleCare and insisting on a complete replacement of the 3 TB Fusion drive. Disk First Aid, and the troublesome APFS/containers confusion, always reports this error. How do I know there is a problem? Finder slows to a complete crawl...beachballing...the computer becomes unusable. Couple in "snapshots" and "Time Machine" either capturing the bad blocks or replicating them on restores, and I'm left praying for Steve Jobs incarnation, you know, when Apple "just worked."

Posted by
Stuke
Post not yet marked as solved Up vote reply of Stuke Down vote reply of Stuke

  • me too have exact issue.. OS Catalina.

    have tried to reinstall using internet recovery , but the error still continues.reset fusiin and reinstall, stil the same issue.

    initiall those 'nt mapping' errors were few, login didn't effect... but then slowly the number of entries have increased, so now login takes 1hr or so, with beachball .. any action after login just a click takes another 30mins or so with beachball. cannot work at at.

    Is any Apple developer around to look and let us know surely it should be easy peasy to say what the code is referring to and what it is complaining about. without source code, it is really hard to say what is happenning. or atleast inform what to look for and where.

    Thanks.

    —
    harirajanv

  • I'm adding to this because I am having the same problems. I've had to wipe and reinstall my 2019 apple MacBook Pro 8 times since buying it. I keep getting a random Hd-Data-Data that always shows up at some point. Trying to fix it I've stumbled on this problem, except on disk 3 which was corrupt. Here's my anger , I took it into the apple store for repair along with a battery service. I even was on the phone prior to bringing it in with tech. I brought it in, it was shipped to Texas. Now, I can't work without my computer so at this point I am down 3 days working, aside from all the times I rebuilt my hardirive because O didn't want to use time machine of that was somehow causing a problem. I got the computer back turned it on right in recovery where I left it. Still with a corrupt hard drive! When I called to get something actually done they told me to send it in again. Losing even more work, I couldn't. They said they wouldn't replace or at least help cover a significant cost of an M-1 Mac unless I sent in 3 times and that there were no none issues like mine. So stumbling on this forum is exactly what I needed. They tried telling me this was a tech issue and I had to remind them this is a customer service issue just as much as a tech issue. If I order steak at a restaurant and get the wrong thing because the server does a bad job can they make me pay for the meal and blame the kitchen, no! That being said I haven't found anyway to fix this issue, except using disk drill to recover lost files and onyx. Still can't fix the corrupt hard drive, and I ran a diagnotic with an AP000 code its not a hardware problem. If anyone does have an answer I'd try anything. I feel like they gave up on the intel line, as a result there are major issues. I still have 1 year on AppleCare. I can't afford to send my Mac off at leisure. I thought about small claims court because of the lost work. Another story though. I'm just sharing this because I hope Apple does read it and if anyone else is having these issues they are lying when they say no one is, and that was a senior tech.

    —
    thrvoodooosoul

  • I'm also adding to this as I am having the exact same problem with a client's 2017 27" 5K iMac with a 3TB Fusion drive running Monterey 12.4

    —
    AKMacGuy
Add a Comment

Trying to spread the word here. I was having this same issue. After a lot of trial and error and searching online, I followed the steps on this Apple support page and it completely fixed the issues I was having with my fusion drive: https://support.apple.com/en-us/HT207584

It was super easy if you're running Mojave or later. Literally just one command in terminal!

Posted by
JupiterDan117
Up vote reply of JupiterDan117 Down vote reply of JupiterDan117

  • If you do this, it will erase your computer. It might fix the problem, but resetting your Fusion Drive means completely erasing it and starting fresh.

    —
    ismoody
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It only fixes the problem with a shared Fusion drive, but not the error - This is Wrong: warning: MT mapping (0x4000000738f36 -> 0x66b00e, 24, C) is not completely referenced

Posted by
jeckyl
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I have had this error on my 2017 mid 5k iMac 27in. As another posted if you run the diskutil-verification tool you shouldn't see it BUT that does not excuse apple for not addressing this problem. The amount of $ we all spend you would think someone would of the common decency to post SOMETHING about this MT-Mapping problem that has been happening for two years now. Welcome to customer server 2021. No CSR's answer you and they have search engine algorithm's so jacked up because of the suppression tools it makes a simple search turn into a ready to throw out the window situation.

Posted by
mrtkoto
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I'm also adding to this because I am having the exact same problems with a client's 2017 27" 5K iMac with a 3TB Fusion drive running Monterey 12.4. Apple needs to address this issue as I have scoured the web and this is the only legitimate forum I can find discussing this unsolved issue. I am loath to spend the time and the commensurate expense to the customer remerging a Fusion drive that isn't broken ( https://support.apple.com/en-us/HT207584 ), reinstalling the Mac OS, and restoring from Time Machine just to have the problem reappear as is suggested by some of the above posts. Come on Apple, make an effort to FIX THIS PROBLEM.

Posted by
AKMacGuy
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Same issue with my 2019 27" 5K iMac with a 1TB Fusion drive running Monterey 12.4

Found when looking why the computer keeps freezing and doesn’t seem to ever get rid anything from the memory (unable to start on recovery mode)

Posted by
Alkoreiel
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