SMB mount problem SOLVED!

[solouki]

Hi all,

This is a very specific problem that many individuals probably will never see, but it cost me roughly two days of effort to figure out how to recover SMB mounting so I thought it might save someone else some time and effort.

The problem arose because I had a MBP running 13.2 which had several external disks attached to it. I routinely (every day) SMB mount one or more of these drives onto other machines over the network (via SMB) because I require some of the data sets stored on these disks.
Last week I upgraded the MBP from 13.2 to 13.2.1, and suddenly lost the ability to SMB mount any of the attached drives.

I tried rebooting both machines, I tried switching OFF the Firewalls on both machines, I tried making sure that the proper ports were available on both machines for SMB, I tried switching OFF then back ON the File Sharing, I set all permissions so everyone could Read & Write to the drives, I tried HDDs and SSDs, I tried using "Connect to Server...", I tried using the Finder's directory commands, I tried manually mounting the drives using Terminal commands (mount -t smbfs ...), I tried NFS mounting, I even added the 13.2.1 machine to the Developers Seed and then upgraded to 13.3 beta, ... etc. Nothing worked. Finally, I tried an old HDD that was not attached to the MBP when it was upgraded, and low and behold, I could SMB mount this old disk! So I then compared the permissions on the old to the new drives, they were the same. I checked the extended attributes, and found that the drives that were attached to the MBP when the upgrade was performed, had the "com.apple.FinderInfo" extended attribute while my old HDD did not.

So I deleted the "com.apple.FinderInfo" extended attribute from the attached drives and immediately I was able to SMB mount them from other machines! Problem solved.

Take home message: If you are having problems SMB mounting disks over a network, check the extended attributes of the disks that you are attempting to SMB mount -- you may need to eliminate an extended attribute in order to perform the SMB mount. Second take home message: Always disconnect all attached drives before upgrading the OS, including the minor upgrades (such as 13.2 to 13.2.1, as I did). I normally disconnect everything before upgrading, but this was only a minor 13.2 to 13.2.1 upgrade, so I decided to save time -- and this brainfart mistake cost me a lot of time and effort.

Code:
ls -alO@ <disk-name>
xattr -d com.apple.FinderInfo <disk-name>

This lists the disk attributes and deletes the com.apple.FinderInfo attribute from the disk <disk-name>. After doing this, I was able to SMB mount the <disk-name> drive over the network.

Hope this helps someone...

Regards,
Solouki

EDIT:

P.S. I know this makes no sense, but I was getting desperate when nothing I tried was working so when I found that I could SMB mount an older, currently unused, disk, I then searched for any differences between the old and current disks. The only difference was the "com.apple.FinderInfo" attribute. I was shocked that immediately after deleting this attribute and before doing anything else, I now could SMB mount all of the disks! It would appear that the macOS update altered the extended attributes file on mounted drives that then killed SMB mounting...then changing/adding/deleting an extended attribute of the disk corrected this so the disk could then be SMB mounted.

 

[jpWaller]

Hi all,

This is a very specific problem that many individuals probably will never see, but it cost me roughly two days of effort to figure out how to recover SMB mounting so I thought it might save someone else some time and effort.

The problem arose because I had a MBP running 13.2 which had several external disks attached to it. I routinely (every day) SMB mount one or more of these drives onto other machines over the network (via SMB) because I require some of the data sets stored on these disks.
Last week I upgraded the MBP from 13.2 to 13.2.1, and suddenly lost the ability to SMB mount any of the attached drives.

I tried rebooting both machines, I tried switching OFF the Firewalls on both machines, I tried making sure that the proper ports were available on both machines for SMB, I tried switching OFF then back ON the File Sharing, I set all permissions so everyone could Read & Write to the drives, I tried HDDs and SSDs, I tried using "Connect to Server...", I tried using the Finder's directory commands, I tried manually mounting the drives using Terminal commands (mount -t smbfs ...), I tried NFS mounting, I even added the 13.2.1 machine to the Developers Seed and then upgraded to 13.3 beta, ... etc. Nothing worked. Finally, I tried an old HDD that was not attached to the MBP when it was upgraded, and low and behold, I could SMB mount this old disk! So I then compared the permissions on the old to the new drives, they were the same. I checked the extended attributes, and found that the drives that were attached to the MBP when the upgrade was performed, had the "com.apple.FinderInfo" extended attribute while my old HDD did not.

So I deleted the "com.apple.FinderInfo" extended attribute from the attached drives and immediately I was able to SMB mount them from other machines! Problem solved.

Take home message: If you are having problems SMB mounting disks over a network, check the extended attributes of the disks that you are attempting to SMB mount -- you may need to eliminate an extended attribute in order to perform the SMB mount. Second take home message: Always disconnect all attached drives before upgrading the OS, including the minor upgrades (such as 13.2 to 13.2.1, as I did). I normally disconnect everything before upgrading, but this was only a minor 13.2 to 13.2.1 upgrade, so I decided to save time -- and this brainfart mistake cost me a lot of time and effort.

Code:
ls -alO@ <disk-name>
xattr -d com.apple.FinderInfo <disk-name>

This lists the disk attributes and deletes the com.apple.FinderInfo attribute from the disk <disk-name>. After doing this, I was able to SMB mount the <disk-name> drive over the network.

Hope this helps someone...

Regards,
Solouki

EDIT:

P.S. I know this makes no sense, but I was getting desperate when nothing I tried was working so when I found that I could SMB mount an older, currently unused, disk, I then searched for any differences between the old and current disks. The only difference was the "com.apple.FinderInfo" attribute. I was shocked that immediately after deleting this attribute and before doing anything else, I now could SMB mount all of the disks! It would appear that the macOS update altered the extended attributes file on mounted drives that then killed SMB mounting...then changing/adding/deleting an extended attribute of the disk corrected this so the disk could then be SMB mounted.

What I found in testing was that the SMB disk did in fact get mounted, although it does not appear in the Finder user interface. When I tried to connect and could not, the network shared SMB disk did in fact appear under the " /Volumes/... " folder. However, it could only be seen with the Terminal. I could not do a " cd " or an " ls " command in Terminal to access the disk. But the disk is nonetheless mounted.

 

[MacGizmo]

FWIW, supposedly the latest Beta fixes the SMB mounting issue.

 

[jpWaller]

FWIW, supposedly the latest Beta fixes the SMB mounting issue.

I have tested Ventura 13.3 Beta and it does indeed seem to solve the problem.

 

[MikeDr206]

(bump)

So I had this issue on Ventura 13.4. File sharing *was* working (having my M1 MBA Ventura 13.4 access an external drive on my M2 Pro Mac Mini). I usually leave the Mini on all the time, but had to reboot.

File sharing stopped working.

It appears that the problem was that I had added the external drive to Spotlight Privacy, so Spotlight wouldn't search it. Ultimately, turning that off is what I believe fixed the problem.

That said, this was the ultimate workflow in case anyone else has this problem.

(1) removing the external drive from being shared;
(2) turning off file sharing;
(3) removing the drive from Spotlight Privacy;
(4) reboot;
(5) turn on file sharing;
(6) adding the external drive so that it was shared again.

I'm not sure if all these steps are necessary, or if only removing the drive from Spotlight Privacy was sufficient.

What was interesting is that when file sharing wasn't working, the smbd process didn't show up in Activity Monitor.

I believe that Apple's fix to file sharing, involving extended attributes, can be "broken" by adding a share to Spotlight Privacy, which presumably adds back the extended attributes (and in such a way that survives reboot).

 

[upritbass]

Huh, it worked. I can now see the external drives via smb using Files on the ipad. My external drives weren't in Spotlight Privacy, so I used steps 1, 2, 4, 5, 6.