Volume access blocked by ‘specialized access’.

Hello everyone. In spite of the narrow selection of the theme and product for this thread this is an issue that spans from Mac OS X.4.1 Tiger to Mac OS X.13.6 High Sierra and including PPC-PowerBooks as well as Intel-MacBook Pro. Having that said, I have access to OS from Mac OS 8.6 to 10.13 and are open for whatever solution that might be viable.

All of a sudden and without modifying the owner, user or group privileges in a long time several partitions (volumes) changed those settings hence blocking every normal possibility to gain access to those volumes. As I understand it the OS hasn’t either got access to the Volumes thus not being able to start from those volumes. It hangs after startup chime and presenting the apple on the grey screen. Strangely both the partitions on the internal drive was blocked at the same time, along with most of the partitions on two different external drives. I know I didn’t mess up all of those at the same time by changing any settings and this is the first time I experienced this since I started with Mac OS X in 2001!

With the purpose to speed up the process I’ll explain right away what I have tried to solve this. DiskUtility had the feature to repair the permissions until approximately Maverick or if it was Yosemite. Until El Capitan the feature could be executed through a shell in Terminal:

$ diskutil repairPermissions /Volumes/“Name of Volume"

$ diskutil repairPermissions /Volumes/Name\ of\ Volume

and to avoid the menace of not having access…

$ sudo diskutil repairPermissions /Volumes/“Name of Volume"

And without the knowledge of how to use the terminal commands I also tried use chmod and chown, cd and chdir. Another command that I’ve tried to use but without being able to change the location-volume is:

sudo /usr/libexec/repair_packages --verify --standard-pkgs /

The same problem exists with the application OnyX that only permits to repair the bootVolume.

I’ve used what I can find in OS X.4.11 Tiger, X.5.8 Leopard, X.12.6 Sierra y X.13.6 High Sierra but still without any success.

I have the application DiskWarrior but it’s not able to repair the volumes either. I thought that the application SuperDuper could repair the privileges in the process of making a copy but no way!

The best possible option would be to learn how to repair the access register using Terminal or some other application but at the same time I ask myself if it would be possible to just erase the location of all this register from:

/Volumes/MacOS/private/var/db/dslocal/nodes

I know that the joint knowledge is tremendous in this community but would still be surprised as well as pleased if someone could help me out with this issue.

Many thanks for your interest and commitment, Quique