I am using Kubuntu 22.04 and found that all partitions on three drives were being auto mounted. I found a site that said I could stop this by issuing the command:I did this, and it worked, and no drives were mounted on rebooting except those in fstab

However, when I plug in a usb drive, nothing happens. So I tried reversing the command with I get an errorRebooting, no drives are mounted, and inserting a usb drive draws a blank.

How do I get usb auto mounting working again??

That's not my experience with kubuntu 22.04. Items not listed in fstab are not auto mounted on both a fresh install of 22.04 and an upgrade install from 20.04. It's probably a kde configuration issue. Check in System Settings > Removable Devices > Attached Devices. You may be able to get your desired behavior re auto mounting by setting things up in there. Note, for me, something odd is going on in System Settings > Removable Devices > Attached Devices. Partitions which are not on removable media(i.e. are on drives installed in the box) are listed under Attached Devices.

Thank you kilgoretrout
It's all very confusing. Comparing initial installs: Kubuntu 20.04 does not auto mount partitions. However a Neon 5.6/Ubuntu 22.04 does auto mount available partitions. The Neon Settings/Hardware/Removable Storage/Attached Devices is not editable. I don't know why or when my Kubuntu 22.04 suddenly decided to mount other partitions. I suspect I have seen this happen on other Mint install also. Kubuntu 22.04 Settings has a menu item Storage Devices, which enables editing mount at log on. I have seen it stated on web sites:However, I created my problem making a typo, as indicated by the error message referred to in my first post. I omitted an 's' in udisks2, and restored usb mounting with:

I am still vexed by Kubuntu 22.04 insisting on mounting all partitions at boot.

System Settings, Removable Devices, lists all attached devices (partitions), with two columns of boxes on the right labelled 'On Login' and 'On Attach'. None of these is checked, which suggests none will be mounted. BUT on booting they are all mounted. Does this matter? Yes if you want to keep data on those partitions safe.

The only way I have found to stop auto mounting all partitions is to issue the commandThe problem then is that when plugging in a usb device it cannot be mounted!

Why? How are you trying to mount it manually?

Issue:
Plug the usb device in, see what device node it is, mount it.

Example:
Of if it's a ntfs volume, and you are still using ntfs-3g:
You need to give more info about what you are doing.

This is puzzling. My 22.04 installations do not auto mount unless set to auto mount in fstab. And attached is a screenshot of System Settings>Removable Devices>Attached Devices. Even entries that have the "On Attached" box ticked do not auto mount without an entry in fstab.The only thing I would suggest as a workaround is to create entries in fstab for all partitions you don't want auto mounted and explicitly have them set noauto.

Attached Thumbnails

 

Thank you teckk
Normally, when a usb device is plugged in, it is detected and a window pops up at the bottom right with options. After issuing the command systemctl mask udisks2 that was not happening, and there was no option to mount the usb inspecting the usb widget. That is what I meant when I said the usb device could not be mounted. In other words, the usb removable device was masked.

and thank you kilgoretrout
Referring to your screenshot, on my system it does not matter whether all boxes are checked or unchecked (empty), on fresh boot 16 partitions are listed in Dolphin under Devices. Clicking any one opens the partition in /media/john/ without need of a password. This is what I referred to as auto mounting. Is this to be expected?? I have believed that generally mounting needs to be commanded by administrator directly or indirectly.

If I issue the commandno partitions are listed in Dolphin under Devices. However plugging in a usb device does not initiate the pop up window at bottom right as explained to teckk

Found this:https://askubuntu.com/questions/2116...ing-partitions

OK. Now I get it. That's not what I would call auto mounting but rather user mountable without password in dolphin. Same behavior here. Also, I tried creating an entry in fstab for a partition with noauto and that didn't change that behavior; I could still mount the partition in dolphin without a password, although the mount point changed to the one designated in fstab. You can right click any item in dolphin > Devices and hide it as a workaround.

You're using systemctl udisks2 to modify this behavior. The udisks man page provides:

https://manpages.ubuntu.com/manpages.../udisks.8.html

The "Access Control" section of the above provides in relevant part:
I'm not familiar with that option, but it may provide a way to do what you want. Also, polkit configuration may do it as well as indicated in the link posted by colorpurple.

Edit: Additional information. This appears to be a ubuntu configuration issue with respect to udisks and polkit. I checked this behavior in my installations of Mageia, Arch, OpenSuse and Debian. In every case, when I clicked on a partition in dolphin that was not mounted in fstab, I was prompted for a password before the partition would mount.

Thank you colorpurple. I will experiment with you reference.

and kilgoretrout
Bingo! The Mageia, Suse, etc response is just the security behavior I was expecting and aiming at.

Following colorpurple reference, I did:On rebooting, internal drives were listed in Dolphin. They were not open in /media/john.
Clicking a partition asked for password, and mounted in /media/john
Plugging in a usb device was recognised, and could be opened without a password.

Just what I was looking for.
Thank you all for baring with me.