I added entries to block the partitions on an external drive (via USB) from auto-mounting at boot time. I tried using the UUIDs, and the block names (/dev/sdc1). (I need to be using the UUIDs.)
UUID=xxxxxxxxxxxxxxxx /media/me/OS ntfs ro,noauto,nofail 0 0
/dev/sdc4 /media/me/OS ntfs ro,noauto,nofail 0 0
If I manually umount the partitions, I can mount them with
sudo mount /dev/sdc3 /media/me/OS
sudo mount -a does not remount the partitions.
The drive is a 500GB Seagate Blue. Three partitions are being auto-mounted. The file explorer dialog for each is opening. The dialogs are calling them "volumes." This disk is a copy of a failed disk I recovered with ddrescue.
This question is based on an earlier question I asked, How to Block Automounting of a Specific Drive (USB connection) With ** Three Mounted Partitions **