Thanks for the quick reply! NOT all volumes are iSCSI (1 NAS which is working and displaying correctly).
I tried recreating the targets, but when I "Apply" the messages comes which reminds me to reset all connections. Tried that before, but still new targets wouldn't show up. Currently, we are copying data from the volumes, so I'd rather not try again right now (but will do later).
I have to mention that we had to run C-A-X Repair filesystem multiple times after crashes, and that the fsck did in some cases reveal errors. We had them fixed automatically.
Now when you're talking about symbolic links, I do get the impression that something on our system partition is not quite right anymore
Let me finish my copy jobs to be sure to have another backup of all the important data and then I'll try again a repair filesystem