After disconnecting an iscsi target on server A, then getting it connected on server B, it only said: "The disk is offline due to an policy set by the administrator".
I'm the administrator, and I did not set a policy. Well. This one was actually easier than I first thought...
Go into Computer Management -> Storage Right click on the disk and click online. (This does not show up when clicking on the partition, you have to click the grey square on the left)
I went back and forth trying to have the target on both computers, reading about cluster services and stuff, and after googling the error message, although sometimes the solution is easier...
