can't reattach an HD

[fefele]

Hello everyone, my old man used to say "never touch something that works, there is a risk that does not work anymore." yesterday it happened: I pulled off a hd from webgui for a test and now I can not to attack him. the problem is that the disk is full of data! when I start the operation to reattach the disk I am asked if I want to set it with a new file system (UFS or ZFS) and this can not do it because I would lose data.

how do I fix? the other disks I mount them without any problems. help me please.