I'm trying to link two directories on a Raidsonic IB-NAS4220. I've got two 1tb drives installed as hda and hdb mounted at mnt/ide1 and mnt/ide2. hda is almost full so i'm trying to move data from one to the other but retain the directory structure. I've googled and read lots of guides on symbolic links (they're not that complicated) but can't seem to get it to work properly. I've got a feeling it might be a bug with the nas. I can create a link from a directory on hda to hdb that works fine, the problem is as i cp data from hda to hdb the storage limit on hda is exceeded. I'm trying to move 500gb from hda to hdb, hda has ~30gb free space, hdb is empty but it seems the link is passing back the size of the folder on hdb to hda and cp exits with an insufficient space message. Have I missed something here or is this default behaviour?