I setup an ISCSI drive at home for a secure backup raid, but also because of disk space. I run the mac pro 2013 and are a part time photographer. So use it for photo editing. The Synology RS816 is setup with normal shared folder, my dropbox/onedrive/googledrive/synologydrive, ISCSI with GlobalSan target on my MAC. So far I have successfully moved all my cloud service to the NAS so that the NAS sync all the files to the cloud service and make it independent from the mac itself. Then I could turn off my MAC without it need to sync first. Also free resources both disk space, ram, cpu since I do not have any other software running in the background while working. I have moved the other two users that I have on my mac to the ISCSI by right click on the user and choose advanced options. There I could choose a folder on external drive instead. That free up around 24gb right there. I moved the iTunes catalog/folder by pressing option key when starting iTunes, that let me create a new folder/catalog on my ISCSI drive. But when I try to backup my iPhone 256gb I am not able since there is not enough disk space. My SSD got 256gb, and had 33gb free before cleaning up. Now the next step.. default TEMP. I suspect that iTunes use default TEMP folder in Sierra even if the folder itself are located on the ISCSI drive. The TEMP is on my small SSD disk, so there would never be enough space. So does anyone have a clue about how to change the location of my TEMP file? Maybe also the application folder without moving my administrator user to the ISCSI? I do not want to move my default admin user to another drive.