I got the hint about sftp and tried filezilla. Logged in fine, copied the file, rebooted the drobo. Then... nothing. Drobo has restarted, but I can't reconnect to it in drobo dashboard, can't ssh back in, can't get in via filezilla either. So now I'm a little concerned. Update: Never mind! It just took a disturbingly long time to boot and get all loaded up. I was able to check out bittorrent sync and I did successfully update versions! Thank you for your help! Another update: Original problem was that bittorrent sync 1.0.132 on my drobo was maddeningly almost-not-quite-working: I managed to get it to sync from the drobo to other computers, but no real two-way sync. I can now confirm that version 1.3.94 on my drobo works perfectly. Thanks again!