BackupLoupe could even browse it, because, you know. I deleted the original and I was able to Finder copy the Synology copy to my local machine.

It copied well, no sign of a file system problem. I figured that was a bogus error message from a corrupt file, so I used Synology to copy the 200GB directory internally. Every time I tried it quit at about 54GB with a message like “The operation can’t be completed because you don’t have permission to access some of the items.” A different 60GB file copied normally. sparsebundle to a local drive so I could browse it efficiently. So then I installed a (long!) physical ethernet cable and tried Finder (AF) copying the. Nothing worked, I couldn’t make use of the existing backup. I tried various things to mount the old sparse bundle including disabling SMB, etc. I didn’t find anything - but did update my notes on the confusing configuration (every machine has a dedicated Synology username and quota). Instead I ran through a checkup of the NAS. sparsebundle from there (don’t even think of trying to do this through the Mac Finder) then start over.

The usual approach to this problem is to use the Synology web interface to run “File Station” and delete the. I can’t say if this was related to El Capitan or not, but I do wonder about El Cap’s relative deprecation of AFP (which Synology/Time Capsule needs). A few days after my carefully delayed update from Yosemite to El Capitan, Emily’s MacBook Air complained it couldn’t run its Time Machine backups to our Synology DS215j NAS.

Synology nas time machine long backup