sparsebundle reverting to read-only I have a wireless drive [WD My Passport Pro] and of course I want to encrypt it, but of course there's no way to encrypt the actual drive with FDE and still have it recognized by the Passport's firmware, so I've created a sparsebundle within in encrypted with AES-256 with the drive physically attached to my Mac. I've been able to write to it, but as soon as I've accessed the sparsebundle from the underlying drive mounted as a network share, it became read-only, even though the underlying drive is r/w and I am the owner of the sparsebundle file. Re-attaching the drive locally and opening the sparsebundle still results in a read-only FS. I've created a sparseimage and I've been able to write to it ever since, even after several ummounts and remounts, but it seems to be much slower, which is expected. How can I make the sparsebundle writable once again?

I'm on the latest 10.13.

Similar to this.

Thank you
As far as I have understood, macOS allows read-only mounting sparsebundles in almost all situations.

However, when you want to read/write mount a sparsebundle, the underlying filesystem (in this case the network protocol you're using for mounting the wireless drive - for example AFP or SMB) must support F_FULLFSYNC. If your system does not support that the risk of data loss is substantial.

Therefore check if you can use a different protocol, or you can change the settings, mount options or FUSE-driver (if such is used) to allow F_FULLFSYNC.