Support read-only namespaces: zdbfs can connect read-only (write-protected) namespace to serve a read-only filesystem. There is no need to add -o ro option to get the filesystem working but writing on the filesystem will cause Input/output error (this won't have any impact). To avoid this, if you know you're connecting a read-only backend, just add -o ro and filesystem will be mounted in read-only.
In addition, this release improve autons feature with zdb in mixed-mode to force sequential mode.