On Wed, 08 Nov 2017, Thomas Schmitt wrote: > > dd: failed to open '/dev/sdd': Read-only file system > > What the hell ... ? > Why does dd talk of filesystems ? I'd understand if it said "Permission > denied". The superuser isn't what he used to be.
Because the only error number usable for "this thing is read-only" in POSIX is EROFS, so that's what a read-only block device reports. Never mind "EROFS" reads like something that would be used to deny access to a digital porn stash instead... Anyway, if this is a pendrive or some other flash-based media, it most often means it is in the fail-safe last-resort mode (switched to read-only access so that you can try to salvage some data off it). Of course, you could also be that one has moved by accident that minuscle "tab" in some SD cards (and SD-to-micro-SD adapters) to the write-protect position... -- Henrique Holschuh
