Seen on the SLETC Wyse when using a usb stick. NTFS on the stick: cp foo ~/thindrives/usbstorage-0 => EIO cp foo ~/thindrives/usbstorage-0 => EPERM echo foo > ~/thindrives/usbstorage-0/bar => OK echo foo > ~/thindrives/usbstorage-0/bar => EPERM i.e. the behaviour changes depending on if the target file exists or not. With FAT on the stick it is only cp that fails, when the target doesn't exist: cp foo ~/thindrives/usbstorage-0 => EPERM cp foo ~/thindrives/usbstorage-0 => OK Reminds me a bit of bug 4592. No problems accessing the files locally on the terminal.