3 ms·

cp file.iso /dev/sda

• ewy1 20d ago
  this works great but in my experience sometimes you should add && sync not sure why it's necessary only sometimes!
  • rascul 20d ago
    The kernel has a cache used for block devices. If you want to be more targeted: blockdev --flushbufs /dev/sda
• WhyNotHugo 20d ago
  This isn't portable though, it's a GNU-specific "smart" things. Elsewhere, this overwrites the target device file.
  • jasomill 20d ago
    Redirection doesn't overwrite device files, so cat foo.img > /dev/sda works and should be portable. No control over the buffer size, though.
    • LtWorf 19d ago
      And no printing of progress either.
  • akdev1l 20d ago
    How exactly is cp not portable? Whatever behaviour you’re describing is not how POSIX mandates cp to work. In fact you can do this with busybox too. cp will open("/dev/sda", O_WRONLY | O_TRUNC) and simply start writing to that file descriptor.
    • deleted 20d ago
      [deleted]