Hi Chris, On Sat, Mar 29, 2014 at 02:07:46AM +1300, Chris Bannister wrote: > How do you know when to use /dev/sd0a vs /dev/rsd0a
It depends on whether you need character-oriented or block-oriented access. For example, you usually mount a disk in the block-device way, but OTOH it helps to write a disklabel to a raw device. Some man pages will you which access method is preferred, or at least which methods are available. On Sat, Mar 29, 2014 at 02:07:46AM +1300, Chris Bannister wrote: > Found this, http://www.openbsd.org/faq/faq14.html > "... The device files would be /dev/sd0a for the block device, > /dev/rsd0a would be the device file for the "raw" (character) device." > > Is that like /dev/sda1 vs /dev/sda in Linux, where /dev/sda represents > the whole device, and /dev/sda1 represents the first partition on > /dev/sda? The answer is no. Actually, you answered your own question. The NetBSD/OpenBSD "r" convention has nothing to do with partitions -- it means, as you correctly mention, that you want to access some device (and/or a particular partition) in a character-oriented way (1 byte at a time), rather than a block-oriented way (many bytes at a time). For example, in NetBSD and OpenBSD you refer to the second partition of the first sd(4) raw device like this: /dev/rsd0b ("0" == 1st device, "b" == 2nd partition). -Christian
