Dude wrote:There are raw devices and raw devices. The one means defining a character device as a raw device for a block device (deprecated).
The use of raw disk devices since RHEL 5 and derivatives has been depreciated.
Dude wrote:It was a very basic 386/486 kernel written with AT harddrive support, and without any illusions of it being more than a simple Open Source o/s for mucking around... (see Linus's first posting on what was to become the Linux kernel).
As far as I know, Linux was initially designed for low-end and cheap computer hardware.
A lot has changed since, but the initial design concept of Linux that the kernel should cache and schedule/group all I/O to optimize performance remains. Raw device access makes sense for applications and hardware that deal with I/O on it's own, usually more expensive devices, at least in the past.Not really expensive devices - SATA and SAS devices are quite cheap compared to higher-end disk storage (like SSDs). And these can be RAID'ed just fine using ASM as raw devices.