Gentoo Archives: gentoo-user

From: Fast Turtle <fturtle@×××××.com>
To: Gentoo User List <gentoo-user@l.g.o>
Subject: Re: [gentoo-user] Who/what names hard drives /dev/sda, /dev/sdb, etc
Date: Fri, 07 Jun 2013 05:31:35
In Reply to: [gentoo-user] Who/what names hard drives /dev/sda, /dev/sdb, etc by Chris Stankevitz
1 The /dev/ (h/s)da is actually from the kernel itself with the (H) being
2 deprecated as it's from the old ide/pata setup (hda was always ide 0-0
3 (same setup grub uses) designated as master) while 0-1 was the slave. 1-0
4 would then be hdb while 0-1 would have been hdc with hdd being 1-1 (the
5 last two being slaves).
7 The (S) designation is due to the change in the kernel hardware subsystem,
8 where they started moving all of the various drive types to a single,
9 simpler uniform setup based around the scsi code. It's also why when
10 manually configuring a kernel, if you enable usb storage (flash/sd/mmc)
11 you're told you need scsi support in the help.
13 All of these changes have been implemented by the kernel team comprised of
14 Linus Torvald and all of the maintainers for the express purpose of
15 simplifying the code base while reusing as much of the existing code as
16 possible in a far more modular manner - easier to fix/maintain and by
17 becoming more modular, it's easier to add new features to the kernel as
18 they're developed, which is why if you look at the configuration of a 3.4
19 series compared to the 3.8 you see lots of things have and are being moved.
22 On Thu, Jun 6, 2013 at 9:16 PM, Chris Stankevitz
23 <chrisstankevitz@×××××.com>wrote:
25 > Hello,
26 >
27 > Who or what decides to name a hard drive /dev/sda vs /dev/sdb?
28 >
29 > How does it decide what order to enumerate the drives on my computer?
30 >
31 > When in the boot process does is a disk given a name like "/dev/sda"?
32 >
33 > Thank you,
34 >
35 > Chris
36 >
37 >