[Novalug] Old Vs New was: Re: Kernel configuration for opticaldrive.
agrimes at speakeasy.net
Mon Mar 29 10:16:51 EDT 2010
Bryan J Smith wrote:
> Again, today's storage includes:
> - [S]ATA -- Dumb, Serial or Parallel Hardware Block AT Attachment (ATA)
> - SCSI -- Queued, Block Small Computer Systems Interface (SCSI)
> - AHCI -- Queued, Block Serial AT Attachment ("modern" SATA)
<<<<< NEW INFORMATION -- YAY!!! =P
> I think the dead horse has been steadily moving from all the beatings it
> has been taking. ;) This is PC-level stuff. Linux is just trying to
> cope. Between the 2TiB (2.2TB) limitations of legacy BIOS/DOS disk
> labels (aka "Partition Table") and the on-going, "ATA is ATA, SCSI is
> SCSI," people here are just proving why they don't learn.
That just means that the kernel should have these sections in it's
ATA (ide etc...)
Device Protocols (CD-ROM, tape, etc...)
How the code is cross-linked internally is irrelevant.
And, naturally, in /dev there should be separate namespaces for each of
the connectors you listed such that the first device connected to the
first port of any such connector will *ALWAYS*, without fail or
exception, receive the first designation.
In my case, if I own exactly 1 PATA drive, and I connect it to the first
port of the first IDE controller, under no circumstances will it receive
the designation sdb.
Furthermore I am concerned about the designation sdb again because my
SATA controller has two ports, 1 internal and 1 external. I think
hardware-wise, the first port is the internal, and the second is the
internal. Therefore I would expect sda to be not-connected and my SATA
data drive to be sdb. This is not the case. I don't know what the kernel
would do if I actually installed a drive to that external port. Would I
have to rewrite my /etc/fstab again? Obviously the new setup is
profoundly problematic in ways that Bryan refuses to admit.
As to the suggestion that I use uuids, My point on that front is that
uuids (on desktop systems), are a solution to a problem that is entirely
artificial created wholly by the unreliable naming scheme (or rather
lack of a naming scheme) for the block devices.
My point on the dynamically added device front is that only USB lacks
(AFAIK) positional device addressing. -- Ie no port is the "first"
"second", "third" etc... So for namespaces of ATA, AHCI, and SCSI
devices, a naming scheme that numbers devices by the port they are
attached to is entirely practical and unambiguously desirable because it
prevents the user from having to resort to mounting partitions by uuid
which can't be predicted ahead of time and are extremely cumbersome (and
error prone!) to work with from the command line which doesn't have
cut-and-paste. (Naturally, the drives must be set up before x-'doze can
DO NOT USE OBAMACARE.
DO NOT BUY OBAMACARE.
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