RE: ataraid in 2.6.?

[Nicklas Bondesson]

How do you set this (device mapping) up using the 2.6 kernel. I like the
ease of using ataraid in 2.4.x. Why not have both alternatives as options
(both ataraid and devicemapper)? Also have anyone of you looked at the patch
from Walt H that he sent in yesterday? I have to use this after replacing my
old hard drives (Maxtor 30GB) with WDC 80GB. The patch is attached. 

/Nicke

-----Original Message-----
From: linux-kernel-owner@xxxxxxxxxxxxxxx
[mailto:linux-kernel-owner@xxxxxxxxxxxxxxx] On Behalf Of Christophe Saout
Sent: den 29 december 2003 18:08
To: arjanv@xxxxxxxxxx
Cc: Nicklas Bondesson; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: ataraid in 2.6.?

Am Mo, den 29.12.2003 schrieb Arjan van de Ven um 10:49:
>
> the plan is to have a userspace device mapper app take it's place.
> As for the timeframe; I'm looking at it but the userspace device 
> mapper code is still a bit of a mystory to me right now.

It is? I think it's kind of simple (probably, if you know what's going on
;)). Which interface are you looking it?

I'm just looking at the ataraid code. Is my assumption correct, that it
simply interleaves sectors between two harddisks? Even sector number -> hd1,
odd number -> hd2?

Using the simple dmsetup tool one could try something like:

echo 0 $(expr $(blockdev --getsize /dev/<HD1>) \* 2) stripe 2 1 /dev/<HD1> 0
/dev/<HD2> 0 | dmsetup create ataraid

Where <HD1> and <HD2> should of course be replaced by the raw disks.

If everything is correct a device /dev/mapper/ataraid should be created.

Using libdevmapper something like:
dm_task_create(DM_DEVICE_CREATE)
dm_task_task_set_name (required)
dm_task_set_uuid (optional)
dm_task_add_target (only once in this case, contains the stripe target)
dm_task_set_ro (if readonly) dm_task_set_major / _minor (if you don't want a
dynamically allocated) dm_task_run

--
Christophe Saout <christophe@xxxxxxxx>
Please avoid sending me Word or PowerPoint attachments.
See http://www.fsf.org/philosophy/no-word-attachments.html

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Attachment: pdcraid.patch
Description: Binary data