Date: Sat, 24 Aug 2002 10:29:19 +0200 From: Steve O'Hara-Smith <steve@sohara.org> To: "Andrew P. Lentvorski" <bsder@mail.allcaps.org> Cc: freebsd-stable@freebsd.org Subject: Re: Using atacontrol for RAID ... Message-ID: <20020824102919.49d9951a.steve@sohara.org> In-Reply-To: <20020822151955.Q36782-100000@mail.allcaps.org> References: <20020822151955.Q36782-100000@mail.allcaps.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 22 Aug 2002 15:37:48 -0700 (PDT)
"Andrew P. Lentvorski" <bsder@mail.allcaps.org> wrote:
APL> Okay, so I'm trying to use atacontrol to create a RAID system. I
APL> don't have a motherboard with a RAID controller. I do have a
APL> motherboard (Asus A7V133) which has 4 IDE ports.
If I get any of this wrong someone please correct me :)
APL> What is the magic command to rebuild a failed RAID array?
dd - (AIUI) see below for details.
APL> Here's my procedure:
APL>
APL> 1) I do a clean install of FreeBSD from the 4.6 CD's
On to ad0 I presume.
APL> 2) atacontrol RAID1 ad0 ad2
APL> The system claims that ar0 is good to go
Yep - but with no valid content :(
A dd if=/dev/ad0 of=/dev/ad2 before putting the RAID1 together
would (I think) have resulted in a bootable ar0.
APL> Okay, now comes the fun parts:
APL>
APL> Lets simulate a disk failure -- take 1:
What a good idea.
APL> A) Shut down machine
APL> B) Disconnect drive ad2
APL> C) Power on machine
APL> D) System powers up and works claiming a degraded array. Fine.
APL> E) Shut machine down.
APL> F) Reconnect original drive to ad2 with the expectation of a rebuild
Unfortunately no rebuild without hardware RAID :( It is a pity
that the RAID wasn't degraded. It seems that the admin must ensure
mirror integrity when constructing, or rebuilding the array. Not too
onerous, but it helps to know :)
My guess is the panic was caused because the swap partition
contents differed.
Cloning ad0 to ad2 with dd seems to be the only repair method.
APL> F) Reconnect sparkly new drive to ad2 with the expectation of a
APL> rebuild G) Power up machine
APL> H) Machine powers up with ad0 in a degraded ar0. Fine. New ad2 is
APL> also
It would IMHO have been nice if this had happened in "take 1"
when your reconnected the drive - I suppose it is difficult to achieve.
APL> So, what do I do now?
dd if=/dev/ad0 of=/dev/ad2
(you may want to add a bs=1024k to that line)
PS: Let us know if it works - I've been planning on playing
soonish.
--
C:>WIN | Directable Mirrors
The computer obeys and wins. |A Better Way To Focus The Sun
You lose and Bill collects. | licenses available - see:
| http://www.sohara.org/
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020824102919.49d9951a.steve>