Re: Moving mdadm raid volume to new OS install

On Thu, Feb 7, 2013 at 5:13 PM, Sam Martin <sambomartin@gmail.com> wrote:

thanks shane. sorry, just one last thing.

my mdadm.config doesn't contain reference to any devices. is this because it's stored on the raid members?

thanks again,
sam

On 8 February 2013 00:10, Shane Johnson <sdj@rasmussenequipment.com> wrote:

On Thu, Feb 7, 2013 at 5:07 PM, Sam Martin <sambomartin@gmail.com> wrote:

brilliant, not rebuild though, you mean remount / assemble?

On 7 February 2013 23:50, Shane Johnson <sdj@rasmussenequipment.com> wrote:

On Thu, Feb 7, 2013 at 4:46 PM, Sam Martin <sambomartin@gmail.com> wrote:

do you know whether i could move a raid1 vol from 32bit dist to 64bit dist?

On 7 February 2013 23:32, Shane Johnson <sdj@rasmussenequipment.com> wrote:

On Thu, Feb 7, 2013 at 4:23 PM, Sam Martin <sambomartin@gmail.com> wrote:

could it be used without mdadm? i think the suggestion was that if it went wrong the disk could still be used as the "raid" stuff was on the end of the disk?

that right?

On 7 February 2013 22:33, Shane Johnson <sdj@rasmussenequipment.com> wrote:

On Thu, Feb 7, 2013 at 2:42 PM, Sam Martin <sambomartin@gmail.com> wrote:

Hi Pascal,

I'm not sure what top-posting is?
I hope this isn't it!

You mean test whether i can bring the raid vol up by booting into 64bit debian from usb?

i did a mdadm -e on one of the disks in the array

root@HTPC-NAS:~# mdadm -E /dev/sdc1
/dev/sdc1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 25a729b1:71f5193b:6abe8ba9:21e698f5
Name : HTPC-NAS:0 (local to host HTPC-NAS)
Creation Time : Thu Dec 20 12:25:56 2012
Raid Level : raid1
Raid Devices : 2

Avail Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Array Size : 2930133824 (2794.39 GiB 3000.46 GB)
Used Dev Size : 5860267648 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : clean
Device UUID : fe1998ea:8535a654:31083985:d8c560c1

Update Time : Thu Feb 7 09:01:38 2013
Checksum : ad4320a8 - correct
Events : 51

Device Role : Active device 1
Array State : AA ('A' == active, '.' == missing)

I think the 1.2 means it's a no go in terms of running the disk independently of the raid vol.

Thanks
Sam

On Sunday, January 27, 2013 11:10:01 PM UTC, Pascal Hambourg wrote:
> Sam Martin a ï¿œcrit :
>
> > Thanks for reply Pascal.
>
>
>
> Please don't top-post.
>
>
>
> > How would I know?
>
>
>
> mdadm -E /dev/<raid_member> (e.g. /dev/sdc1)
>
> mdadm -D /dev/<raid_device> (e.g. /dev/md0)
>
> cat /proc/mdstat
>
>
>
> > I've just posted a question to original response, do you happen to know the answer?
>
>
>
> There are two questions.
>
> I already replied to the first one. I don't know about the second one,
>
> but I see no reason why the RAID array would not work with a 64-bit
>
> system. If unsure just try it with a 64-bit live system.

>
>
>
>
>
> --
>
> To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
>
> with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
>

> Archive: http://lists.debian.org/5105AF36.60803@plouf.fr.eu.org

--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org

Archive: [🔎] 9bfc076c-457e-45e3-8719-35bc86a0f878@googlegroups.com" target="_blank">http://lists.debian.org/[🔎] 9bfc076c-457e-45e3-8719-35bc86a0f878@googlegroups.com

Your output from mdadm -e on that disk show that it is raid level one which is a mirror so you can run with one disk failed, but there is no redundancy anymore.

--
Shane D. Johnson
IT Administrator
Rasmussen Equipment

Sorry, I don't think so. From my understanding, it is still a member of the raid and would need the mdadm in order to present the volume to the os to see the partition info, Although, I don't know about pulling data of with some sort of disk forensics.

--
Shane D. Johnson
IT Administrator
Rasmussen Equipment

Please use reply all to keep on the list for future reference and the enlightenment of as many people as possible.

Yes, mdadm will rebuild it as long as it supports the version that created the volume.

--
Shane D. Johnson
IT Administrator
Rasmussen Equipment

Yes - reassamble is correct. thanks for the correction.

--
Shane D. Johnson
IT Administrator
Rasmussen Equipment

From my experience you have to manually put it in there. Going from memory, I believe that mdadm -E --scan > /etc/mdadm/mdadm.conf should do the trick. I would do it without the redirect first to make sure you just get the information in the right format. If it's not correct a quick Google search should locate the correct command to get it in there. I read a lot of recommendations that you just add it by hand but the above method worked for me.

Shane

--
Shane D. Johnson

IT Administrator

Rasmussen Equipment