Re: Looking for the best way to do this

[maurice <mhilarius@gmail.com>]

On 6/24/2011 10:59 AM, Iordan Iordanov wrote:
>
> On 06/24/11 12:35, maurice wrote:
>> Set aside (disconnect) 1 of the existing 2 disks.
>> Boot from emergency recovery media, making sure the md version is
>> relatively current ( newer than 3.0 ?)
>>
>> Create the R10 with the other 2 disks ( 1 old and 1 new) with 1 of the 3
>> disks missing.
>> I think I have to wipe the superblock on the disk that was formerly part
>> of the RAID1 set.
>
> I think your procedure can be made less risky by making a R10, with 
> layout f3 with *two* missing disks. Since there are *3* copies in the 
> R10, there is no problem with having just one "real" disk and two 
> missing ones. This way, you don't have to live with just one of the R1 
> disks and hope it doesn't go bad during the copy operation.
>
> Then, you copy the data from your old R1 to your new R10 with the two 
> missing disks. When the data is copied over, you can remove *one* of 
> the disks from the R1, zero the superblock, and add it to the R10. 
> When the rebuild is complete, and only then, zero the superblock of 
> your last R1 disk, and add it to the R10.
>
> With this mod, your data never really lost redundancy during the 
> entire procedure (except when you remove the first disk from the R1 
> and move it to the R10, but instead of redundancy, you have 2 copies - 
> one on the R10 and one on the R1 at that point, so it's still 
> redundant in a way).
>
> Whether or not you use this revised procedure, write yourself a 
> step-by-step guide with all the commands (a TO-DO list), and if you 
> want, you can share it with the list if you're not confident.
>

Thanks, this makes really good sense, and sounds VERY safe.

As for the "TO-DO list" or "recipe" I still lack the skills to produce 
the syntax.


-- 
Cheers,
Maurice Hilarius
eMail: /mhilarius@gmail.com/