Re:

[Phil Turmel <philip@turmel.org>]

On 06/10/2011 04:26 PM, Dragon wrote:
> "No, it must be "Used Device Size" * 11 = 16116523456.  Try it without the 'k'."
> -> was better:

[...]

> ->fsck -n /dev/md0, was ok
> ->now:mdadm /dev/md0 --grow -n 12 --backup-file=/reshape.bak
> ->and after that, how become the disk out of the raid?

Monitor your background reshape with "cat /proc/mdstat".

When the reshape is complete, the extra disk will be marked "spare".

Then you can use "mdadm --remove".

> at this point i think i take the disk out of the raid, because i need the space of the disk.

Understood, but you are living on the edge.  You have no backup, and only one drive of redundancy.  If one of your drives does fail, the odds of losing the whole array while replacing it is significant.  Your Samsung drives claim a non-recoverable read error rate of 1 per 1x10^15 bits.  Your eleven data disks contain 1.32x10^14 bits, all of which must be read during rebuild.  That means a _13%_ chance of total failure while replacing a failed drive.

I hope your 16T of data is not terribly important to you, or is otherwise replaceable.

> I need another advise of you. While the computer is actualy build with 13 disk and i will become more data in the next month and the limit of power supply connecotors is reached i am looking forward to another solution. one possibility is to build up a better computer with more sata and sas connectors and add further raid-controller-cards. an other idea is to build a kind of cluster or dfs with two and later 3,4... computer. i read something about gluster.org. do you have a tip for me or experience in this?

Unfortunately, no.  Although I skirt the edges in my engineering work, I'm primarily an end-user.  Both personal and work projects have relatively modest needs.  From the engineering side, I do recommend you spend extra on power supplies & UPS.

Phil