[GTALUG] Raid 10 repair question

[Lennart Sorensen]

On Thu, Feb 19, 2015 at 06:17:57AM -0600, o1bigtenor wrote:
> Sorry for a slow response but life intervened!
> 
> On Tue, Feb 17, 2015 at 5:07 PM, Digimer <lists at alteeve.ca> wrote:
> 
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> > On 17/02/15 06:04 PM, o1bigtenor wrote:
> > > Now I used gdisk to set things up so likely that is where I will
> > > need to start - - - hmmmmmmmmmmm.
> > >
> > > Has anyone done anything like this in the somewhat recent past?
> > >
> > > (Wondering if when disk is partitioned that mdadm will happily
> > > absorb that disk into the array. Likely will need another reboot
> > > too!)
> > >
> > > Dee
> >
> > I use parted or fdisk, I am not familiar with other tools. In the end,
> > what matters is that the partition(s) on the new drive match (equal
> > size or larger) the existing partitions.
> >
> 
> The drive has not yet been partitioned. The disks (in the array) were
> partitioned to be just one large partition (whole disk).
> 
> >
> > You will then have to tell mdadm to use the new partitions. It will
> > not "just use them".
> >
> > As Lennart asked; Show us the output of 'cat /proc/mdstat'.
> 
> 
> # cat /proc/mdstat
> Personalities : [raid10]
> md0 : active raid10 sdc1[0] sda1[3] sde1[1]
>       1953518592 blocks super 1.2 512K chunks 2 near-copies [4/3] [UU_U]
> 
> unused devices: <none>

Well once you have partitioned the new disk you should be able to just do:

mdadm --add /dev/md0 /dev/sdX1 (whatever X is for the new drive).

Then /proc/mdstat should show it rebuilding the raid.

-- 
Len Sorensen