[BlueOnyx:07865] Re: Disk failure and working out exactly which disk

[Jeff Folk]

On Jul 27, 2011, at 7:17 AM, Richard Morgan wrote:
> 
> Hi... hope someone can help as I'm a bit stuck.
>  
> We've got a BX server with software RAID and it's reporting a single disk failure both in the GUI and with the following:
>  
> [admin at s1 ~]$ cat /proc/mdstat
>  
> Personalities : [raid1]
>  
> md0 : active raid1 sdb1[2](F) sda1[0]
>  
>       256896 blocks [2/1] [U_]
>      
>  
> md1 : active raid1 sdb2[2](F) sda2[0]
>  
>       976502912 blocks [2/1] [U_]
>  
> unused devices: <none>
>  
> The guys in the data centre are great and will change a disk for me, but I need to know if it's SATA0 or SATA1 for the controller.
>  
> What is the command to work this out?  U_ implies 0 is fine, but 1 is failing - howover I don't want to assume anything.
>  
> Many thanks indeed.
>  
> Richard

sdb1 is flagged as failed here with "(F)" -- md0 : active raid1 sdb1[2](F) sda1[0]
                                                                        ^
sda is usually the first SATA port, sdb the second, etc...

You can also type (as root):

mdadm --detail /dev/md0

to see the detail. At the bottom of the output will be a drive list for your array showing components and status (this is from my RAID5 array):

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
       2       8       33        2      active sync   /dev/sdc1

Where one of the drives will be listed as NOT "active sync"

I'm really curious as to whether BlueOnyx will automatically rebuild the array when the drive is replaced, or if some manual wrangling with mdadm commands will be required... And yours is a simple RAID 1. I'm wondering if I did the right thing by using RAID 1+0? I'm thinking that maybe I should have used RAID 5 with one spare disk on my 4 disk setup. Well... I'm crossing my fingers that I don't have to deal with it, and that the Scientific Linux based BO is quickly forthcomong. Wordpress users are stuck in upgrades until we can have a more recent version of php.

Regards;
Jeff