info about hdds in raid

[Christopher Chan]

>> How can I tell wich HDD to swap, when the "cat
>> /proc/mdstat" says one HDD of the RAID1 array has
>> died?
>>
>>
>>     
> I read this with interest but I don't see where the commands would show which drive has failed.  Is is something obvious to you that isn't to me, someone who has never used any raid setup. I certainly would like to know as I have a computer in my lan with 2 HDDs that someday when I'm feeling reckless may try to set up a raid system.
> Leonard Chatagnier
> lenc5570 at sbcglobal.net
>
>   
 cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] 
[raid4] [raid10]
md1 : active raid1 sda2[0] sdb2[1]
      243954944 blocks [2/2] [UU]
     
md0 : active raid1 sda1[0] sdb1[1]
      240832 blocks [2/2] [UU]
     
unused devices: <none>



The UU in square brackets tell us that all disks are Up. If you see a 
'_', then that disk/partition is down/dropped. So if I had

md0 : active raid1 sda1[0] sdb1[1]
      240832 blocks [2/2] [U_]


then that means that sdb1 needs some work done.