[mythtv-users] OT Help: mdadm segfault

[George Mari]

Steve MacLaren wrote:
> On 9/17/07, George Mari <george_mythusers at mari1938.org> wrote:
>>
>>
>> Please post the output of each of the following:
>>
>> mdadm --examine /dev/sda1
>> mdadm --examine /dev/sdb1
>> mdadm --examine /dev/sdc1
>> mdadm --examine /dev/sdd1
>>
>> I'm guessing that /dev/sda1 will report no valid info or some such, but
>> if the other 3 drives all have same/similar values for the 'events'
>> field, you should be able to recover.
> 
> 
> Here's what I get:
> 
> /dev/sda1:
>           Magic : a92b4efc
>         Version : 00.90.00
>            UUID : bc7a4d90:bd286a91:c109596b:d7e29b7e
>   Creation Time : Mon May  7 21:31:55 2007
>      Raid Level : raid5
>     Device Size : 488383872 (465.76 GiB 500.11 GB)
>      Array Size : 1465151616 (1397.28 GiB 1500.32 GB)
>    Raid Devices : 4
>   Total Devices : 4
> Preferred Minor : 0
> 
>     Update Time : Wed Sep 12 15:58:54 2007
>           State : active
>  Active Devices : 4
> Working Devices : 4
>  Failed Devices : 0
>   Spare Devices : 0
>        Checksum : 66008fbc - correct
>          Events : 0.161

Do all the other drives have the same value for this field above, 
"Events"? (Are they all 0.161?)  If all four are the same, then the data 
on your array is intact.  If at least three of the four are the same, 
you will be able to re-build the array from the three good drives.  The 
one that has a different value got kicked out of the array.

> 
>          Layout : left-symmetric
>      Chunk Size : 128K
> 
>       Number   Major   Minor   RaidDevice State
> this     0       8        1        0      active sync   /dev/sda1
> 
>    0     0       8        1        0      active sync   /dev/sda1
>    1     1       8       17        1      active sync   /dev/sdb1
>    2     2       8       33        2      active sync   /dev/sdc1
>    3     3       8       49        3      active sync   /dev/sdd1
> 

So what this above says is, "according to the superblock info on *this* 
drive, the state of each drive in the array is 'active sync'".

When you do mdadm --examine /dev/sd*1 on each of the other three drives, 
if they all report the same information (all drives 'active sync') your 
array is fine.

If this is the case, I agree with the other poster that you may have a 
hardware problem elsewhere, such as power supply.

Of course, even if the array does have a problem with one drive, it 
still could be that something like a power supply problem could be 
causing your array to fail.