Fixing a Linux RAID 1 software mirror

[Gregory Gulik]

I don't know if this helps or not but I'm having a very similar problem 
with RAID on a server still running Red Hat 9.  lsraid shows partitions 
going away all the time but if I check again a day or two later they are 
fine again.  I was never able to find any reason for that but it's been 
over a year now and still no data loss.  It does make me VERY nervous 
every time it happens.


Michael Mansour wrote:
> 
>> Hi,
>>
>> I've just noticed I have the following issue on my
>> /home (/dev/md5) software RAID mirror:
>>
>> [root at gazelle root]# lsraid -a /dev/md5
>> [dev   9,   5] /dev/md5        6A995494.6BAA9433.BC09B08A.778BCE84 online
>> [dev   ?,   ?] (unknown)       00000000.00000000.00000000.00000000 
>> missing
>> [dev  34,   8] /dev/hdg8       6A995494.6BAA9433.BC09B08A.778BCE84 good
>>
>> With the raidtab showing:
>>
>> raiddev             /dev/md5
>> raid-level                  1
>> nr-raid-disks               2
>> chunk-size                  64
>> persistent-superblock       1
>> nr-spare-disks              0
>>    device          /dev/hde8
>>    raid-disk     0
>>    device          /dev/hdg8
>>    raid-disk     1
>>
>> and the /proc/mdstat shows:
>>
>> md5 : active raid1 hdg8[1]
>>      20972736 blocks [2/1] [_U]
>>
>> As /dev/md5 is my /home directory, I don't want to
>> lose any data. How can I fix this to get /dev/hde8
>> into the md5 raidset without losing my data?

-- 
Greg Gulik                                 http://www.gulik.org/greg/
greg @ gulik.org