mdadm and fsck

[Joey L <mjh2000@gmail.com>]

I have a broken raid1 drive set - i was able to fix 1 but the other raid still has issues.

i have gone through the tutorials online to bring it back online but still unable to bring it back.

Do i have to run fsck on the individual member drives ???

my /proc/mdstat looks like:

Personalities : [raid1]

md1 : active raid1 sdc1[0] sdd1[1](S)

      976758841 blocks super 1.2 [2/1] [U_]

md0 : active raid1 sda1[2] sdb1[1]

      972654456 blocks super 1.2 [2/1] [_U]

      [==========>..........]  recovery = 50.7% (493690944/972654456) finish=416.5min speed=19162K/sec

my fstab is :

# <file system> <mount point>   <type>  <options>       <dump>  <pass>

proc            /proc           proc    defaults        0       0

# / was on /dev/md0 during installation

UUID=611258bc-4ace-4779-b44d-73ba1949f7db /               ext4    errors=remount-ro 0       1

# swap was on /dev/md1 during installation

UUID=f9dc126d-9593-475a-ab0e-b4126146d885 none            swap    sw              0       0

/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto     0       0

/dev/fd0        /media/floppy0  auto    rw,user,noauto  0       0

/dev/md1        /mnt/raid  ext4 rw        0       1

my questions is :

1. how can i bring it back online.

2. what is the (S) mean ?

3. how do i run fsck or other utility on ext4 filesystem ?

4. do i run it on the raid1 device /dev/md0 or on the individual devices /dev/sda and /devsdb

thanks

mjh