I configured software raid 1 on two same size HDD, but data is not replicated on another HDD. ?

what can be the issue ?

mdadm --detail /dev/md??

cat /proc/mdstat

What do they show?

mdadm --detail /dev/md1
/dev/md1:
Version : 00.90.03
Creation Time : Mon Dec 3 19:07:09 2007
Raid Level : raid1
Array Size : 241047168 (229.88 GiB 246.83 GB)
Device Size : 241047168 (229.88 GiB 246.83 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 1
Persistence : Superblock is persistent

Update Time : Thu May 8 17:39:04 2008
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0

UUID : 858e282f:037c54cf:7a530e64:56ff3dd9
Events : 0.2532854

Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 0 0 1 removed

[root@localhost ~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb2[1] sda2[0]
3068288 blocks [2/2] [UU]

md1 : active raid1 sda1[0]
241047168 blocks [2/1] [U_]

unused devices: <none>

Pls. help

wanted expert to comment on above case...