When rebooting our system, which has / as a md0 RAID1 device, we get:

Unmounting file
systems                                                         
Turning off RAID for md0 md: md0 still
mounted.                                 
/dev/md0: Device or resource
busy                                               
                                                                                
Unmounting proc file
system                                                     
Please stand by while rebooting the
system...                                   
stopping all md
devices.                                                        
marking sb
clean...                                                             
md: updating md0 RAID superblock on
device                                      
sdb3 [events: 0000001a](write) sdb3's sb offset:
8329600                        
sda3 [events: 0000001a](write) sda3's sb offset:
8329600                        
.                                                                               
md0 switched to read-only
mode.                                                 
Restarting system.                                         

Upon reboot, everything seems to mount correctly without any problems, so
I'm wondering if I should be worrying about the above error. My
/etc/raidtab:

raiddev            
/dev/md0                                                    
raid-level                 
1                                                   
nr-raid-disks              
2                                                   
chunk-size                 
64k                                                 
persistent-superblock      
1                                                   
#nr-spare-disks    
0                                                           
    device         
/dev/sda3                                                   
    raid-disk    
0                                                             
    device         
/dev/sdb3                                                   
    raid-disk     1             

Any help appreciated.

Viraj.