Description of problem:

Created a mirror:
[root@link-13 ~]# lvs -a -o+devices
  LV                    VG        Attr   LSize   Origin Snap%  Move Log        
    Copy%  Devices                                      
  mirror_vol            mirror_vg mwi-ao 100.00G                   
mirror_vol_mlog   0.00 mirror_vol_mimage_0(0),mirror_vol_mimage_1(0)
  [mirror_vol_mimage_0] mirror_vg iwi-ao 100.00G                               
           /dev/sdc1(0)                                 
  [mirror_vol_mimage_1] mirror_vg iwi-ao 100.00G                               
           /dev/sdb1(0)                                 
  [mirror_vol_mlog]     mirror_vg lwi-ao   4.00M                               
           /dev/sdb2(0)

Started IO from all nodes in a four node cluster before the mirror was in sync.
                               
Observed this in the logs:
Jul 20 21:11:50 link-13 kernel: device-mapper: Reason :: 1
Jul 20 21:11:50 link-13 kernel: device-mapper: unable to get server (1) to mark
region (1713)
Jul 20 21:11:50 link-13 kernel: device-mapper: Reason :: 1
Jul 20 21:11:50 link-13 kernel: device-mapper: unable to get server (1) to mark
region (1713)
Jul 20 21:11:50 link-13 kernel: device-mapper: Reason :: 1
Jul 20 21:11:50 link-13 kernel: device-mapper: sync_count (204940) >
region_count (204800) - (mjIFcdjY)!
Jul 20 21:12:02 link-13 last message repeated 954 times
Jul 20 21:12:02 link-13 kernel: device-mapper: sync_count (204941) >
region_count (204800) - (mjIFcdjY)!
Jul 20 21:12:02 link-13 last message repeated 34 times
Jul 20 21:12:02 link-13 kernel: device-mapper: sync_count (204942) >
region_count (204800) - (mjIFcdjY)!
Jul 20 21:12:05 link-13 last message repeated 287 times
Jul 20 21:12:05 link-13 kernel: device-mapper: an error occured on the server
while processing our request
Jul 20 21:12:05 link-13 kernel: device-mapper: sync_count (204942) >
region_count (204800) - (mjIFcdjY)!
Jul 20 21:12:37 link-13 last message repeated 3068 times
Jul 20 21:12:46 link-13 last message repeated 706 times

The IO is still running a day later, and the logs are still showing the message.

IO run was: 
b_iogen -o -m random -s read,write,readv,writev -t 1000b -T 100000b -d
/dev/mirror_vg/mirror_vol | b_doio 

Translated that states:  Do overlapping read(), write(), readv(), and writev().
 Stride randomly on device. Generate each request with a minimum transfer of
1000 blocks, and a maximum transfer of 100000 blocks.
 


Version-Release number of selected component (if applicable):

lvm2-cluster-2.02.06-5.0.RHEL4
lvm2-2.02.06-5.0.RHEL4
device-mapper-1.02.07-4.0.RHEL4
cmirror-kernel-2.6.9-10.2