Be sure to be on different switchs !

It's good to have more than one fcs adapter... but it's better to be sure they are connected on different switchs !
Each id is different, if it is on another switch

in this case we have two  adapters (or 2 ports on the same card):

root:/# lsdev -c adapter | grep fcs
fcs0   Available 30-T1 Virtual Fibre Channel Client Adapter
fcs1   Available 31-T1 Virtual Fibre Channel Client Adapter

but on the same vio server ! ....

root:/# echo "vfcs" | kdb
           START              END
0000000000001000 0000000005770000 start+000FD8
F00000002FF47600 F00000002FFDF9C0 __ublock+000000
000000002FF22FF4 000000002FF22FF8 environ+000000
000000002FF22FF8 000000002FF22FFC errno+000000
F1000F0A00000000 F1000F0A10000000 pvproc+000000
F1000F0A10000000 F1000F0A18000000 pvthread+000000
read vscsi_scsi_ptrs OK, ptr = 0xF1000000C01A9380
(0)> vfcs
NAME      ADDRESS             STATE   HOST      HOST_ADAP  OPENED NUM_ACTIVE
fcs0      0xF10001019999A000  0x0008  vioprex1vfchost2  0x01    0x0000
fcs1      0xF10001019A3AC000  0x0008  vioprex1vfchost3  0x01    0x0000and on the same swicth !!!


root:/# lsattr -El fscsi0
attach       switch    How this adapter is CONNECTED         False
dyntrk       yes       Dynamic Tracking of FC Devices        True
fc_err_recov fast_fail FC Fabric Event Error RECOVERY Policy True
scsi_id      0x340206  Adapter SCSI ID                       False
sw_fc_class  3         FC Class for Fabric                   True
root:/# lsattr -El fscsi1
attach       switch    How this adapter is CONNECTED         False
dyntrk       yes       Dynamic Tracking of FC Devices        True
fc_err_recov fast_fail FC Fabric Event Error RECOVERY Policy True
scsi_id      0x340501  Adapter SCSI ID                       False
sw_fc_class  3         FC Class for Fabric                   True


this other partition is ok :

# lsattr -El fscsi0
attach       switch    How this adapter is CONNECTED         False
dyntrk       yes       Dynamic Tracking of FC Devices        True
fc_err_recov fast_fail FC Fabric Event Error RECOVERY Policy True
scsi_id      0x1db40   Adapter SCSI ID                       False
sw_fc_class  3         FC Class for Fabric                   True
# lsattr -El fscsi1
attach       switch    How this adapter is CONNECTED         False
dyntrk       yes       Dynamic Tracking of FC Devices        True
fc_err_recov fast_fail FC Fabric Event Error RECOVERY Policy True
scsi_id      0x20db40  Adapter SCSI ID                       False
sw_fc_class  3         FC Class for Fabric                   True

Merci Patrice, pour l'info !