io is not running while farebooting node1

[dgkedkwekw]

Hi

i have 2 node cluster.when i am runnig i/o from client side..and i am rebooting node1 .......after 2 to 3 sec...failover is happening to the other node2,but my i/o is not running..its says  permission denied ......i have tried copy and dd also in both the cases i/o is not running while farebooting node1.please help...i have check all the permission everything is ok.if i am not running i/o then its working fine.