11.2.0.3 cluster nodes rebooted

Dear ExpertsNeed your expert advise. We're running 2-node 11.2.0.3 cluster on aix 6.1. Last week both nodes rebooted at the same time. In cluster logs I found following errors :

************************************************* log **************************************************************************

CRS-1615:No I/O has completed after 50% of the maximum interval. Voting file /vote/vote1 will be considered not functional in 299658 milliseconds

CRS-1614:No I/O has completed after 75% of the maximum interval. Voting file /vote/vote1 will be considered not functional in 149268 milliseconds

CRS-1613:No I/O has completed after 90% of the maximum interval. Voting file /vote/vote1 will be considered not functional in 59966 milliseconds

2013-07-13 09:54:33.015

[cssd(18088110)]CRS-1604:CSSD voting file is offline: /vote/vote1; details at (:CSSNM00058:) in /u02/app/11.2.0/grid/log/hq07adnricdb01/cssd/ocssd.log.