All Disk are failing in 3300 JBOD

Dear Gurus,

We have v440 server which is connected with 2 JBODs and VXvm running on it.
Each JBOD has 12 disks in it.all of a sudden all disk are showing as
failing state,apart from 2 disk , 1 is completely failed ,

I had replaced the faulty disk now.Would like to know what is the cause for
this issue.

Any Guess??

Soalris 10 , vxvm5.0

smipsdevel01 # vxdisk list

DEVICE TYPE DISK GROUP STATUS

c1t0d0s2 auto:sliced rootdg01 rootdg online nohotuse

c1t1d0s2 auto:sliced rootdg02 rootdg online nohotuse

c2t0d0s2 auto:cdsdisk datadg01 datadg online

c2t1d0s2 auto:cdsdisk datadg06 datadg online

c2t2d0s2 auto:cdsdisk datadg07 datadg online

c2t3d0s2 auto:cdsdisk datadg08 datadg online

c2t4d0s2 auto:cdsdisk datadg09 datadg online

c2t5d0s2 auto:cdsdisk datadg10 datadg online

c2t8d0s2 auto:cdsdisk datadg11 datadg online

c2t9d0s2 auto:cdsdisk datadg12 datadg online spare

c2t10d0s2 auto:cdsdisk datadg02 datadg online

c2t11d0s2 auto:cdsdisk datadg03 datadg online

c2t12d0s2 auto:cdsdisk datadg04 datadg online

c2t13d0s2 auto:cdsdisk datadg05 datadg online

c4t0d0s2 auto:cdsdisk datadg13 datadg online

c4t1d0s2 auto:cdsdisk datadg18 datadg online failing

c4t2d0s2 auto:cdsdisk datadg19 datadg online failing

c4t3d0s2 auto:cdsdisk datadg20 datadg online failing

c4t4d0s2 auto:cdsdisk datadg21 datadg online failing

c4t5d0s2 auto:cdsdisk datadg22 datadg online failing

c4t8d0s2 auto:cdsdisk datadg23 datadg online

c4t9d0s2 auto:cdsdisk datadg24 datadg online failing

c4t10d0s2 auto:cdsdisk datadg14 datadg online failing

c4t11d0s2 auto:cdsdisk datadg15 datadg online

c4t12d0s2 auto:cdsdisk datadg16 datadg online failing

c4t13d0s2 auto:cdsdisk datadg17 datadg online spare failing