oracle database corrupt block recovery

Error:

Corrupt block relative dba: 0x1a0975d9 (file 104, block 619993)
Bad check value found during user buffer read
Data in bad block:
 type: 6 format: 2 rdba: 0x1a0975d9
 last change scn: 0x0726.9a3a3fc5 seq: 0x1 flg: 0x06
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x3fc50601
 check value in block header: 0x287e
 computed block checksum: 0xfe81
Reread of rdba: 0x1a0975d9 (file 104, block 619993) found same corrupted data
Tue Feb 18 20:17:59 IST 2014
Corrupt Block Found
         TSN = 47, TSNAME = EVENT_TAB
         RFN = 104, BLK = 619993, RDBA = 436827609
         OBJN = 141322, OBJD = 141322, OBJECT = EVENT_PK, SUBOBJECT =
         SEGMENT OWNER = EVA_ADMIN, SEGMENT TYPE = Index Segment


Background:

ORA-15063: ASM discovered an insufficient number of disks for diskgroup

Error:

ERROR: diskgroup DG02 was not mounted
ORA-15032: not all alterations performed
ORA-15017: diskgroup "DG02" cannot be mounted
ORA-15063: ASM discovered an insufficient number of disks for diskgroup "DG02"
ORA-15080: synchronous I/O operation to a disk failed

ORA-27061: waiting for async I/Os failed
Linux-x86_64 Error: 5: Input/output error
Additional information: -1
Additional information: 4096
WARNING: Read Failed. group:0 disk:0 AU:0 offset:0 size:4096
ERROR: no read quorum in group: required 2, found 0 disks

ERROR: -9(Error 27061, OS Error (Linux-x86_64 Error: 5: Input/output error

ORA-01031: insufficient privileges

Error:

ORA-01031: insufficient privileges

When: 

While compiling a procedure/package/function

Solution: