I can't able to connet to the database, while connecting i'm receiving the below error:
ERROR: ORA-01034: ORACLE not available
I shutdown the database and restarted it, while during this process i face new error :
ORA-01578: ORACLE data block corrupted (file # 1, block # 2)

Can any one help me to sort this out?

SQL*Plus: Version - Production on Thu Aug 23 15:04:50 2012

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ERROR: ORA-01034: ORACLE not available
ORA-07318: smsget: open error when opening sgadef.dbf file.
SunOS Error: 2: No such file or directory