Generating Apache SSL Self-Signed Certificate

1. Full text information:
   
   # openssl x509 -text -in server.crt

2. Issuer of the certificate:
   
   # openssl x509 -noout -in server.crt -issuer

3. Issued to:
   
   # openssl x509 -noout -in server.crt -subject

4. Valid dates:
   
   # openssl x509 -noout -in server.crt -dates

5. All of the above:
   
   # openssl x509 -noout -in server.crt -issuer -subject -dates

6. Hash value:
   
   # openssl x509 -noout -in server.crt -hash

7. MD5 fingerprint:
   
   # openssl x509 -noout -in server.crt -fingerprint

After generating a renewed self-signed ssl cert, I got the below message:

You have received an invalid certificate...
Your certificate contains the same serial number as another
certificate issued by the certificate authority. 
Please get a new certificate containing a unique serial number.

With some digging, found that a new serial number can be set as below.

man x509 for more info.