netstat -anop | grep 80
First look at the n free.
Look at the N again.
We found that in the local address column, the host address column, if there is no n option, the corresponding domain name of the socket will be resolved out, if the N option is added, then it will not show, that is, the function of forbidding domain name resolution, which helps to improve query speed, because it reduces the number of pairs of.Host domain name query.
View disk information:
This is because Hadoop has been formatted many times using Hadoop namenode-format format, resulting in inconsistent space IDs