Create shortcuts for frequently accessed servers

Life is too short, that’s why it’s mandatory to use shortcuts… Instead of typing frequently used ssh client options such as port, user, hostname, identity-file and so on, you can save that information in sshd config file and then access it with defined alias.

  • System wide config file location is /etc/ssh/ssh_config
  • User specific config file location is ~/.ssh/config same as $HOME/.ssh/config

Instead of connecting to the server everytime using the following command:

# ssh root@ -i ~/.ssh/my_id_rsa

Save the following entries in ~/.ssh/config file:

# vim ~/.ssh/config
Host my_db
IdentityFile ~/.ssh/my_id_rsa
User root

And connect to the server using this simple way:

# ssh my_db

For other options check


asmcmd does not return error text for root user


While running asmcmd commands via root user, error messages are not displayed. But if we run the same command via grid – it returns messages. In the following example, ORACLE_HOME is set to RDBMS home (instead of GI) and we are trying to list the file which does not exist:

[root@rac1 ~]# echo $ORACLE_HOME

[root@rac1 ~]# echo $PATH

[root@rac1 ~]# asmcmd ls +demodg/orcl/tempfile/TEMP.263.10617958
<<<<<<Nothing is displayed here

When a file does not exist, ls command should display ASMCMD-8002: entry 'TEMP.263.10617958' does not exist in directory '+demodg/orcl/tempfile/' error. But in our example, it does not return anything.

In the following example, if we try to copy a file, we see a message about copying a file but actually, the file is not copied because grid user does not have permission under /u01:

[root@rac1 ~]# asmcmd cp +demodg/orcl/tempfile/TEMP.263.1061795851 /u01
copying +demodg/orcl/tempfile/TEMP.263.1061795851 -> /u01/TEMP.263.1061795851

If we run the same command via grid, we get understandable error message:

[grid@rac1 ~]$  asmcmd cp +demodg/orcl/tempfile/TEMP.263.1061795851 /u01
 ASMCMD-9463: operation failed due to lack of write permissions


Environment variables are not set correctly. ORACLE_HOME should be pointing to GI home.


[root@rac1 ~]# export ORACLE_HOME=/u01/app/19.3.0/grid

[root@rac1 ~]# asmcmd ls +demodg/orcl/tempfile/TEMP.263.10617958
ASMCMD-8002: entry 'TEMP.263.10617958' does not exist in directory '+demodg/orcl/tempfile/'