My cluster has dedicated nodes that take a role of a client. Users can connect to these clients with their own private keys and they have their own home directory.
Until now, the home directory was the default /home/username. Lately, Ambari has been warning me that client nodes are running out of disk.
I have added one volume to the client node and configured a new home for the users. How I am attaching volume to an instance is described here.
The new volume is mounted to folder /user. I am trying to imitate Hadoop’s filesystem. Since some users already exist and have their home directories under /home, I have to take care of them first.
Create /user folder
Create the folder where users’ home will reside
sudo mkdir /user
Move existing user
Moving existing user to a new home directory:
sudo usermod -m -d /user/test1 test1
If the new directory does not exist yet, usermod is going to create it.
After the command is finished, the directory /home/test1 is not available anymore and folder /user/test1 has become the new home directory for user1.
-m move contents of the home directory to the new location (use only with -d)
-d new home directory for the user account
*-taken from usermod man.
Now we can check some details of the user with the following command:
The following output is given:
Login: test1 Name:
Directory: /user/test1 Shell: /bin/bash
Never logged in.
If you run the usermod command on a user that is logged in, usermod is going to report an error:
usermod: user user2 is currently used by process 13995
Running ps aux on this process
ps aux | grep 13995
Reveals that the user user2 is logged in:
user2 13995 0.0 0.0 103568 2468 ? S 11:59 0:00 sshd: user2@pts/2
Changing configuration for new users
Opening adduser.conf file
sudo vi /etc/adduser.conf
and changing (first uncommenting if needed!) the value for parameter DHOME does the trick:
Upon creation of a new user
sudo adduser newuser
this new user now has a new home directory on the attached volume. When logging in as newuser and running command pwd, the output is
The existing users’ directories have now been moved to /user which is a dedicated volume for user files. The configuration file /etc/adduser.conf has been altered so that the new users are automatically defined as having home directory under /user.