4.16 System Administration

4.16 System Administration

The term "system administration" covers a lot of areas. If you are a good Unix systems administrator, you have many different tasks to deal with and you have the root password. On gort, students don't know the root password, so what can be done is limited. (At least they aren't suppose to know the root password!)

If you have a system available with the root password do the following:

1. Back up the system (dump, rdump, or tar).
2. Add a new user.
3. Create a list of all executable set user id and set group id files owned by root with file lengths and modification times.
4. Restore a file from your backup.

If you are using gort for the system administration lab I would like you to produce a single annotated printout. So as you go through the following steps save your output into a file that you can edit later. One way of doing this is script command. It will produce a file called typescript.

• Backup and Restore
  1. Look in your area with the du command to find a subdirectory with less than 1 Mbyte of data.

  2. Use tar to create a file that contains all of the files in your <1Mbyte area. The command should look something like this:

      
     cd /var/tmp/ 
     tar -cvf your-user-name.tar ~/  
     

     This will create a tar file in /var/tmp/ with your user-name as the file name. tar will try to tar its own output if given the chance.

  3. Do a

     ls -l
     

     to find out the size of the archive file prior to the compression. Write down the size of the file; it will be deleted by the gzip command. Compress the files using the gzip

      
     gzip your-user-name.tar
     

     Compare the size of

     your-user-name.tar 
     

     and

     your-user-name.tar.gz
     

     Write the result of your comparison on your final output.

  4. (Optional) Copy this to a floppy disk using scp. There are PC systems in the Academic Computing Center, Santa Catalina building, room C202 that can be used to do this, or you can do it over the Internet. Make sure that the file is transferred as a binary file.
  5. Create a new subdirectory in your area (called "backup-dir"). Uncompress your file into this area, then expand the tar file to restore your files. The first cd will take you back to your home directory.

      
     cd
     mkdir backup-dir 
     cd backup-dir 
     tar -xvzf /var/tmp/your-user-name.tar.gz
     

     The -x option is for "eXtract". The -v option is for verbose. It will list the file names. The -z option will decompress the tar file on the fly. The -f option is for a following file name. tar defaults to a tape drive.

  6. Save a copy of a recursive directory to be turned in. For this lab turn in all of the requested commands together as a single printout.

     cd
     ls -lR 
     

     This should include your backup-dir and the original subdirectory. Remember to print all of your results together as a single printout for this lab.

• Monitoring the System
  1. Use the df command to look at the file systems on gort. Save a copy of the results.
  2. Use the mount command to look at the file systems mounted on the system. Append this to your output.
  3. Use finger, ps -ae, and ps -al to see what else is on the system. ps is a process status program. It shows what you and other people have running. Append the results of these commands to the file from the previous step.
  4. Run the top command. This shows the top processes on the system. End the command with a q.
  5. Look for suid programs owned by root.

     find /usr/bin -user root -perm -4000 -print
     

     Append this file to your printout.

• System maintenance
  1. Use the following command to copy a set of files keeping the existing permission bits.

     cd
     mkdir from-dir
     mkdir to-dir
     cd from-dir
     ** Put some files in the from-dir directory **
     tar -cf - . | ( cd to-dir; tar xvf - )
     

     Make sure that the to-dir is not in the from-dir. You may want to remove both from-dir and to-dir.

  2. Use the dmesg command to see the "power-up" messages for the system. Include this information in your "turn-in" file.
  3. Clean up your section of the file system by removing unwanted files and directories. You can use rm -r backup-dir to remove all of the files and the new backup-dir sub-directory. Keep your floppy as long as you want it. Also delete /var/tmp/your-user-name.

Turn in the printout and mark it with:

your-name
TABER CIS137
Lab 4.16: System Administration 

and the results of the file compression.

4.16 System Administration