Access Linux File Systems

# Access Linux File Systems
      ## Dennis Kibbe
      ### Mesa Community College
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      ---
      
      # Module Outline
      1. Introduction
      1. Identify File Systems and Devices
      1. Quiz
      1. Mount and Unmount File Systems
      1. Guided Exercise
      1. Key Takeaways
      1. Resources
      1. Graded Lab
      Note: 
      ---
      
      # Learning Objectives
      *After completing the work in this module you will be able to:*
      1. Find the device mounted on a directory.
      1. Add and remove file systems from the file system hierarchy.
      1. Search for files using the `locate` and `find` commands.
      Note:
      ---
      
      # Identify File Systems and Devices
      ![Diagram of Linux Hierarchy Filesystem](../images/fsh.png)
      Note: Before a file system can be used it must be mounted on an existing directory.
      ---
      
      # Disk Partitions
      ![screenshot of a partitioned disk](../images/guid_partition_table.png)
      Note: 
      --- 
      
      # Logical Volume Management (LVM)
      ![diagram of lvm partitioning](../images/lvols.png)
      Note: 
      ---
      
      # Examine File Systems
      ```
      dennisk@sahuaro:~$ df -h
      Filesystem              Size  Used Avail Use% Mounted on
      tmpfs                   1.6G  2.4M  1.6G   1% /run
      /dev/nvme0n1p2          468G   53G  392G  12% /
      /dev/nvme0n1p1          511M  6.1M  505M   2% /boot/efi
      /home/dennisk/.Private  468G   53G  392G  12% /home/dennisk
      ```
      Note: 
      ---
      
      # Quiz
      ## Identify File Systems and Devices
      Note: 
      ---
      
      # Mount and Unmount File Systems
      ```
      dennisk@sahuaro:~$ lsblk
      NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
      nvme0n1     259:0    0 476.9G  0 disk
      ├─nvme0n1p1 259:1    0   512M  0 part /boot/efi
      └─nvme0n1p2 259:2    0 476.4G  0 part /
      ```
      Note: 
      ---
      
      # Mount File System with the Partition Name
      ```
      [root@servera ~]# mount /dev/vda4 /mnt/data
      ```
      Note: 
      ---
      
      # Mount File System with Partition UUID
      ```
      dennisk@sahuaro:~$ lsblk -fp
      NAME             FSTYPE FSVER LABEL UUID                                 FSAVAIL    FSUSE% MOUNTPOINTS
      /dev/nvme0n1
      ├─/dev/nvme0n1p1 vfat   FAT32       F8AD-FB69                             504.9M     1% /boot/efi
      └─/dev/nvme0n1p2 ext4   1.0         e84f5519-cf89-4e75-9b9b-4e7dd027f7fa  391.7G    11% /
      ```
      Note: 
      ---
      
      # Unmount File Systems
      ```
      [root@servera ~]# umount /mnt/data
      ```
      Note: If a filesystem is in use (has open files) all processes must be stopped before the file system can be unmounted.
      ---
      
      # The `/etc/fstab` File
      ![The /etc/fstab file](../images/fstab.png)
      Note: The `/etc/fstab` file contains file systems which are mounted at boot. Here the root file system and the efi filesystem are mounted.
      ---
      
      # Guided Exercise
      ## Mount and Unmount File Systems
      Note: 
      ---
      
      # Locate Files on the System
      Note: 
      ---
      
      # The `locate` Command
      ```
      dennisk@sahuaro:~/Public/cis126rh$ locate ssh
      /etc/ssh
      /etc/X11/Xsession.d/90x11-common_ssh-agent
      /etc/gufw/app_profiles/ssh.gufw_service
      /etc/ssh/ssh_config
      /etc/ssh/ssh_config.d
      ...output omitted...
      Note: 
      ---
      
      # The `find` Command
      ```
      dennisk@sahuaro:~$ find -name *ssh*
      ./Public/images/ssh_remote_exit.png
      ./Public/images/ssh_permissions_too_open.png
      ./Public/images/openssh.jpg
      ./Public/images/ssh_remote.png
      ./.ssh
      ```
      Note: 
      ---
      
      # Guided Exercise
      ## Locate Files on the System
      Note: 
      ---
      
      # Key Takeaways
      1. Storage devices are identified by block device file type.
      1. File systems are mounted on an existing directory.
      1. A file sytem caan not be unmounted if there are open files on the file system.
      1. Removable media is mounted under `/run/media`.
      1. You can use the `lsblk` command to list block devices.
      1. The `find` command searches in real time while the `locate` command uses an index file.
      Note:
      ---
      
      # Resources
      - [An introduction to the Linux /etc/fstab file](https://www.redhat.com/sysadmin/etc-fstab)
      - [2 Minute Linux Tip: The find Command](https://www.infoworld.com/video/89095/linux-tip-how-to-use-the-find-command)
      - [What Is a Block Device?](https://phoenixnap.com/glossary/block-device)
      Note: Here are some resources for the topics covered in this chapter.
      ---
      
      # Graded Lab
      ## Access Linux File Systems 
      ![Screenshot of a sample grading script](../images/lab_techs.png)
      Note: 
      ---
      
      
      ![Mesa Community College logo](../images/mcc_logo.png "Mesa Community College")
      Note: This ends this slide presentation. I hope you found it useful.