3.1 Searching the course notesIndex

The current term’s course notes are always available on the Internet here: CST8207 GNU/Linux Operating Systems I.

All the current and previous terms notes files are also stored on the CLS. You can learn about how to read and search these files using the command line on the CLS under the heading Copies of the CST8207 course notes near the bottom of the page Course Linux Server.

3.2 The CLS Source DirectoryIndex

All references to the “Source Directory” below are to the CLS directory ~idallen/cst8207/14w/assignment13/ and that name starts with a tilde character ~ followed by a userid with no intervening slash. The leading tilde indicates to the shell that the pathname starts with the HOME directory of the account idallen (seven letters).

You do not have permission to list the names of all the files in the Source Directory, but you can access any files whose names you already know.

3.3 Commands, topics, and features coveredIndex

Review course notes on Partitions and File Systems and Booting and GRUB.

Use the on-line help (man command) for the commands listed below for more information.

• df – show mounted partitions and amount of used/free space (optionally inodes available) on all mounted file systems
• du – recursively display disk usage in directories
• fdisk – to display, create, delete, and manage partitions; option -lis very useful See Partitioning with fdisk
• file – determine what kind of thing a pathname is. Can show disk and partition file system types using option -s and will follow (dereference) symbolic links using option -L (upper case)
• mkfs – create a file system on a device, usually a hard disk partition.
• mkswap – initialize a partition for use as a Linux swap partition.
• mount – mount a file system into the main file system tree or display a list of all mounted file systems, including devices, types, and mount points
• swapon – tell the Linux kernel to use an initialized swap partition.
• umount – detach (unmount) a mounted file system (e.g. that was mounted with mount).
• uname – display system information, including kernel release (version) number
• runlevel – display previous and current system Run Level

3.4 Correct user, command lines, and command outputIndex

• Most of the commands in this assignment require root privilege. You must use the su command to start a shell with the permissions of another user. The root user can use su to become any other user without requiring a password.

• If you start a root subshell, your prompt will tell you if you are the root user by changing to include a # character instead of a $ character. You can also use the commands id or whoami to show your current userid.

• Some answers require you to record command lines. Do not include the shell prompt with your command lines. Give only the part of the command line that you would type yourself.

• Make sure you know the difference between a command line (which is what you type into the shell) and command output (which is what the command displays on your screen). Pay attention to whether the question asks you to record the command line or the command output.

3.5 Backup and Recovery on CentOSIndex

1. Take a snapshot of your virtual machine before you begin each section of this lab so that you can recover back to the snapshot if needed.
   • You can delete the unused snapshots if everything works well.
   • CentOS snapshots are very small and fast compared to your Windows snapshots; you can save lots of them.
2. Are you keeping an external backup copy of all your coursework (including your virtual machines) somewhere? You should be!

3.6 Use a remote login, not the VMware consoleIndex

I recommend that once you have booted your CentOS VM, you connect to it and work using a remote login session (e.g. ssh or PuTTY) where copy-and-paste works and where you can have multiple simultaneous connections into the VM. The VMware console is not friendly.

If you can’t get an SSH (PuTTY or ssh) connection working into your Linux VM, see the Network Diagnostics page.

Note that SSH sessions (and whatever you are doing inside them) do not survive across a VMware suspend. Make sure you save your editor files and exit your SSH session before you pause or suspend your virtual machine. (Editor sessions that run inside the VMware console do survive across suspend and resume, since they don’t depend on a network connection.)

Advanced users may look into the various virtual terminal programs such as tmux and screen that do allow you to suspend and resume your sessions even from a remote login.

3.7 The Answer File answer.txtIndex

Where you are required to record or save a command line or its output into The Answer File, do the command and then copy and record the command line or its output as a separate line into an answer.txt file in your CentOS assignment13 directory. You will be told how many lines to save in the file.

If you can’t answer a question, leave a blank line in this answer file. (The vim option :set number may be useful to you as you edit.)

You can use either nl or cat -n to show the contents of a file with line numbers, to make sure each answer is on its correct line number.

4.1 Set Up – The Base Directory on the CLSIndex

1. Do a Remote Login to the Course Linux Server (CLS) from any existing computer, using the host name appropriate for whether you are on-campus or off-campus.

2. Create the CLS directory ~/CST8207-14W/Assignments/assignment13

3. Create the check symbolic link needed to run the Checking Program, as described in the section Part II - Check and Submit below.

Run Part II - Check and Submit to verify your work so far.

4.2 CentOS: SnapshotIndex

0. Complete your CentOS Virtual Machine Installation and Verification.
   • Make sure it passes the checks for disk sizes and package counts.
   • Complete these critical system administration tasks required in Assignment #08 and Assignment #12:
     1. Create your own personal sysadmin account.
     2. Install and configure the NTP package.
1. Before you begin this assignment, create a snapshot of your CentOS Virtual Machine.
   • Enter a comment explaining where and when you took this snapshot.
   • You can restore back to this snapshot if anything goes wrong.

4.3 CentOS: Set Up – The Base Directory on CentOSIndex

1. In your own account in your CentOS Virtual Machine, also make the directory ~/CST8207-14W/Assignments/assignment13 (the same hierarchy as you have already made on the CLS).

This CentOS assignmment13 directory is the base directory for all pathnames in this assignment. Store your CentOS files and answers below in this base assignment13 directory.

Run the Fetch and Checking Program to verify your work so far.

4.4 CentOS: Add a second disk to your VM: sdbIndex

You will add a second hard disk to your CentOS Virtual Machine, and partition it. The procedure for adding a hard disk to an actual physical computer is different only in the steps that take place while the machine is powered off. Any step carried out while the machine is running would be the same for physical machines as it is for virtual machines. The console of a physical machine is its actual keyboard and monitor, but in the case of a VM, the console is the VMware window of the machine.

Most of the system admin commands in this assignment access the raw disk and will require you to use su to gain root permissions (unless you are in single-user mode and therefore running everything as root). If you get “permission denied” errors, you forgot to use su.

1. If your CentOS Virtual Machine is not already powered off, login and use the correct command to power off the virtual machine.
   • Never user the VMware Power Off button to kill power!
   • Never unplug a running Linux machine!

2. With your CentOS machine still powered off, use the VMware Settings menu for your CentOS VM to add to your VM a virtual 1GB hard disk, accepting defaults for everything except the size. See Create VMware Disk. Create the disk exactly 1GB in size.

3. After adding the new disk, power on your VM, then login as your system administrator user.

4. Ensure the /proc/partitions file contains the second disk you added.
   • Verify that there is a second disk of the correct size:
     • The size of your second drive should be 1048576.
     • Divide: 1048576/1024/1024 to confirm the number of gigabytes.
   • Verify that no partitions are listed for the second disk.
   • If you have any sdb1 or sdb2 or other sdb partitions, this is not a new disk with no partition table. Get help.
   • Note the three-letter device name of the second disk.

5. When the second disk is correct, copy /proc/partitions to file partitions_before.txt in your CentOS base directory (6 lines, 20 words). Remember: all files should be placed under your sysadmin base directory on CentOS.

6. Verify that the three-letter device name for the second disk also exists under the /dev directory. Put a long (ls -l) listing of all names under /dev that start with the first two letters of the new disk name into file sd_all.txt in your base directory.
   • Do not change your current directory.
   • Use the absolute pathnames for the devices.
   • No pipeline or other command is needed.
   • The output should show the absolute paths of two disks, and two partitions in the first disk.
   • Hint

4.5 The useful file command – what is that thing?Index

The Unix/Linux file command is very useful for identifying things in the file system, such as directories, programs, images, files, and special files that might contain file systems, such as disk partitions:

1. Run file -s on (the device name of) each of your two disks. Note that your new empty disk says simply data while your ROOT disk has a very long line full of information about the boot sector and partitions:

   # file -s /dev/sd[ab]
   /dev/sda: x86 boot sector; GRand Unified Bootloader, ...
   /dev/sdb: data

   Save the two lines of file output in a file_s.txt file (2 lines, 44 words) in your CentOS base directory.

4.6 Viewing and Creating Partitions: fdiskIndex

1. First, you must have added a new 1GB hard drive in VMware and rebooted, as described above. Log in to the machine.

Let’s look at the partitions on the first disk (sda):

2. Run (always with root privileges) fdisk -cul /dev/sda and you will see the two partitions on your first (sda) disk that holds your main ROOT file system:

   # fdisk -cul /dev/sda
   Disk /dev/sda: 2147 MB, 2147483648 bytes
   255 heads, 63 sectors/track, 261 cylinders, total 4194304 sectors
   Units = sectors of 1 * 512 = 512 bytes
   Sector size (logical/physical): 512 bytes / 512 bytes
   I/O size (minimum/optimal): 512 bytes / 512 bytes
   Disk identifier: 0x00000000
      Device Boot      Start         End      Blocks   Id  System
   /dev/sda1   *        2048     3074047     1536000   83  Linux
   /dev/sda2         3074048     4194303      560128   82  Linux swap / Solaris

DO NOT OVERWRITE /dev/sda THAT IS YOUR MAIN CENTOS INSTALLATION DRIVE!

Now let’s look at the second disk (sdb) that should have no partitions:

3. Run (always with root privileges) fdisk -cul /dev/sdb and make sure you see Disk /dev/sdb: 1073 MB with no errors and no partitions listed under it.

   # fdisk -cul /dev/sdb
   Disk /dev/sdb: 1073 MB, 1073741824 bytes

   If you don’t see 1073 MB, then shut down, delete the disk, recreate the disk, and reboot until your 1GB disk install works.

Make sure you only change things on this new sdb disk in this section! The sda disk is your Linux ROOT disk; if you damage it you will need to recover back to your snapshot. Make sure you have a snapshot to go back to!

4. In the man page for the fdisk command, locate and make a note of two option letters:
   • The option to “Switch off DOS-compatible mode. (Recommended)”
   • The option to “give sizes in sectors instead of cylinders”

We are now going to run the fdisk program in interactive mode.

To learn more on how to use fdisk, see your in-class notes or see http://tldp.org/HOWTO/Partition/fdisk_partitioning.html

5. Start fdisk interactively as root using the command fdiskdevicename, where devicename is the absolute path of the device corresponding to the new disk under /dev.
   • As fdisk starts, read the upper-case WARNING about DOS-compatible mode. This is a serious (strongly recommended) warning!
   • Type the correct one-letter command to quit the fdisk program. Do not continue.
6. Re-run same fdisk command, this time inserting the two option letters you found in the man page, above. (Keep the same device name.)
   • The DOS WARNING should be gone when you start fdisk with those two options. (One other harmless warning about an invalid flag will remain. This is normal, since the new virtual disk is empty and has not been initialized yet. Ignore the one warning.)
   • Always use these two fdisk options on CentOS. (Other versions of fdisk use these options as defaults.)

You should avoid this DOS warning message in future by always using the -cu command line options to fdisk (RTFM) when you run it, even non-interactively. You might even consider making a shell alias that always supplies these two options to fdisk every time you use it: alias fdisk='fdisk -cu'

7. The fdisk utility should now be running in interactive mode, prompting you for input with a different prompt from your BASH shell prompt: Command (m for help):
   • This prompt is the fdisk utility prompt.
   • Do not type Linux commands into the fdisk program prompt!
   • As it says, type the command letter m for a list of helpful fdisk interactive command letters.

8. Inside interactive fdisk use the command to display the partition table and verify that the disk you are working on is the 1GB disk (1073MB) with no partition table and no partitions.

9. Read the list of Command action commands. Copy the lines below into a file fdisk_info.txt and replace each underscore character with the (one-character) fdisk command letter that does the listed function:

   1. _ save/write partition table to disk (and exit)
   2. _ change a partition's type (system id)
   3. _ exit/quit fdisk without saving changes
   4. _ display/list/print the table of all partitions
   5. _ create/add a new partition
   6. _ show/display/list partition types (system ids)
   7. _ remove/delete a partition

   You will need to use every one of these command letters in this assignment. Make sure you get them right.

10. Use the fdisk command letter that lists all the two-hex-digit partition types. (Partition types are also called “system identifiers”.) Use that list to answer this:

    Add the lines below to the end of the same fdisk_info.txt file and replace the underscore on each line with the hex type number (system id) of the following partition types, making sure you read the numbers correctly from the screen:

    8. _ Linux
    9. _ Linux swap / So
    10. _ HPFS/NTFS
    11. _ W95 FAT32 (LBA)

    The swap line, above, is short for Linux swap / Solaris. You will need all these partition ID numbers later in the assignment.

    Your completed fdisk_info.txt file should be 11 lines 67 words.

Run the Fetch and Checking Program to verify your work so far.

4.7 Creating file systems using mkfsIndex

After partitioning a disk, the next step is making file systems inside the partitions. You must have six partitions available to continue with this section.

To continue with the next sections of this lab, you must have successfully created these six (remaining) partitions on the 1GB disk. Verify that they have exactly the same Device numbers, exactly the same Id and System, approximately the same Start and End, and approximately the same number of Blocks.

       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1            2048      411647      204800   83  Linux
    /dev/sdb2          411648      616447      102400   83  Linux
    /dev/sdb3          616448     1853439      618496    5  Extended
    /dev/sdb4         1853440     2097151      121856    c  W95 FAT32 (LBA)
    /dev/sdb5         1030144     1234943      102400   82  Linux swap / Solaris
    /dev/sdb6         1236992     1851391      307200    7  HPFS/NTFS

Do not proceed until you have the above six partitions created.
The sizes may vary slightly. The System ID must match. The end of the Extended partition must be less than the end sector of the disk. There is a large gap between the start of the extended partition and the start of the first logical partition; this gap corresponds to the space left by the deleted 200M logical partition.

All file system commands in the next part of this lab that refer to a hard disk will use one of the above partitions. Do not continue until you have the above partitions created correctly.

1. Enter the number of sectors in the gap at the start of the extended partition as Line 5 in The Answer File.
   • Read All The Words in the previous paragraphs to know what “the gap” means.
2. Find the device names of the two partitions that have partition type of Linux (System ID 83). (These should be exactly two of the six partitions.)
   1. On the first Linux partition:
      1. Run file -s on this empty partition and note the uninteresting output when the partition has no file system in it.
      2. Use a command to create a Linux type ext3 file system on this partition.
         • Many lines will print on your screen, telling you the characteristics of the file system you just created. Make sure there are no error messages!
         • Record the exact command line you used to create the file system as Line 6 in The Answer File.
      3. Run file -s on this same partition name again to show the type of file system in the partition.
         • You should see one single output line containing this partition type text: ext3 filesystem data
         • Repeat the command and record the one line of partition type output as Line 7 in The Answer File.
   2. On the second Linux partition:
      1. Repeat the above two commands for creating a file system and showing its type, but use a file system type of ext4 this time.
         • Record your command line and the partition type output line on Lines 8 and 9 in The Answer File.
3. On the only W95 FAT partition:
   1. Repeat the above command for creating a file system, but use a file system type of vfat this time.
      • The command will fail with: mkfs.vfat: No such file or directory
      • The commands for creating DOS file systems are not installed!
      • Confirm the missing command by running: whereis mkfs.vfat
      • We can try to fix this by finding and installing the right package.
   2. To locate the missing package run a query command: yum whatprovides '*/mkfs.vfat'
      • yum will update some internal files then tell you that the missing package name is dosfstools (with a version number).
   3. Install the missing dosfstools package.
      • Verify that which mkfs.vfat now finds the command.
      • (If it doesn’t find it, make sure /sbin is in your PATH.)
   4. Again: Repeat the above two commands for creating a file system and showing its type, but use a file system type of vfat this time.
      • If you have installed the missing dosfstools package, everything will work correctly with no errors.
      • Record your command line and the partition type output line on Lines 10 and 11 in The Answer File.
4. On the only HPFS/NTFS partition:
   1. Repeat the above steps for creating a file system, but use a file system type of ntfs this time.
      • The command will fail with: mkfs.ntfs: No such file or directory
      • The commands for creating NTFS file systems are not installed!
      • Confirm the missing command by running: whereis mkfs.ntfs
      • We can try to fix this by finding and installing the right package.
   2. As you did before, try to locate the missing package based on the missing mkfs.ntfs file name.
      • yum will update some internal files then tell you No Matches found
      • This version of CentOS does not support NTFS file systems using the standard yum repositories for software! :-(
      • We could install an experimental NTFS software package, but we don’t want any experimental software on our server machine.
   3. Give up without making any NTFS file system here.
   4. Send an angry note to Microsoft for using undocumented file system formats that have to be experimentally reverse-engineered.

Run the Fetch and Checking Program to verify your work so far.

4.8 Mounting & Unmounting a Linux File system using mountIndex

After partitioning a disk and creating file systems, next comes mounting the new file systems onto existing directories in the system. You must have created six partitions with three new file systems to continue.

1. List all the currently mounted file systems using the mount command with no arguments.
   • You should see six lines, or seven if you use VMware and have a vmware-vmblock device mounted.
   • None of the above new file systems should be visible in the output. If you have any disk partitions mounted other than the ROOT partition (sda1), unmount the partitions now before continuing.
   • Save the mount output as a mount_before.txt file. (6 lines, 36 words or 7 lines, 42 words if you use VMware)
2. Use a single command to create (empty) directories named /mnt/ext3, /mnt/ext4, and /mnt/vfat to use as mount points for all the file systems you successfully created above.
   • If you don’t remember to create the empty directory first, the mount command will generate error messages such as mount point /mnt/ext3 does not exist.
3. Use mount commands to mount all three file systems you created previously, each mounted on its own self-named directory. (Recall that each file system was created with a particular type. Match the partition file system type with the directory name.)
   • You do not need to specify the type of the file system being mounted, because mount can tell. If mount says you must specify the filesystem type then almost surely there is no file system created in that partition. Fix it and then try again.
   • Record as Lines 12-14 in The Answer File the three mount commands you used to mount these three partitions. (Remember: The directories must already exist!)

Reminder: You almost never need the -t option when mounting a file system, since Linux knows the type by looking inside the partition. If mount ever gives the error you must specify the filesystem type, it is because there is no file system created inside that partition. The file -s command can confirm this for you. Create the file system first, then mount it.

4.9 Preparing a Swap Partition using mkswap and swaponIndex

1. Use one command to initialize the Linux swap partition on your new 1GB disk.
   1. Record the command line you used as Line 15 in The Answer File.
   2. Record as Line 16 in The Answer File the output of using file -s on the Linux swap partition.
      • The output should include the words swap file
2. Use one command to tell the kernel to use the new swap device.
   • Record the command line you used as Line 17 in The Answer File.
3. Display the list of active swap partitions.
   • Save the output of this command in a swap.txt file. (3 lines, 15 words)
4. Disconnect the swap area you just connected.
   • Only one swap partition should remain, on your first disk.

Run the Fetch and Checking Program to verify your work so far.

4.10 Kernel Version Number (release number)Index

Your Linux kernel has a version number, as in “What version of the kernel are you running? I’m running version 2.6.32”.

Unfortunately, the command that prints system information, including the kernel version number, calls the number a kernel release number, because it uses the option name version to stand for the kernel compile date. When using this system information command you must use the option named release to display the kernel version number.

1. Display only the version (release) of the Linux kernel that is running on CentOS (19 characters):
   • Record the command line you must use as Line 18 in The Answer File.
   • Record the one line of output for CentOS as Line 19 in The Answer File. (The output starts with the digit 2 on CentOS.)
   • Log in to the CLS find out what kernel version it is running. Record the one line of output for the CLS as Line 20 in The Answer File. (The output starts with the digit 3 on the CLS – the CLS runs a newer kernel than CentOS.)

Run the Fetch and Checking Program to verify your work so far.

4.11 Booting into single-user mode (changing forgotten root password)Index

If you find yourself locked out of a Linux machine, and you have access to the console, booting into single user mode will will often not require a password, and in single-user mode you are given a root shell and can change passwords or perform various other repair tasks. (Some systems do password-protect single-user mode, in which case you would need to boot a “live” or “rescue” CD to reset your root password.)

Review Booting and GRUB.

This section depends on a successful CentOS Virtual Machine installation, including a visible (not hidden) GRUB menu. (You made these changes when you configured CentOS in an earlier assignment.)

To change a forgotten root password or do maintenance on the system that requires it to be quiescent (no users or disk activity), you can boot your system in a restricted single-user mode that does not start many system daemons and goes directly into a root shell prompt on the system console without requiring a password.

The system should not be left in single-user mode; many service programs are not started. Networking may not be enabled; you may not even be able to log-in remotely in single-user mode.

1. View your CentOS GRUB configuration file and look at the (very long) kernel line in that file. Note all the options used on the right end of the kernel line; you will see them again soon.
   • Record on Line 21 in The Answer File the Linux absolute pathname of this GRUB configuration file.

2. Record on Line 22 in The Answer File the kernel option keyword used in booting a machine single-user (maintenance mode). (one word)

3. Safely reboot your CentOS VM into the GRUB menu and halt the time-out:
   • When the boot process begins, if you correctly disabled the hiddenmenu command in GRUB, you will boot directly to the GNU GRUB menu where you should see a one-line list of CentOS systems to boot and at the bottom a 30 second countdown in progress.
   • Interrupt the countdown by pressing an arrow key. (If you didn’t disable hiddenmenu, when the countdown is interrupted your system should display the one-entry GRUB menu.)

CentOS 6 GRUB Menu

4. Now, just as the GRUB menu instructions tell you, to modify the kernel arguments you press just the single letter a – just the letter key, no [Enter] key!
   • After pressing a you will see your cursor on a line that ends with the same kernel arguments you viewed earlier in the configuration file.
   • You can use the [Home] key to zoom to the left end of the kernel options line, and the [End] key to zoom to the right.

CentOS 6 Kernel Options

5. Modify this kernel options line so that the system will boot single-user. (Add the correct kernel option keyword to the right end of the line.)
   • As the instructions say, push [Enter] to accept your changes and directly boot the system using these new kernel options.
   • These changes to the kernel options are not saved back into the configuration file – they are only in effect for this boot menu.
   • (If you wanted to abandon your changes and leave the menu entry unmodified, you would have used the Escape key, as it says.)
6. The system should come up in single-user (maintenance) mode with a root shell prompt. (If you get a login prompt, you didn’t use the right kernel option keyword. Reboot into GRUB and try again.)
   • You can perform any root function at this prompt, including changing passwords (even the root password).
   • Often single-user mode has no networking enabled and only a minimal number of file systems mounted.

7. From the single-user shell, place a full list of all processes for all users, BSD format, text user name (not numeric UID), full wide listing (not truncated at all), into a psbsd_single.txt file. (All assignment answer files must be saved in your sysadmin base directory.) The output should be approximately 52 lines and 4KB. All the processes will be owned by root. The first two lines should look similar to this:

   USER  PID %CPU %MEM  VSZ   RSS TTY  STAT START   TIME COMMAND
   root    1  0.0  0.5 2900  1380 ?    Ss   16:35   0:01 /sbin/init

   Remember to fix the owner and group of the file.

8. Use the command that displays the previous and current Run Level (two words on one line) and record this line of output as Line 23 in The Answer File.

9. Leave single-user mode and let the system finish booting into full multi-user mode:
   • Leaving single-user mode does not mean rebooting the machine; do not reboot or shut down the machine.
   • Go directly from single-user to multi-user mode without a shutdown or reboot.
   • The login prompt should appear on the console.
10. Log in as your sysadmin account (optionally use an SSH login, not the terrible console window) and repeat the command that displays the previous and current Run Level and save the output as Line 24 in The Answer File (two more words on one line).
    • If you rebooted the machine, you won’t have the right answer here. Boot back into single-user mode and then transition to multi-user mode without a shutdown or reboot.

Run the Fetch and Checking Program to verify your work so far.

4.12 When you are All DoneIndex

That is all the tasks you need to do.

Check your work a final time using the Fetch and Checking Program and save the output on the CLS as described below. Submit your mark following the directions below.

Optional: Keeping your main CentOS Virtual Machine snapshot, remove any intermediate snapshots you no longer require, to free up disk space. - Be careful not to remove your current work!

5.1 Part I - Fetch and CheckIndex

Do all the following steps on your CentOS Virtual Machine. Read through the whole list before you start typing anything. An example of what to type is given below the descriptions that follow.

Failure to read all the words will lock your account out of the CLS.

1. Log in to CentOS. Use your sysadmin non-root account (same userid as Blackboard).
2. Create a directory in your sysadmin account named CST8207-14W/Assignments/assignment13 (use the same directory hierarchy as you already have in your own account on the CLS). This is your base directory for this assignment.
3. Change to the above sysadmin base directory (on CentOS!).
4. As shown below, use curl to get a copy of the Fetch program from the given URL into a file named do.sh. Make sure you have a file named do.sh in your sysadmin base directory. You only need to download this once per assignment.
5. Warning: If you printed this page on paper, you may not be able to scroll right to read the whole web URL that you must pass to the curl program.

$ whoami ; hostname ; pwd
abcd0001                                 # your userid, not abcd0001
abcd0001                                 # your userid, not abcd0001
/home/abcd0001/CST8207-14W/Assignments/assignment13
$ url=http://teaching.idallen.com/cst8207/14w/notes/data/assignment13do.sh
$ curl -A mozilla "$url" >do.sh
[... make sure you scroll right to read the full web URL above ...]
[... various download statistics print here ...]

$ fgrep -i 'error' do.sh    # make sure no errors (no output)
$ head -n1 do.sh            # make sure it's a shell script
#!/bin/sh -u

5. You must run the do.sh script you just downloaded. You must run the script as the root user with the USER environment variable set to your own CLS account userid. (Do not use abcd0001; use your own.) Failure to set the USER= variable as shown below will cause your account to be locked out of the CLS.

   Use su to run the do.sh script:

   $ echo "$USER" ; pwd
   abcd0001                                              # your userid, not abcd0001
   /home/abcd0001/CST8207-14W/Assignments/assignment13   # your userid, not abcd0001
   $ su -c "USER=$USER sh do.sh"   # must be double quotes, not single

   This do.sh script runs a Fetch program that will connect from your CentOS machine to the CLS using your account name in the USER variable. It will copy selected files from your CentOS machine to your assignment13 directory on the CLS. It will then run the checking program on the CLS to check your work. You will need to answer one question about your IP address, and then wait and type in your CLS password, as shown below:

   ---------------------------------------------------------------------------
   abcd0001: FETCH version 3.  Connecting to CLS as USER='abcd0001' using ssh
   ---------------------------------------------------------------------------
   abcd0001: Use local Algonquin IP cst8207-alg.idallen.ca [y/N/?]? n
   abcd0001: Please wait; using ssh to connect to user 'abcd0001' on cst8207.idallen.ca ...
   *** COURSE LINUX SERVER ***
   abcd0001@cst8207.idallen.ca's password:         # enter your CLS password
   ---------------------------------------------------------------------------
   idallen-ubuntu assignment13fetch_server.sh version 9 run by abcd0001.
   Please wait; collecting info from abcd0001 Virtual Machine
   ---------------------------------------------------------------------------
   VM files collected into CST8207-14W/Assignments/assignment13/abcd0001.tar.bz on CLS.
   Now running checking program for abcd0001 on CLS:
   [... checking program output appears here ...]

5.2 Part II - Check and SubmitIndex

When you are done with your assignment, you need to run the checking program one last time on the CLS (not from CentOS) and submit the output file, as follows:

Do all this on the Course Linux Server when you are ready to submit:

1. There is a Checking Program named assignment13check in the Source Directory on the CLS. Create a Symbolic Link to this program named check under your new assignment13 directory on the CLS so that you can easily run the program to check your work and assign your work a mark on the CLS. Note: You can create a symbolic link to this executable program but you do not have permission to read or copy the program file.

2. Execute the above “check” program on the CLS using its symbolic link. (Review the Search Path notes if you forget how to run a program by pathname from the command line.) This program will check your fetched CentOS work, assign you a mark, and display the output on your screen. (You may want to paginate the long output so you can read all of it.)

   Remember: The checking program does not fetch new files to the CLS from your CentOS VM. You must run the Fetch program on your CentOS VM to update the fetched files on the CLS so that the checking program can mark them on the CLS.

   You may run the “check” program as many times as you wish, to correct mistakes and get the best mark. Some task sections require you to finish the whole section before running the checking program at the end; you may not always be able to run the checking program successfully after every single task step.

3. When you are done with checking this assignment, and you like what you see on your screen, redirect the output of the Checking Program into the text file assignment13.txt under your assignment13 directory on the CLS. Use the exact name assignment13.txt in your assignment13 directory. Case (upper/lower case letters) matters. Be absolutely accurate, as if your marks depended on it. Do not edit the file.
   • Make sure the file actually contains the output of the checking program!
   • The last text line of the file should begin with: YOUR MARK for
   • Really! MAKE SURE THE FILE HAS YOUR MARKS IN IT!
4. Transfer the above assignment13.txt file from the CLS to your local computer and verify that the file still contains all the output from the checking program. Do not edit this file! No empty files, please! Edited or damaged files will not be marked. You may want to refer to your File Transfer notes.
   • Make sure the file actually contains the output of the checking program!
   • The last text line of the file should begin with: YOUR MARK for
   • Really! MAKE SURE THE FILE HAS YOUR MARKS IN IT!

5. Upload the assignment13.txt file under the correct Assignment area on Blackboard (with the exact correct name) before the due date. Upload the file via the assignment13 “Upload Assignment” facility in Blackboard: click on the underlined assignment13 link in Blackboard. Use “Attach File” and “Submit” to upload your plain text file.

   No word-processor documents. Do not send email. Use only “Attach File”. Do not enter any text into the Submission or Comments boxes on Blackboard; I do not read them. Use only the “Attach File” section followed by the Submit button. If you need to comment on any assignment submission, send me email.

   You can upload the file more than once; I only look at the most recent. You must upload the file with the correct name; you cannot correct the name as you upload it to Blackboard.

6. Verify that Blackboard has received your submission: After using the Submit button, you will see a page titled Review Submission History that will show all your submissions.
   1. Verify that your latest submission has the correct 16-character, lower-case file name beside the Attached Files heading.
   2. The Submission Field and Student Comments headings must be empty. (I do not read them.)
   3. Save a screen capture showing the uploaded file name. If there is an upload missing, you will need this to prove that you uploaded the file. (Blackboard has never lost a file.)

   You will also see the Review Submission History page any time you already have an assignment attempt uploaded and you click on the underlined assignment13 link.

   You cannot delete an assignment attempt, but you can always upload a new version. I only mark the latest version.

7. Your instructor may also mark files in your directory in your CLS account after the due date. Leave everything there on the CLS. Do not delete any assignment work from the CLS until after the term is over!

• I do not accept any assignment submissions by email. Use only the Blackboard Attach File. No word processor documents. Plain Text only.

• Use the exact file name given above. Upload only one single file of Linux-format plain text, not HTML, not RTF, not MSWord. No fonts, no word-processing. Linux plain text only.

• NO EMAIL, WORD PROCESSOR, PDF, RTF, or HTML DOCUMENTS ACCEPTED.

• No marks are awarded for submitting under the wrong assignment number or for using the wrong file name. Use the exact 16-character, lower-case name given above.

• WARNING: Some inattentive students don’t read all these words. Don’t make that mistake! Be exact.

READ ALL THE WORDS. OH PLEASE, PLEASE, PLEASE READ ALL THE WORDS!