Updated: 2012-10-21 23:32 EDT

1 Course Linux Server repairsIndexup to index

See the CST8207 Blackboard Announcements (also sent to your Algonquin EMail) for news regarding the Course Linux Server repairs.

2 Readings, Assignments, Labs, and ToDoIndexup to index

3 Lecture Notes for This WeekIndexup to index

3.2 From the Classroom Whiteboard/ChalkboardIndexup to index

3.2.1 Your in-class notes go here - take notes in class!Indexup to index

The command that creates new names for existing files is ln (link):

$ ln source target

Know the meaning of each of the output fields of ls -dils:

      2   4 drwxr-xr-x  24 root root   4096 Sep 12 12:12 /
2883589   4 drwxr-xr-x   2 root root   4096 Oct  5 02:05 /bin
2883666 104 -rwxr-xr-x   1 root root 105776 Feb 23  2011 /bin/ls
2883587  12 drwxr-xr-x 186 root root  12288 Oct 17 13:38 /etc
2889578   4 -rw-r--r--   1 root root   2209 Mar 19  2012 /etc/passwd
  1. inode number
  2. size in disk blocks
  3. (one char) type (file, directory, symlink, etc.)
  4. (9 chars) permissions (3 for user, 3 for group, 3 for other)
  5. link count (count of names for this inode)
  6. userid of owner
  7. userid of group
  8. size in bytes (characters)
  9. date last modified
  10. name

If two names reference the same inode, all the above attributes (except the name) will and must be identical for the two names. All the above attributes, except the name, are stored with the inode itself. The names are stored in directories.

3.2.2 I’ve been telling you some simplification liesIndexup to index

  • Lie: Names are stored with the things they name.
    • Truth: Names and inode numbers are stored in directories.
  • Lie: the rm command removes files.
    • Truth: The rm command only removes names. When all the names are gone, only then are the file data blocks released.
  • Lie: All file system objects have a unique inode.
    • Truth: All things on the same file system (disk partition) have a unique inode. Different file systems have separate disk space and inode trees, so the same inode number will mean different file system objects in different file systems. You can’t hard link objects between different file systems. (Use symbolic links instead.)

4 Real Sysadmin WorkIndexup to index

5 Ubuntu Linux on your PhoneIndexup to index

SSH Terminal on Phone

SSH Terminal on Phone

Ubuntu Desktop on Phone

Ubuntu Desktop on Phone

See also Ubuntu on Phone for more screen shots.

| Ian! D. Allen  -  idallen@idallen.ca  -  Ottawa, Ontario, Canada
| Home Page: http://idallen.com/   Contact Improv: http://contactimprov.ca/
| College professor (Free/Libre GNU+Linux) at: http://teaching.idallen.com/
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