Unix - Advanced Concepts

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Unix - Advanced Concepts

• System Administration

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More File Systems
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Mount

• Is used to mount (connect) a partition on a local
  hard drive to your unix file system (local).
• Can be used to connect a servers partition to
  your local client for access
• (client/server networking).
• A mapping process

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Mount Commands

• mount
• see what is currently mounted
• mount -t type /dev/hda1 /mnt
• where "type" is either nfs (over network,
  client/server) or ext3 (for local hard drive
  partition linux native) "/dev/hda1" is the
  physical partition on the given hard drive /mnt
  is the empty directory (mount point) where the
  partition
• is mount to
• Note- ext3/ext2 is a type of UFS (unix file
  system) used by linux

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For Example

• mount -t ext2 /dev/hda4 /home
• mount the home directory on /dev/hda4 to the
  location /home (local mounting)

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Over a Network

• Server
• Share directory to be accessed by clients
  (share command)
• Client
• mkdir /usr/local
• create empty directory, a mount point
• mount -t nfs server1/usr/local /usr/local
• mount, over the network (nfs) from the server
  called "server1",mount its /usr/local partition
  onto the client at the same location.
• umount /home
• un mount a partition
• Note - all file systems normally mount up, at
  boot time, via the /etc/fstab (/etc/vfstab) file

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Adding a New Disk Drive

• Partition and format the new drive
  
• sun - format
• linux - disk druid or fdisk
• Create file system on new partition
• sun - newfs
• linux - mkfs
• Mount partitions via mount command or at bootup
  via
• sun - /etc/vfstab
• linux - /etc/fstab

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fsck - file system check

• Tool to check and fix a file
• system
• Automatically attempts to fix
• things, if file system is corrupted.
• You can fun this manually...and it also runs
  automatically at boot time if the system was not
  cleanly shutdown.

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Install Software
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Compressed Files

• 2-1 ratio
• file --gt file.gz
• Use zip/gzip to compress, and unzip/gunzip to
  uncompress

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Tar

• Archive format
• Gathers many directories/files
• into one single tape or onto one single file
  (called a tar file or tarball).
• Also saves group/ownership/permission info and
  date info for each file/directory.

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Examples of Tar

• tar -tvf file.tar
• This takes a tar file (file.tar) and shows the
  table of contents of the file (-t option) in a
  verbose (-v option) way.
• tar -xvf file.tar
• This will extract all file/directories from the
  above tar file, into the current directory. (-x
  extract -v verbose).
• Permissions ownership/group will be set
  correctly.
• (untar)
• tar -cvf file.tar directory-name
• The entire contents of the given directory, and
  everything in it, will be copied into the tar
  file (file.tar) including permissions/ownership/gr
  oup. (-c create -v verbose)

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• Thus when you install software, it often comes in
  a compressed tarball. Something like
  "file.tar.gz". Thus you need to first uncompress
  the file and then untar it.
• gunzip file.tar.gz
• Creates the file file.tar)
• tar -xvf file.tar
• This extracts all the software)
• Note- make sure to do the above in the correct
  location on the system.

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Other Methods to Install Software

• sun - pkgadd/pkgrm
• install/remove scripts
• linux - rpm
• red hat package manager
• Note- when done installing software, always check
  ownership/group/permissions and also test to make
  sure it works correctly (not just as root).

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Source Code

• When the software you get is just source code,
  and not binaries, you will have to compile it
  first to get the binaries created and installed.
  Typical set of steps
• read README file and other docs
• Often have a Makefile that may need adjustment
  (edit)
• May have a command called "./configure" to create
  a Makefile for you.
• ./make
• run the Makefile, this will compile, link and
  create the binaries from the source code
• ./make install
• copies all binaries to final location on the
  system

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Install O.S. Patches
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Linux

• "patch" program, to add patches
• to linux source code
• Then build a new kernel
• (compile linux source code)
• Install new kernel into /boot/vmlinuz-2.0.xxx

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Solaris

• patchadd 106751.tar.gz
• patchrm
• Easy scripts to add/remove patches.
• Patches for solaris come in a compressed/zipped
  and tar format.
• No need to build (compile source code ) a new
  kernel.

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THE END!!