Chapter 10: Standard Operating and Maintenance Procedures

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Chapter 10 Standard Operating and Maintenance
Procedures
Lecture 12 The 1st of 2 on Chapter 10

• A Guide to Operating Systems Troubleshooting
  and Problem Solving

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Chapter Objectives

• Explain file system maintenance techniques for
  different operating systems
• Perform regular file system maintenance by
  finding and deleting unused files and directories
• Perform disk maintenance that includes
  defragmenting, relocating files and folders,
  running disk and file repair utilities, and
  selecting RAID options
• Set up and perform disk, directory, and file
  backups
• Explain how to install software for best
  performance
• Tune operating systems for optimal performance

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File System Maintenance

• Some basic rules for creating a file structure
  include
• Keep the number of directories in the root
  directory to a minimum
• Keep operating system files in the default
  directories recommended by the vendor
• Keep different versions of software in their own
  directories
• Keep data files in directories based on the
  function of those data files
• Design home directories to match the functions of
  users in an organization

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Applications Directories and Subdirectories
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UNIX Directories

• \bin houses system files
• \dev contains device files
• \etc holds configuration files
• \home holds user home directories
• \mnt is used for mounting removable drives such
  as CD-ROM drives
• \sbin contains system files
• \mp holds temporary files
• \usr contains programs
• \var holds files that change frequently

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Typical UNIX Root Directory Structure
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Windows 98 Operating System Files in the Windows
Folder
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Operating System Directories
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Windows-Based Application Software Components
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Finding and Deleting Files

• A well-organized file structure on the computer
  makes it easier to find and delete unneeded files
• Hard disk drives should be kept to under 80 full
• Drives that are over 80 full are subject to
  excessive wear and are more likely to have
  problems or fail

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Finding and Deleting Files in Mac OS

• Make sure that you do not run out of disk space
• The Mac OS provides an easy way to assess
  available disk space by simply checking the
  header information in the HD window to display
  the contents of any folder
• The header provides information about the number
  of items and the available disk space in MB
• Use the Sherlock utility for complex search
  criteria
• Files are not truly deleted until they are purged
  by emptying the trash

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Finding and Deleting Files in NetWare

• There are several ways to manage files
• NetWare Administrator
• NetWare clients
• Network Neighborhood
• NDIR runs from a NetWare DOS and provides
  important information about directory space
• When you create a home directory for a user, make
  sure you restrict the size of the directory by
  using NetWare Administrator

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NetWare File System Commands

• /AC BEF to view files that have not been accessed
  since the date specified
• /DATE to view information based on the date
• /DO to view all information on directories
• /OW to view files by owner
• /REV SORT SI to sort files listing the largest
  first
• /SPA to view how directory space is used
• /SORT OW to sort files on the basis of ownership
• /VOL to view information by volume

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UNIX File System Commands

• Use the ls command to view UNIX files.
• Options associated with this command
• a lists all files
• d presents file information on the basis of the
  specified argument
• F identifies the directory contents on the basis
  of directory, executable files, and symbolic
  links (since UNIX is case sensitive, this option
  should be capitalized while the others are not)\
• I displays the inode number for each file

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UNIX File System Commands (Continued)

• l presents a detailed information listing
  including permissions and file size
• n displays UIDs and GIDs of those who have access
  to files
• r sorts files in reverse alphabetic order
• s displays files on the basis of the data when
  they were last modified
• u displays files on the basis of the time when
  they were last modified
• Files and folders are deleted in UNIX by using
  the remove (rm) command
• Two options can be added to the command -i and
  -r

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Finding Files in UNIX

• Files can be found on the basis of the filename.
  
• A wildcard character () can be associated with
  part of the name, the size of the file, and the
  last time it was accessed or modified
• Commands used with find
• atime for last accessed time
• ctime for last changed time
• mtime for last modification time
• name for the file name, including the use of
  wildcard searches
• print to print the results of the find
• size for file size (in blocks or in bytes
  (specified by c after value)

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More UNIX File System Finding Commands

• UNIX provides commands to help you assess the
  allocation of disk space
• df enables you to view information on the basis
  of the file system It provides statistics on the
  total number of blocks, number used, available
  and the percent of capacity used
• du displays statistics for a given directory or
  subdirectory
• On a UNIX computer that acts as a server, the
  administrator has the option to set up disk
  quotas called edquota command

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UNIX Disk Quotas for Server Users
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Finding and Deleting Files in Windows 95/ 98 and
in the Window NT Family

• Temporary files often begin with a tilde () as a
  first character or have a .tmp extension
• In Windows NT the operating system is located in
  the \Winnt folder
• temporary files are found in this folder and in
  the \Winnt\System32 and \Winnt\Temp folders
• Before searching for temporary files, make sure
  to close all active applications so that there
  are no open temporary files

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Finding and Deleting Files in Windows 95/98 and
Windows NT Family (Continued)

• Windows 95/ 98 and Windows NT retain deleted
  files in the Recycle Bin by default
• There is an option to turn off retention of
  deleted files or to periodically empty the
  Recycle Bin
• By default, the Recycle Bin can grow to occupy
  10 of the available hard disk storage

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Windows NT 4.0 Find Dialog Box
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Temporary Files Found in Windows NT 4.0
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Maintaining Large and Small System Disks

• Maintain the integrity of files and ensure disk
  performance using the following techniques
• Defragment disks
• Move files to spread the load between multiple
  disks
• Use disk utilities to repair damaged files
• Deploy RAID techniques that extend the life of
  disks and provide disk redundancy

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Defragmenting Disks

• Fragmentation - unused space develops between
  files
• As the operating system deletes files, creates
  new files, and modifies files, the unused space
  between them grows and becomes scattered
  throughout the disk
• The disk read-write head begins to move over more
  disk area to find individual files
• disk performance suffers
• the read-write head works harder

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More About Defragmenting

• In mainframes and minicomputers that have large
  hard disks, fragmentation is sometimes obvious
  because the constant activity of the read-write
  head causes the disk drive cabinet to literally
  move across the floor
• In small disk drives, the problem is apparent
  through excessive noise and hard disk activity.
  (Disk Thrashing)
• Defragmentation is the process of removing the
  empty pockets between files and other information
  on the hard disk drive

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Files Located Contiguously on a Disk
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A Fragmented Disk
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Defragmenting Disks (Continued)

• There are two ways to defragment
• Take a complete backup of a disks contents and
  then perform a full restore
• Run a disk defragmentation tool
• Surface analysis tools are destructive to data
• DOS, Windows 3.1/ 3.11, Windows 95/ 98 have
  built-in defragmentation utilities

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Disk Defragmenter in Windows
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Defragmenting in Windows NT Family

• Windows NT 4.0 does not come with a defragmenting
  tool, but third-party software companies offer
  them
• Windows NT server has frequent write and update
  (Highly volatile and Highly active) activity. It
  may need to be defragmented every month

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Defragmenting in UNIX

• Some versions of UNIX come with defragmenting
  tools, such as defragfs
• They may not rearrange files
• Compunix, DEC, Eagle Software, and other
  companies offer full-feature UNIX disk
  defragmentation tools

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Defragmenting in Mac OS

• The Mac OS is designed to minimize disk
  fragmentation, but third-party tools are
  available for systems that experience high use
• SYMANTECs Norton Utilities for Macintosh
  includes a Mac OS version of SpeedDisk for
  defragmenting
• memory fragmentation is more likely to need
  attention in the Mac OS

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Posting Questions

• Research defragmentatiton tools. Why do you
  suppose that defragmentation tools have been a
  mixed blessing in the Unix environment? Do they
  work, Why? Dont they work, why?

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End