Back up your files

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Back up your files

• Realistic guidelines for an effective, staged
  approach

2
End User backups

• Nobody has the server space or network bandwidth
  to back up everybodys hard drives.
• Having good backups would solve a lot of problems
  quickly.
• The trick is balancing between security and
  convenience, minimizing cost.

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The core issue

• A file copied to two different media in different
  places probably wont be destroyed in both places
• The second, less convenient copy should be in a
  safe, remote place

4
Make a sustainable plan

• Prioritize your files the forgotten step
• Choose methods appropriate to these priorities
• Make an explicit plan for using those methods,
  including a schedule

5
Things to back up differently

• Your most important documents
• Less crucial current documents
• Older documents
• OS and applications

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Your first, best step

• Choose your most important files
• Keep them on Home Directory
• http//www.itc.virginia.edu/homedir
• Automatically backed up every 2 hours for 24
  hours, each midnight for a week, each week for a
  month, older on tape
• Restore your files via a Web page
• https//www.people.virginia.edu/cgi-local/ww/menu

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Home Directory

• Free for faculty, staff students
• Limited space
• 125MB for faculty staff
• 100MB for grad students
• 75MB for undergrads
• Dependent upon network connection
• Windows Offline files supplements this

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Windows offline files

• Available in Windows 2000, XP
• Keeps a local copy of networked files for working
  while network is down
• Somewhat arcane to set up
• Works with Home Directory
• Use for files you cant do without if the network
  fails

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Other automatic backup options

• Premium Server
• http//premium.itc.virginia.edu/server/
• Daily backups
• 144/GB/year small 1st time fees
• Cheap, easy, professional network administration
  for an all Microsoft OS environment
• Departmental Server
• Your depts money, staff and hardware
• Your plan, your way

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Home Directory for Depts.

• Similar deal to Premium Server
• ITC can help you decide whether to try Premium
  Server or Home Directory
• Supports access by multiple OSs
• Windows
• Mac
• Unix

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Often overlooked option

• PDAs (Personal Digital Assistants)
• Palm OS has Docs To Go and Quick Office to
  hot-synch and edit files (like this PowerPoint
  slide show)
• Pocket PC hot-synchs and edits MS Office files
• Docs To Go beats Pocket Office in preserving
  formatting after editing on Palm supports more
  Excel functions

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The rest of your data

• If you are unlikely to need or find a file,
  consider deleting it so more important files are
  easier to find
• Use WinZip (Software Central) to archive files,
  creating an intentional, minor inconvenience as a
  stage toward deletion of files
• Store on hard drive and back up.

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Current backup media

• Removable, external, large disks
• Iomega (Peerless? Jazz? HDD), Orb, etc.
• Zip
• 100MB, 250MB, 750MB
• CD-R, CD-RW
• DVD-R, -RW, R, RW, -RAM
• Tape

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External, large media

• Dont plan on buying more media later
• Standards change quickly (Peerless)
• Get media big enough to not need to swap disks
• Get at least two sets of media

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Interface for large media

• USB2 preferred for new systems
• USB1 slower, but useful
• Firewire great, but not common
• SCSI good, but aging many cables
• Parallel Just Say No
• PC Card for laptops (PCMCIA slower)
• Internal (IDE, SCSI, etc.)

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Zip

• Good for selective and differential backups
• Too small for full backups
• 100MB, 250MB, 750MB
• Works like a high-capacity diskette
• Available for most external and internal
  interfaces
• Get two sets and alternate

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CD-R, -RW

• 650MB, primarily streaming medium
• CD-RW not generically compatible with regular CD
  drives
• Two methods of use
• Project Record a batch of data files by using a
  utility designed for making a music CD
• Direct CD Spend 45 minutes formatting a disc so
  that it can be used like a diskette in Windows
• MS Backup does not recognize this medium

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Writable DVD

• 4.7GB, primarily streaming medium
• Three competing standards
• Likely one will win
• Cant tell which one
• Dont assume future availability of medium
• Dont expect disks to work in other DVD drives
• MS Backup does not recognize this medium

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Tapes

• Streaming media
• Cheap, high capacity
• Can stretch, jam, break, etc.
• Slow
• Standards change
• Get 2 sets, alternate
• Replace old tapes

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Two approaches for local files

• Selective backup
• Keeps backup small enough to be convenient to
  back up
• Possibly misses files you had not considered
• Full/Image, then Differential backup
• Less convenient, but safer
• Full works for data, not OS and applications

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Selective backup

• Like Home Directory, control where you put the
  files you will backup
• Accept that files you dont back up may
  eventually be lost
• Can be differential/incremental/full
• Try to fit available backup medium
• Swapping disks is inconvenient
• Inconvenient backups stop happening

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The Archive Bit

• Part of the OSs file system
• Set by OS when file is new or changed
• Can be read by backup software to decide which
  files to back up
• Can be cleared by backup software to mark files
  when they have been backed up
• Can be cleared or set by the ATTRIB command

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Full backup

• Ignores archive bit while selecting files
• Clears archive bit while backing up files
• Tries to back up all files within the scope of
  the backup
• Cant back up open files, so cant really back up
  OS or applications well

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Differential backup

• Works well with full backup
• Selects only files with set archive bit (not
  backed up)
• Does not clear archive bit when it backs up files
  (files still marked not backed up)
• Recovery requires most recent Full backup and
  most recent Differential backup

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Incremental backup

• Mostly useful for audit trail
• Records the evolution of each document
• Selects only files with set archive bit
• Clears archive bit while backing up
• Restore requires most recent Full backup and ALL
  incremental backups

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General Guidelines

• Alternate between media sets
• Dont destroy your only backup when you start a
  new backup
• Maybe the hard drive has a problem you dont know
  about until mid-backup
• Start with full to clear archive bit
• When differential backup gets too big, do another
  full backup

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Disk Image

• Backs up the OS and applications and all other
  files
• DCI uses a disk image for safety
• Does not interact with archive bit or work with
  differential backups
• Challenging to satisfy special hardware
  requirements

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Image beats Full

• PCs shut down slowly because files need to be
  saved to the hard drive in order to prepare for a
  good boot
• Full backups cant capture the drive in that
  boot-ready state
• Image backups capture that boot-ready state

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Disk image requirements

• Boot off a different disk (floppy, CD, Virtual
  boot partition, network)
• Access the hard drive from DOS
• Access the backup medium from DOS
• DOS drivers for the backup drive
• DOS drivers for the bus/port to the drive
• DOS drivers for the network card

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A recommended kludge

• After making an Image backup
• Open a command line window
• C
• CD\
• ATTRIB A . /S /D
• Follow with an Incremental backup to clear bit on
  hidden/system files
• Delete Incremental and use Differential

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Disk Image issues

• Requires large medium for backup
• Cant be done while machine is in use
• Requires different software from normal backups
• May require different hardware than normal
  backups
• May require DOS drivers you must find

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Disk Image software

• Image Cast
• Ghost (from Symantec, makers of Norton Utilities)
• Disk Image (by PowerQuest, makers of Partition
  Magic)

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Image Cast

• free for University-owned PCs
• https//www.web.virginia.edu/rescomp/ldb/login.asp
  
• Requires Windows 98 (or 95) boot floppy for
  stand-alone operation
• If you follow special instructions, they give you
  boot files, but no drivers for target drives or
  network
• Primarily for Network Administrators managing
  many PCs.
• Limited options for backup media DOS has to see
  the destination, you provide drivers

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Disk Image

• Created by makers of Partition Magic
• Can create destination partition if your drive is
  large enough copy to any medium later in Windows
• Provides boot files for diskettes
• Can boot off virtual drive no diskette
• Impressively fast

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Ghost

• From Symantec
• Two versions
• For network administrators
• For end users
• Similar virtual boot options
• Has drivers for USB, SCSI, Firewire, Zip, Jazz,
  etc.

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Other backup software

• MS Backup comes with Windows
• Other backup media often supply backup software
  with the hardware
• Third party backup software is also available
• Offers more backup options
• Most people dont need these options

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Is there a sane approach?

• DCI gives you a disk image safety net
• If you need more current safety nets, look into
  disk image software and expect technical issues
• Image your drive before and after significant
  software/hardware changes
• Use other backup types for current data

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Additional advice

• Image with attrib is better than Full
• You can make differential to network or backup
  partition, then copy to CD-RW
• Dont make differential to C, creating a loop
  backing up the backup file
• Always alternate between two sets

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Related Web site

• http//www.itc.virginia.edu/desktop/pc/backup

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Remember

• Make the backup youll wish you made before you
  wish you made it.