186 lines
4.1 KiB
HTML
186 lines
4.1 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>On the importance of being backed up</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="Linux System Administrators Guide"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Backups"
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HREF="backups-intro.html"><LINK
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REL="PREVIOUS"
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TITLE="Backups"
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HREF="backups-intro.html"><LINK
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REL="NEXT"
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TITLE="Selecting the backup medium"
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HREF="backup-media.html"></HEAD
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><BODY
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CLASS="SECT1"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>Linux System Administrators Guide: </TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="backups-intro.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Chapter 12. Backups</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="backup-media.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="SECT1"
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><H1
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CLASS="SECT1"
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><A
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NAME="BACKUPS"
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></A
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>12.1. On the importance of being backed up</H1
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><P
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> Your data is valuable. It will cost you time and effort
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re-create it, and that costs money or at least personal grief
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and tears; sometimes it can't even be re-created, e.g., if it
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is the results of some experiments. Since it is an investment,
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you should protect it and take steps to avoid losing it. </P
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><P
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> There are basically four reasons why you might lose data:
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hardware failures, software bugs, human action, or natural
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disasters. Although modern hardware tends to be quite reliable, it
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can still break seemingly spontaneously. The most critical piece
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of hardware for storing data is the hard disk, which relies on
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tiny magnetic fields remaining intact in a world filled with
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electromagnetic noise. Modern software doesn't even tend to
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be reliable; a rock solid program is an exception, not a rule.
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Humans are quite unreliable, they will either make a mistake, or
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they will be malicious and destroy data on purpose. Nature might
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not be evil, but it can wreak havoc even when being good. All in
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all, it is a small miracle that anything works at all. </P
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><P
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> Backups are a way to protect the investment in data.
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By having several copies of the data, it does not matter as much
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if one is destroyed (the cost is only that of the restoration
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of the lost data from the backup). </P
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><P
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> It is important to do backups properly. Like everything
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else that is related to the physical world, backups will fail
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sooner or later. Part of doing backups well is to make sure
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they work; you don't want to notice that your backups didn't work.
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Adding insult to injury, you might have a bad crash just as
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you're making the backup; if you have only one backup medium,
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it might destroyed as well, leaving you with the smoking ashes
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of hard work.
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Or you might notice, when trying to restore, that you forgot to
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back up something important, like the user database on a 15000
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user site. Best of all, all your backups might be working
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perfectly, but the last known tape drive reading the kind of
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tapes you used was the one that now has a bucketful of water
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in it. </P
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><P
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> When it comes to backups, paranoia is in the job
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description. </P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="backups-intro.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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ACCESSKEY="H"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="backup-media.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Backups</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="backups-intro.html"
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ACCESSKEY="U"
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>Up</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>Selecting the backup medium</TD
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></TR
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></TABLE
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></DIV
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></BODY
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></HTML
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> |