190 lines
4.1 KiB
HTML
190 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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>Selecting the backup medium</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="On the importance of being backed up"
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HREF="backups.html"><LINK
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REL="NEXT"
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TITLE="Selecting the backup tool"
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HREF="backup-tools.html"></HEAD
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><TR
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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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HREF="backups.html"
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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-tools.html"
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>Next</A
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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="BACKUP-MEDIA"
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></A
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>12.2. Selecting the backup medium</H1
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><P
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> The most important decision regarding backups is the choice
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of backup medium. You need to consider cost, reliability, speed,
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availability, and usability. </P
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><P
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> Cost is important, since you should preferably have
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several times more backup storage than what you need for the data.
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A cheap medium is usually a must. </P
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><P
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> Reliability is extremely important, since a broken
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backup can make a grown man cry. A backup medium must be able
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to hold data without corruption for years. The way you use the
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medium affects it reliability as a backup medium. A hard disk
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is typically very reliable, but as a backup medium it is not
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very reliable, if it is in the same computer as the disk you
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are backing up. </P
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><P
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> Speed is usually not very important, if backups can be done
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without interaction. It doesn't matter if a backup takes two
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hours, as long as it needs no supervision. On the other hand,
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if the backup can't be done when the computer would otherwise
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be idle, then speed is an issue. </P
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><P
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> Availability is obviously necessary, since you can't
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use a backup medium if it doesn't exist. Less obvious is the
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need for the medium to be available even in the future, and on
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computers other than your own. Otherwise you may not be able
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to restore your backups after a disaster. </P
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><P
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> Usability is a large factor in how often backups are made.
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The easier it is to make backups, the better. A backup medium
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mustn't be hard or boring to use. </P
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><P
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> The typical alternatives are floppies and tapes.
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Floppies are very cheap, fairly reliable, not very fast,
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very available, but not very usable for large amounts of data.
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Tapes are cheap to somewhat expensive, fairly reliable, fairly
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fast, quite available, and, depending on the size of the tape,
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quite comfortable. </P
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><P
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> There are other alternatives. They are usually not very
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good on availability, but if that is not a problem, they can
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be better in other ways. For example, magneto-optical disks
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can have good sides of both floppies (they're random access,
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making restoration of a single file quick) and tapes (contain
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a lot of data). </P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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ALIGN="LEFT"
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SUMMARY="Footer navigation table"
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><TR
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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.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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WIDTH="34%"
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VALIGN="top"
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HREF="index.html"
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>Home</A
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VALIGN="top"
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><A
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HREF="backup-tools.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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>On the importance of being backed up</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 tool</TD
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></TR
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></TABLE
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></DIV
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> |