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diff --git a/sag-0.6.1-www/sag-0.6.1.html/x2216.html b/sag-0.6.1-www/sag-0.6.1.html/x2216.html new file mode 100644 index 0000000..d64dca4 --- /dev/null +++ b/sag-0.6.1-www/sag-0.6.1.html/x2216.html @@ -0,0 +1,226 @@ +<!DOCTYPE HTML PUBLIC "-//Norman Walsh//DTD DocBook HTML 1.0//EN"> +<HTML +><HEAD +><TITLE +>Selecting the backup tool</TITLE +><META +NAME="GENERATOR" +CONTENT="Modular DocBook HTML Stylesheet"><LINK +REL="HOME" +TITLE="The Linux System Administrators' Guide" +HREF="book1.html"><LINK +REL="UP" +TITLE="Backups" +HREF="c2187.html"><LINK +REL="PREVIOUS" +TITLE="Selecting the backup medium" +HREF="x2206.html"><LINK +REL="NEXT" +TITLE="Simple backups" +HREF="x2240.html"></HEAD +><BODY +BGCOLOR="#FFFFFF" +TEXT="#000000" +><DIV +CLASS="NAVHEADER" +><TABLE +WIDTH="100%" +BORDER="0" +CELLPADDING="0" +CELLSPACING="0" +><TR +><TH +COLSPAN="3" +ALIGN="center" +>The Linux System Administrators' Guide</TH +></TR +><TR +><TD +WIDTH="10%" +ALIGN="left" +VALIGN="bottom" +><A +HREF="x2206.html" +>Prev</A +></TD +><TD +WIDTH="80%" +ALIGN="center" +VALIGN="bottom" +>Chapter 10. Backups</TD +><TD +WIDTH="10%" +ALIGN="right" +VALIGN="bottom" +><A +HREF="x2240.html" +>Next</A +></TD +></TR +></TABLE +><HR +ALIGN="LEFT" +WIDTH="100%"></DIV +><DIV +CLASS="SECT1" +><H1 +CLASS="SECT1" +><A +NAME="AEN2216" +>Selecting the backup tool</A +></H1 +><P +> There are many tools that can be used to make + backups. The traditional UNIX tools used for backups + are <B +CLASS="COMMAND" +>tar</B +>, <B +CLASS="COMMAND" +>cpio</B +>, and + <B +CLASS="COMMAND" +>dump</B +>. In addition, there are large number + of third party packages (both freeware and commercial) that + can be used. The choice of backup medium can affect the choice + of tool. </P +><P +> <B +CLASS="COMMAND" +>tar</B +> and <B +CLASS="COMMAND" +>cpio</B +> are + similar, and mostly equivalent from a backup point of view. + Both are capable of storing files on tapes, and retrieving + files from them. Both are capable of using almost any media, + since the kernel device drivers take care of the low level + device handling and the devices all tend to look alike to user + level programs. Some UNIX versions of <B +CLASS="COMMAND" +>tar</B +> + and <B +CLASS="COMMAND" +>cpio</B +> may have problems with unusual files + (symbolic links, device files, files with very long pathnames, and + so on), but the Linux versions should handle all files correctly. + </P +><P +> <B +CLASS="COMMAND" +>dump</B +> is different in that it reads + the filesystem directly and not via the filesystem. It is + also written specifically for backups; <B +CLASS="COMMAND" +>tar</B +> + and <B +CLASS="COMMAND" +>cpio</B +> are really for archiving files, + although they work for backups as well. </P +><P +> Reading the filesystem directly has some advantages. + It makes it possible to back files up without affecting their time + stamps; for <B +CLASS="COMMAND" +>tar</B +> and <B +CLASS="COMMAND" +>cpio</B +>, + you would have to mount the filesystem read-only first. + Directly reading the filesystem is also more effective, if + everything needs to be backed up, since it can be done with + much less disk head movement. The major disadvantage is that + it makes the backup program specific to one filesystem type; + the Linux <B +CLASS="COMMAND" +>dump</B +> program understands the ext2 + filesystem only. </P +><P +> <B +CLASS="COMMAND" +>dump</B +> also directly supports + backup levels (which we'll be discussing below); with + <B +CLASS="COMMAND" +>tar</B +> and <B +CLASS="COMMAND" +>cpio</B +> this has to + be implemented with other tools. </P +><P +> A comparison of the third party backup tools is beyond + the scope of this book. The Linux Software Map lists many of + the freeware ones. </P +></DIV +><DIV +CLASS="NAVFOOTER" +><HR +ALIGN="LEFT" +WIDTH="100%"><TABLE +WIDTH="100%" +BORDER="0" +CELLPADDING="0" +CELLSPACING="0" +><TR +><TD +WIDTH="33%" +ALIGN="left" +VALIGN="top" +><A +HREF="x2206.html" +>Prev</A +></TD +><TD +WIDTH="34%" +ALIGN="center" +VALIGN="top" +><A +HREF="book1.html" +>Home</A +></TD +><TD +WIDTH="33%" +ALIGN="right" +VALIGN="top" +><A +HREF="x2240.html" +>Next</A +></TD +></TR +><TR +><TD +WIDTH="33%" +ALIGN="left" +VALIGN="top" +>Selecting the backup medium</TD +><TD +WIDTH="34%" +ALIGN="center" +VALIGN="top" +><A +HREF="c2187.html" +>Up</A +></TD +><TD +WIDTH="33%" +ALIGN="right" +VALIGN="top" +>Simple backups</TD +></TR +></TABLE +></DIV +></BODY +></HTML +>
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