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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node100.html b/sag-0.6.1-www/Invisible/sag-0.6/node100.html new file mode 100644 index 0000000..d8d2c7b --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node100.html @@ -0,0 +1,67 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> +<!--Converted with LaTeX2HTML 96.1-h (September 30, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> +<HTML> +<HEAD> +<TITLE>Simple backups</TITLE> +<META NAME="description" CONTENT="Simple backups"> +<META NAME="keywords" CONTENT="sag"> +<META NAME="resource-type" CONTENT="document"> +<META NAME="distribution" CONTENT="global"> +<LINK REL=STYLESHEET HREF="sag.css"> +</HEAD> +<BODY LANG="EN" > + <A NAME="tex2html1577" HREF="node101.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1575" HREF="node96.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1569" HREF="node99.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1579" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1580" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1578" HREF="node101.html">Making backups with tar</A> +<B>Up:</B> <A NAME="tex2html1576" HREF="node96.html">Backups</A> +<B> Previous:</B> <A NAME="tex2html1570" HREF="node99.html">Selecting the backup tool</A> +<BR> <P> +<H1><A NAME="SECTION001140000000000000000">Simple backups</A></H1> +<P> + A simple backup scheme is to back up everything once, then back + up everything that has been modified since the previous backup. + The first backup is called a <b>full backup</b>, the subsequent + ones are <b>incremental backups</b>. A full backup is often + more laborius than incremental ones, since there is more data + to write to the tape and a full backup might not fit onto one + tape (or floppy). Restoring from incremental backups can be + many times more work than from a full one. Restoration + can be optimized so that you always back up everything since the + previous full backup; this way, backups are a bit more work, + but there should never be a need to restore more than a full + backup and an incremental backup. +<P> + If you want to make backups every day and have six tapes, you could + use tape 1 for the first full backup (say, on a Friday), and + tapes 2 to 5 for the incremental backups (Monday through Thursday). + Then you make a new full backup on tape 6 (second Friday), + and start doing incremental ones with + tapes 2-5 again. You don't want to overwrite tape 1 with + until you've got a new full backup, lest something happens + while you're making the full backup. After you've made a + full backup to tape 6, you want to keep tape 1 somewhere + else, so that when your other backup tapes are destroyed in + the fire, you still have at least something left. When you + need to make the next full backup, you fetch tape 1 and leave + tape 6 in its place. +<P> + If you have more than six tapes, you can use the extra ones for + full backups. Each time you make a full backup, you use the oldest + tape. This way you can have full backups from several previous + weeks, which is good if you want to find an old, now deleted file, + or an old version of a file. +<P> +<BR> <HR> +<UL><A NAME="CHILD_LINKS"> </A> +<LI> <A NAME="tex2html1581" HREF="node101.html#SECTION001141000000000000000">Making backups with <tt>tar</tt></A> +<LI> <A NAME="tex2html1582" HREF="node102.html#SECTION001142000000000000000">Restoring files with <tt>tar</tt></A> +</UL> +<HR><A NAME="tex2html1577" HREF="node101.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1575" HREF="node96.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1569" HREF="node99.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1579" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1580" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1578" HREF="node101.html">Making backups with tar</A> +<B>Up:</B> <A NAME="tex2html1576" HREF="node96.html">Backups</A> +<B> Previous:</B> <A NAME="tex2html1570" HREF="node99.html">Selecting the backup tool</A> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |