summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorben <ben@2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109>2002-09-11 06:22:51 +0000
committerben <ben@2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109>2002-09-11 06:22:51 +0000
commit87a55279ef562b8348d796ca81d76e249ec534a8 (patch)
tree7d478fa23bbc9b10a840639bdb8052cc1e145b3e
parent68701e882be9cff70f1ab814a1a2fb738ac0dac6 (diff)
downloadrdiff-backup-87a55279ef562b8348d796ca81d76e249ec534a8.tar.gz
Finally added FAQ.wml file.
git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup/trunk@199 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109
-rw-r--r--rdiff-backup/FAQ.wml351
1 files changed, 351 insertions, 0 deletions
diff --git a/rdiff-backup/FAQ.wml b/rdiff-backup/FAQ.wml
new file mode 100644
index 0000000..c7065e4
--- /dev/null
+++ b/rdiff-backup/FAQ.wml
@@ -0,0 +1,351 @@
+#include 'template.wml' curpage=faq title="rdiff-backup: FAQ"
+
+<divert body>
+<p><h2>FAQ:</h2>
+
+<h3>Table of contents</h3>
+
+<ol><li><a href="#__future__">When I try to run rdiff-backup it says
+"ImportError: No module named __future__" or "SyntaxError: invalid
+syntax". What's happening?</a></li>
+
+<li><a href="#verbosity">What do the different verbosity levels mean?</a></li>
+
+<li><a href="#windows">Does rdiff-backup run under Windows?</a></li>
+
+<li><a href="#remove_dir">My backup set contains some files that I just realized I don't want/need backed up. How do I remove them from the backup volume to save space?</li>
+
+<li><a href="#redhat">How do I install the RPMs on Redhat linux system?</a></li>
+
+<li><a href="#solaris">Does rdiff-backup work under Solaris?</a></li>
+
+<li><a href="#speed">How fast is rdiff-backup? Can it be run on large
+data sets?</a></li>
+
+<li><a href="#statistics">What do the various fields mean in the
+session statistics and directory statistics files?</a></li>
+
+<li><a href="#bwlimit">Is there some way to limit rdiff-backup's
+bandwidth usage, as in rsync's --bwlimit option?</a></li>
+
+</ol>
+
+<h3>Questions and Answers</h3>
+
+<ol>
+
+<a name="__future__">
+<li><strong>When I try to run rdiff-backup it says "ImportError: No
+module named __future__" or "SyntaxError: invalid syntax". What's
+happening?</strong>
+
+<P>rdiff-backup versions 0.2.x require Python version 2.1 or later,
+and versions 0.3.x and later require Python version 2.2 or later. If
+you don't know what version of python you are running, type in "python
+-V" from the shell. I'm sorry if this is inconvenient, but
+rdiff-backup uses generators, iterators, nested scoping, and
+static/class methods extensively, and these were only added in version
+2.2.
+
+<P>If you have two versions of python installed, and running "python"
+defaults to an early version, you'll probably have to change the first
+line of the rdiff-backup script. For instance, you could set it to:
+
+<pre>#!/usr/bin/env python2.2</pre>
+</li>
+
+<a name="verbosity">
+<li><strong>What do the different verbosity levels mean?</strong>
+
+<P>There is no formal specification, but here is a rough description
+(settings are always cumulative, so 5 displays everything 4 does):
+
+<P>
+<table cellspacing="10">
+<tr><td>0</td><td>No information given</td></tr>
+<tr><td>1</td><td>Fatal Errors displayed</td></tr>
+<tr><td>2</td><td>Warnings</td></tr>
+<tr><td>3</td><td>Important messages, and maybe later some global statistics (default)</td></tr>
+<tr><td>4</td><td>Some global settings, miscellaneous messages</td></tr>
+<tr><td>5</td><td>Mentions which files were changed</td></tr>
+<tr><td>6</td><td>More information on each file processed</td></tr>
+<tr><td>7</td><td>More information on various things</td></tr>
+<tr><td>8</td><td>All logging is dated</td></tr>
+<tr><td>9</td><td>Details on which objects are moving across the connection</td></tr>
+</table>
+
+<a name="windows">
+<li><strong>Does rdiff-backup run under Windows?</strong>
+
+<P>Yes, apparently it is possible. First, follow Jason Piterak's
+instructions:
+
+<pre>
+Subject: Cygwin rdiff-backup
+From: Jason Piterak &lt;Jason_Piterak@c-i-s.com&gt;
+Date: Mon, 4 Feb 2002 16:54:24 -0500 (13:54 PST)
+To: rdiff-backup@keywest.Stanford.EDU
+
+Hello all,
+ On a lark, I thought I would attempt to get rdiff-backup to work under
+Windows98 under Cygwin. We have a number of NT/Win2K servers in the field
+that I'd love to be backing up via rdiff-backup, and this was the start of
+getting that working.
+
+SUMMARY:
+ o You can get all the pieces for rdiff-backup working under Cygwin.
+ o The backup process works up to the point of writing any files with
+timestamps.
+ ... This is because the ':' character is reserved for Alternate Data
+Stream (ADS) file designations under NTFS.
+
+HOW TO GET IT WORKING (to a point, anyway):
+ o Install Cygwin
+ o Download the Python 2.2 update through the Cygwin installer and install.
+ o Download the librsync libraries from the usual place, but before
+compiling...
+ o Cygwin does not use/provide glibc. Because of this, you have to repoint
+some header files in the Makefile:
+
+ -- Make sure that you have /usr/include/inttypes.h
+ redirected to /usr/include/sys/types.h. Do this by:
+
+ create a file /usr/include/inttypes.h with the contents:
+ #include &lt;sys/types.h&gt;
+ o Put rdiff-backup in your PATH, as you normally would.
+
+</pre>
+
+Then, whenever you use rdiff-backup (or at least if you are backing up
+to or restoring from a Windows system), use the
+<strong>--windows-time-format</strong> switch, which will tell
+rdiff-backup not to put a colon (":") in a filename (this option was
+added after Jason posted his message). Finally, as Michael Muegel
+points out, you have to exclude all files from the source directory
+which have colons in them, so add something like the --exclude ".*:.*"
+option. In the near future some quoting facility may be added to deal
+with these issues.
+</li>
+
+<P>
+<a name="remove_dir">
+<li><strong>My backup set contains some files that I just realized I
+don't want/need backed up. How do I remove them from the backup
+volume to save space?</strong>
+
+<P>Let's take an example. Suppose you ran
+<pre>rdiff-backup /usr /backup</pre>
+and now realize that you don't want /usr/local backed up on /backup.
+Next time you back up, you run
+<pre>rdiff-backup --exclude /usr/local /usr /backup</pre>
+so that /usr/local is no longer copied to /backup/usr/local.
+
+However, old information about /usr/local is still present in
+/backup/rdiff-backup-data/increments/usr/local. You could wait for
+this information to expire and then run rdiff-backup with the
+--remove-older-than option, or you could remove the increments
+manually by typing:
+<pre>rm -rf /backup/rdiff-backup-data/increments/usr/local
+rm /backup/rdiff-backup-data/increments/usr/local.*.dir</pre>
+
+</li>
+
+<P>
+<a name="redhat">
+<li><strong>How do I install the RPMs on a Redhat linux system?</strong>
+
+<P>The problem is that the default version of python for Redhat 7.x is
+1.5.x, and rdiff-backup requires python >= 2.2. Redhat/rawhide
+provides python 2.2 RPMs, but they are packaged under the "python2"
+name.
+
+<P>So, if you are running Redhat 7.x:
+
+<ol>
+<li>Make sure the python2 >= 2.2 package is installed,
+leaving python 1.5 the way it is
+<li>Install the rdiff-backup RPM, using --nodeps if it only complains
+ about python 2.2 missing.
+<li>Edit the first line of /usr/bin/rdiff-backup so it says<pre>
+#!/usr/bin/env python2
+</pre>
+so "python2" gets run instead of "python".
+</ol>
+
+<P>You can also upgrade using a non-Redhat python 2.2 RPM and avoid
+the above steps (this is what I did). Because of all the dependencies
+it is usually easier to use source RPMs for this.
+</li>
+
+<P>
+<a name="solaris">
+<li><strong>Does rdiff-backup work under Solaris?</strong>
+
+<P>There may be a problem with rdiff-backup and Solaris' libthread.
+Adding "ulimit -n unlimited" may fix the problem though. Here is a
+post by Kevin Spicer on the subject:
+
+<pre>
+Subject: RE: Crash report....still not^H^H^H working
+From: "Spicer, Kevin" <Kevin.Spicer@bmrb.co.uk>
+Date: Sat, 11 May 2002 23:36:42 +0100
+To: rdiff-backup@keywest.Stanford.EDU
+
+Quick mail to follow up on this..
+My rdiff backup (on Solaris 2.6 if you remember) has now worked
+reliably for nearly two weeks after I added...
+
+ ulimit -n unlimited
+
+to the start of my cron job and created a wrapper script on the remote
+machine which looked like this...
+
+ #!/bin/sh
+ ulimit -n unlimited
+ rdiff-backup --server
+ exit
+
+And changed the remote schema on the command line of rdiff-backup to
+call the wrapper script rather than rdiff-backup itself on the remote
+machine. As for the /dev/zero thing I've done a bit of Googleing and
+it seems that /dev/zero is used internally by libthread on Solaris
+(which doesn't really explain why its opening more than 64 files - but
+at least I think I've now got round it).
+</pre>
+</li>
+
+<P>
+<a name="speed">
+<li><strong>How fast is rdiff-backup? Can it be run on large
+data sets?</strong>
+
+<P>rdiff-backup can be limited by the CPU, disk IO, or available
+bandwidth, and the length of a session can be affected by the amount
+of data, how much the data changed, and how many files are present.
+That said, in the typical case the number/size of changed files is
+relatively small compared to that of unchanged files, and rdiff-backup
+is often either CPU or bandwidth bound, and takes time proportional to
+the total number of files. Initial mirrorings will usually be
+bandwidth or disk bound, and will take much longer than subsequent
+updates.
+
+<P>To give two arbitrary data points, when I back up my personal HD
+locally (about 9GB, 600000 files, maybe 50 MB turnover, 1.1Ghz athlon)
+rdiff-backup takes about 35 minutes and is usually CPU bound. Another
+user reports an rdiff-backup session takes about 3 hours (80GB, ~1mil
+files, 2GB turnover) to back up remotely Tru64 -> linux.
+</li>
+
+<p>
+<a name="statistics">
+<li><strong>What do the various fields mean in the
+session statistics and directory statistics files?</strong>
+
+<P>Let's examine an example session statistics file:
+
+<pre>
+StartTime 1028200920.44 (Thu Aug 1 04:22:00 2002)
+EndTime 1028203082.77 (Thu Aug 1 04:58:02 2002)
+ElapsedTime 2162.33 (36 minutes 2.33 seconds)
+SourceFiles 494619
+SourceFileSize 8535991560 (7.95 GB)
+MirrorFiles 493797
+MirrorFileSize 8521756994 (7.94 GB)
+NewFiles 1053
+NewFileSize 23601632 (22.5 MB)
+DeletedFiles 231
+DeletedFileSize 10346238 (9.87 MB)
+ChangedFiles 572
+ChangedSourceSize 86207321 (82.2 MB)
+ChangedMirrorSize 85228149 (81.3 MB)
+IncrementFiles 1857
+IncrementFileSize 13799799 (13.2 MB)
+TotalDestinationSizeChange 28034365 (26.7 MB)
+Errors 0
+</pre>
+
+<P>StartTime and EndTime are measured in seconds since the epoch.
+ElapsedTime is just EndTime - StartTime, the length of the
+rdiff-backup session.
+
+<P>SourceFiles are the number of files found in the source directory,
+and SourceFileSize is the total size of those files. MirrorFiles are
+the number of files found in the mirror directory (not including the
+rdiff-backup-data directory) and MirrorFileSize is the total size of
+those files. All sizes are in bytes. If the source directory hasn't
+changed since the last backup, MirrorFiles == SourceFiles and
+SourceFileSize == MirrorFileSize.
+
+<P>NewFiles and NewFileSize are the total number and size of the files
+found in the source directory but not in the mirror directory. They
+are new as of the last backup.
+
+<P>DeletedFiles and DeletedFileSize are the total number and size of
+the files found in the mirror directory but not the source directory.
+They have been deleted since the last backup.
+
+<P>ChangedFiles are the number of files that exist both on the mirror
+and on the source directories and have changed since the previous
+backup. ChangedSourceSize is their total size on the source
+directory, and ChangedMirrorSize is their total size on the mirror
+directory.
+
+<P>IncrementFiles is the number of increment files written to the
+rdiff-backup-data directory, and IncrementFileSize is their total
+size. Generally one increment file will be written for every new,
+deleted, and changed file.
+
+<P>TotalDestinationSizeChange is the number of bytes the destination
+directory as a whole (mirror portion and rdiff-backup-data directory)
+has grown during the given rdiff-backup session. This is usually
+close to IncrementFileSize + NewFileSize - DeletedFileSize +
+ChangedSourceSize - ChangedMirrorSize, but it also includes the space
+taken up by the hardlink_data file to record hard links.
+</li>
+
+<a name="bwlimit">
+<li><strong>Is there some way to limit rdiff-backup's
+bandwidth usage, as in rsync's --bwlimit option?</strong>
+
+<P>There is no internal rdiff-backup option to do this. However, the
+--sleep-ratio option can limit overall resource usage, including
+bandwidth. Also, external utilities such as <a href="http://www.cons.org/cracauer/cstream.html">cstream</a> can be
+used to monitor bandwidth explicitly. trevor@tecnopolis.ca writes:
+
+<pre>
+rdiff-backup --remote-schema
+ 'cstream -v 1 -t 10000 | ssh %s '\''rdiff-backup --server'\'' | cstream -t 20000'
+ 'netbak@foo.bar.com::/mnt/backup' localbakdir
+
+(must run from a bsh-type shell, not a csh type)
+
+That would apply a limit in both directions [10000 bytes/sec outgoing,
+20000 bytes/sec incoming]. I don't think you'd ever really want to do
+this though as really you just want to limit it in one direction.
+Also, note how I only -v 1 in one direction. You probably don't want
+to output stats for both directions as it will confuse whatever script
+you have parsing the output. I guess it wouldn't hurt for manual runs
+however.
+</pre>
+
+To only limit bandwidth in one directory, simply remove one of the
+cstream commands. Two cstream caveats may be worth mentioning:
+
+<ol> <li>Because cstream is limiting the uncompressed data heading
+into or out of ssh, if ssh compression is turned on, cstream may be
+overly restrictive.</li>
+
+<li>cstream may be "bursty", limiting average bandwidth but allowing
+rdiff-backup to exceed it for significant periods.</li>
+
+</ol>
+
+Another option is to limit bandwidth at a lower (and perhaps more
+appropriate) level. Adam Lazur suggests <a
+href="http://lartc.org/wondershaper/">The Wonder Shaper</a>.
+
+</li>
+
+</ol>
+
+</divert>