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author | ben <ben@2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109> | 2002-09-11 16:26:43 +0000 |
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committer | ben <ben@2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109> | 2002-09-11 16:26:43 +0000 |
commit | 8ba5c6d14853866f450132393dc87764286639f2 (patch) | |
tree | 9395cf32fc2fad3886956ecdbf37e3ceaa7740f1 /rdiff-backup/FAQ-body.html | |
parent | 58ef11f8f55b14c1a80e650bf7d38dffd1fd77a9 (diff) | |
download | rdiff-backup-8ba5c6d14853866f450132393dc87764286639f2.tar.gz |
Realized FAQ-body, not FAQ.wml should be in cvs
git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup/trunk@201 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109
Diffstat (limited to 'rdiff-backup/FAQ-body.html')
-rw-r--r-- | rdiff-backup/FAQ-body.html | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/rdiff-backup/FAQ-body.html b/rdiff-backup/FAQ-body.html index cdc4061..4c03a47 100644 --- a/rdiff-backup/FAQ-body.html +++ b/rdiff-backup/FAQ-body.html @@ -17,6 +17,12 @@ syntax". What's happening?</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> @@ -223,5 +229,117 @@ 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> + +<p> +Another option is to limit bandwidth at a lower (and perhaps more +appropriate) level. Adam Lazur mentions <a +href="http://lartc.org/wondershaper/">The Wonder Shaper</a>. + +</li> + +</ol> + |