154 lines
5.9 KiB
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154 lines
5.9 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
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<META NAME="GENERATOR" CONTENT="SGML-Tools 1.0.9">
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<TITLE>HOWTO: Multi Disk System Tuning: Concluding Remarks</TITLE>
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<LINK HREF="Multi-Disk-HOWTO-19.html" REL=next>
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<LINK HREF="Multi-Disk-HOWTO-17.html" REL=previous>
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<LINK HREF="Multi-Disk-HOWTO.html#toc18" REL=contents>
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<BODY>
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<A HREF="Multi-Disk-HOWTO-19.html">Next</A>
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<A HREF="Multi-Disk-HOWTO-17.html">Previous</A>
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<A HREF="Multi-Disk-HOWTO.html#toc18">Contents</A>
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<HR>
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<H2><A NAME="s18">18. Concluding Remarks</A></H2>
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<P>
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<!--
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disk!conclusion
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-->
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Disk tuning and partition decisions are difficult to make, and there are no
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hard rules here. Nevertheless it is a good idea to work more on this as the
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payoffs can be considerable. Maximizing usage on one drive only while the
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others are idle is unlikely to be optimal, watch the drive light, they are
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not there just for decoration. For a properly set up system the lights should
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look like Christmas in a disco. Linux offers software RAID but also support
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for some hardware base SCSI RAID controllers. Check what is available. As
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your system and experiences evolve you are likely to repartition and you
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might look on this document again. Additions are always welcome.
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<P>Finally I'd like to sum up my recommendations:
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<UL>
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<LI>Disks are cheap but the data they contain could be much more
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valuable, use and test your backup system.</LI>
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<LI>Work is also expensive, make sure you get large enough disks
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as refitting new or repartitioning old disks takes time.</LI>
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<LI>Think reliability, replace old disks before they fail.</LI>
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<LI>Keep a paper copy of your setup, having it all on disk when
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the machine is down will not help you much.</LI>
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<LI>Start out with a simple design with a minimum of fancy technology
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and rather fit it in later. In general adding is easier than replacing,
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be it disks, technology or other features.</LI>
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</UL>
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<P>
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<P>
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<H2><A NAME="ss18.1">18.1 Coming Soon</A>
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</H2>
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<P>
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<!--
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disk!coming soon
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There are a few more important things that are about to appear here. In
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particular I will add more example tables as I am about to set
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up two fairly large and general systems, one at work and one at home. These
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should give some general feeling on how a system can be set up for either
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of these two purposes. Examples of smooth running existing systems are
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also welcome.
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<P>There is also a fair bit of work left to do on the various kinds of file
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systems and utilities.
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<P>There will be a big addition on drive technologies coming soon
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as well as a more in depth description on using
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<CODE>fdisk</CODE>, <CODE>cfdisk</CODE> and <CODE>sfdisk</CODE>.
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The file systems will be beefed up as more features become available
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as well as more on RAID and what directories can benefit from what
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RAID level.
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<P>
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<P>There is some minor overlapping with
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the Linux Filesystem Structure Standard and FHS
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that I hope to integrate better soon, which will
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probably mean a big reworking
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of all the tables at the end of this document.
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<P>As more people start reading this I should get some more
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comments and feedback. I am also thinking of making a program
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that can automate a fair bit of this decision making process
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and although it is unlikely to be optimum it should provide
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a simpler, more complete starting point.
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<P>
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<H2><A NAME="ss18.2">18.2 Request for Information</A>
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</H2>
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<P>
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<!--
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disk!request for information
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-->
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It has taken a fair bit of time to write this document and although
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most pieces are beginning to come together there are still some
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information needed before we are out of the beta stage.
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<P>
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<UL>
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<LI> More information on swap sizing policies is needed as well as
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information on the largest swap size possible under the various kernel
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versions.</LI>
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<LI> How common is drive or file system corruption? So far I have
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only heard of problems caused by flaky hardware.</LI>
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<LI> References to speed and drives is needed.</LI>
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<LI> Are any other Linux compatible RAID controllers available?</LI>
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<LI> What relevant monitoring, management and maintenance
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tools are available?</LI>
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<LI> General references to information sources are needed, perhaps
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this should be a separate document?</LI>
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<LI> Usage of <CODE>/tmp</CODE> and <CODE>/var/tmp</CODE> has been hard to
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determine, in fact what programs use which directory is not well defined
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and more information here is required. Still, it seems at least clear
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that these should reside on different physical drives in order to increase
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paralellicity.</LI>
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</UL>
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<P>
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<H2><A NAME="ss18.3">18.3 Suggested Project Work</A>
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</H2>
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<P>
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<!--
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disk!projects, suggested
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-->
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Now and then people post on comp.os.linux.*, looking for good project
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ideas. Here I will list a few that comes to mind that are relevant to
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this document. Plans about big projects such as new file systems should
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still be posted in order to either find co-workers or see if someone is
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already working on it.
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<P>
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<DL>
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<P>
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<DT><B>Planning tools</B><DD><P>that can automate the design process outlines
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earlier would probably make a medium sized project, perhaps as an
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exercise in constraint based programming.
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<P>
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<DT><B>Partitioning tools</B><DD><P>that take the output of the previously
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mentioned program and format drives in parallel and apply the
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appropriate symbolic links to the directory structure. It would
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probably be best if this were integrated in existing system
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installation software. The drive partitioning setup used in
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Solaris is an example of what it can look like.
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<P>
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<DT><B>Surveillance tools</B><DD><P>that keep an eye on the partition sizes
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and warn before a partition overflows.
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<P>
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<DT><B>Migration tools</B><DD><P>that safely lets you move old structures to
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new (for instance RAID) systems. This could probably be done as a
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shell script controlling a back up program and would be rather
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simple. Still, be sure it is safe and that the changes can be undone.
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<P>
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</DL>
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<P>
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<HR>
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<A HREF="Multi-Disk-HOWTO-19.html">Next</A>
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<A HREF="Multi-Disk-HOWTO-17.html">Previous</A>
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<A HREF="Multi-Disk-HOWTO.html#toc18">Contents</A>
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