-<!-- Section2: logical-struct -->
-
- <sect2 id="logical-struct">
- <title>Logical structure</title>
-
- <indexterm>
- <primary>disk!structure, I/O subsystem</primary>
- </indexterm>
-
- <para>
- This is based on how each layer access each other, traditionally
- with the application on top and the physical layer on the bottom.
- It is quite useful to show the interrelationship between each of
- the layers used in controlling drives.
-
- <screen>
- ___________________________________________________________
- |__ File structure ( /usr /tmp etc) __|
- |__ File system (ext2fs, vfat etc) __|
- |__ Volume management (AFS) __|
- |__ RAID, concatenation (md) __|
- |__ Device driver (SCSI, IDE etc) __|
- |__ Controller (chip, card) __|
- |__ Connection (cable, network) __|
- |__ Drive (magnetic, optical etc) __|
- -----------------------------------------------------------
- </screen>
- </para>
-
- <para>
- In the above diagram both volume management and RAID and
- concatenation are optional layers. The 3 lower layers are in
- hardware. All parts are discussed at length later on in this
- document.
- </para>
- </sect2>
-
-<!-- Section2: doc-struct -->
-
- <sect2 id="doc-struct">
- <title>Document structure</title>
-
- <para>
- Most users start out with a given set of hardware and some plans
- on what they wish to achieve and how big the system should be.
- This is the point of view I will adopt in this document in
- presenting the material, starting out with hardware, continuing
- with design constraints before detailing the design strategy that
- I have found to work well. I have used this both for my own
- personal computer at home, a multi purpose server at work and
- found it worked quite well. In addition my Japanese co-worker in
- this project have applied the same strategy on a server in an
- academic setting with similar success.
- </para>
-
- <para>
- Finally at the end I have detailed some configuration tables for
- use in your own design. If you have any comments regarding this
- or notes from your own design work I would like to hear from you
- so this document can be upgraded.
- </para>
- </sect2>
-
-<!-- Section2: reading-plan -->
-
- <sect2 id="reading-plan">
- <title>Reading plan</title>
-
- <para>
- <emphasis>As you go beyond 50 pages or so there will be a lot of
- text that experts and even the experienced do not need to read.
- Keeping in mind that we wish to care for all kinds of people in
- the Linux world we might have to make a reading plan. Again,
- an example follows from the Multi Disk HOWTO.</emphasis>
- </para>
-
- <para>
- Although not the biggest HOWTO it is nevertheless rather big
- already and I have been requested to make a reading plan to make
- it possible to cut down on the volume.
- </para>
-
- <para>
- <variablelist>
-
- <varlistentry>
- <term>Expert</term>
- <listitem>
- <para>
- (aka the elite). If you are familiar with Linux as well as
- disk drive technologies you will find most of what you need in
- the appendices. Additionally you are recommended to read the
- FAQ and the <XRef LinkEnd="bits-n-pieces">chapter.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Experienced</term>
- <listitem>
- <para>
- (aka Competent). If you are familiar with computers in
- general you can go straight to the chapters on
- <XRef LinkEnd="technologies"> and continue from there on.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Newbie</term>
- <listitem>
- <para>
- (mostly harmless). You just have to read the whole thing.
- Sorry. In addition you are also recommended to read all the
- other disk related HOWTOs.
- </para>
- </listitem>
- </varlistentry>
-
- </variablelist>
- </para>
- </sect2>
-
- </sect1>
-
-<!-- Section1: structure: END -->
-
-
-<!-- Section1: technologies -->
-
- <sect1 id="technologies">
- <title>Technologies</title>
-
- <indexterm>
- <primary>(your index root)!technologies</primary>
- </indexterm>
-
- <para>
- <emphasis>Introduction of technology for the newbie with a few
- references to detailed works. Remember that not everyone has
- Internet access so you have to explain in sufficient details so
- even the newbie can get by.</emphasis>
- </para>
-
- </sect1>
-
-<!-- Section1: technologies: END -->
-
-
-<!-- Section1: implement -->
-
- <sect1 id="implement">
- <title>Implementation</title>
-
- <indexterm>
- <primary>(your index root)!implementation</primary>
- </indexterm>
-
- <para>
- <emphasis>Now your readers should have a sufficient knowledge of
- what this is about and now we come to the hands on of implementing
- your clever scheme.</emphasis>
- </para>
-
- </sect1>
-
-<!-- Section1: implement: END -->
-
-
-<!-- Section1: maint -->
-
- <sect1 id="maint">
- <title>Maintenance</title>
-
- <indexterm>
- <primary>(your index root)!maintenance</primary>
- </indexterm>
-
- <para>
- <emphasis>Few systems and designs are maintenance free, here you
- explain how to keep the system running.</emphasis>
- </para>
-
- </sect1>
-
-<!-- Section1: maint: END -->
-
-
-<!-- Section1: adv-issues -->
-
- <sect1 id="adv-issues">
- <title>Advanced Issues</title>
-
- <indexterm>
- <primary>(your index root)!advanced topics</primary>
- </indexterm>
-
- <para>
- <emphasis>You can get most things up and running in a quick and
- dirty fashion, useful for testing and getting used to how things
- work. For more serious use you would need to be a little more
- advanced. This is the place to explain it all, if applicable.</emphasis>
- </para>
-
- </sect1>
-
-<!-- Section1: adv-issues: END -->
-
-
-<!-- Section1: moreinfo -->
-
- <sect1 id="moreinfo">
- <title>Further Information</title>
-
- <indexterm>
- <primary>(your index root)!information resources</primary>
- </indexterm>
-
- <para>
- <emphasis>A HOWTO cannot describe everything, some times the user
- has to venture out on th enet to get more information or just
- updates. Here is the place to tell where and how. Again examples
- from the Multi Disk HOWTO, replace as needed.</emphasis> There is wealth
- of information one should go through when setting up a major system,
- for instance for a news or general Internet service provider. The
- FAQs in the following groups are useful:
- </para>
-
-<!-- Section2: newsgroups -->
-
- <sect2 id="newsgroups">
- <title>News groups</title>
-
- <indexterm>
- <primary>disk!information resources!news groups</primary>
- </indexterm>
-
- <para>Some of the most interesting news groups are:
-
- <itemizedlist>
-
- <listitem>
- <para>
- <ulink url="news:comp.arch.storage">Storage</ulink>.
- </para>
- </listitem>
-
- <listitem>
- <para>
- <ulink url="news:comp.sys.ibm.pc.hardware.storage">PC storage</ulink>.
- </para>
- </listitem>
-
- <listitem>
- <para>
- <ulink url="news:alt.filesystems.afs">AFS</ulink>.
- </para>
- </listitem>
-
- <listitem>
- <para>
- <ulink url="news:comp.periphs.scsi">SCSI</ulink>.
- </para>
- </listitem>
-
- <listitem>
- <para>
- <ulink url="news:comp.os.linux.setup">Linux setup</ulink>.
- </para>
- </listitem>
-
- </itemizedlist>
- </para>
-
- <para>
- Most newsgroups have their own FAQ that are designed to answer most
- of your questions, as the name Frequently Asked Questions indicate.
- Fresh versions should be posted regularly to the relevant newsgroups.
- If you cannot find it in your news spool you could go directly to the
- <ulink url="ftp://rtfm.mit.edu/">FAQ main archive FTP site</ulink>.
- The WWW versions can be browsed at the
- <ulink url="http://www.cis.ohio-state.edu/hypertext/faq/usenet/FAQ-List.html">FAQ
- main archive WWW site</ulink>.
- </para>
-
- <para>
- Some FAQs have their own home site, of particular interest:
-
- <itemizedlist>
-
- <listitem>
- <para>
- <ulink url="http://www.paranoia.com/~filipg/HTML/LINK/F_SCSI.html">SCSI FAQ</ulink>
- and
- </para>
- </listitem>
-
- <listitem>
- <para>
- <ulink url="http://alumni.caltech.edu/~rdv/comp_arch_storage/FAQ-1.html">comp.arch.storage FAQ</ulink>.
- </para>
- </listitem>
-
- </itemizedlist>
- </para>
- </sect2>
-
-<!-- Section2: maillists -->
-
- <sect2 id="maillists">
- <title>Mailing Lists</title>
-
- <indexterm>
- <primary>disk!information resources!mailing lists</primary>
- </indexterm>
-
- <para>
- These are low-noise channels mainly for developers. Think twice
- before asking questions there as noise delays the development.
- Some relevant lists are <email>linux-raid</email>,
- <email>linux-scsi</email> and <email>linux-ext2fs</email>. Many
- of the most useful mailing lists run on the <Literal
- remap="tt">vger.rutgers.edu</Literal> server but this is
- notoriously overloaded, so try to find a mirror. There are some
- lists mirrored at <ulink url="http://www.redhat.com">The Redhat
- Home Page</ulink>. Many lists are also accessible at <ulink
- url="http://www.linuxhq.com/lnxlists">linuxhq</ulink>, and the
- rest of the web site contains useful information as well.
- </para>
-
- <para>
- If you want to find out more about the lists available you can send
- a message with the line <command>lists</command> to the list server
- at <email>majordomo@vger.rutgers.edu</email>.
- If you need help on how to use the mail server just send the line
- <command>help</command> to the same address. Due to the
- popularity of this server it is likely it takes a bit to time before
- you get a reply or even get messages after you send a
- <command>subscribe</command> command.
- </para>
-
- <para>
- There is also a number of other majordomo list servers that can
- be of interest such as the EATA driver list
- (<email>linux-eata@mail.uni-mainz.de</email>)
- and the Intelligent IO list <email>linux-i2o@dpt.com</email>.
- </para>
-
- <para>
- Mailing lists are in a state of flux but you can find links to a
- number of interesting lists from the
- <ulink url="http://www.linuxdoc.org/">Linux Documentation
- Homepage</ulink>.
- </para>
- </sect2>
-
-<!-- Section2: howto -->
-
- <sect2 id="howto">
- <title>HOWTO</title>
-
- <indexterm>
- <primary>disk!information resources!HOWTOs</primary>
- </indexterm>
-
- <para>
- These are intended as the primary starting points to get the
- background information as well as show you how to solve a
- specific problem. Some relevant HOWTOs are
- <Literal remap="tt">Bootdisk</Literal>,
- <Literal remap="tt">Installation</Literal>,
- <Literal remap="tt">SCSI</Literal> and
- <Literal remap="tt">UMSDOS</Literal>. The main site for these is the
- <ulink url="http://www.linuxdoc.org/">LDP archive</ulink>at
- Metalab (formerly known as Sunsite).
- </para>
-
- <para>
- There is a a new HOWTO out that deals with setting up a DPT RAID
- system, check out the
- <ulink url="http://www.ram.org/computing/linux/dpt_raid.html">DPT RAID
- HOWTO homepage</ulink>.
- </para>
- </sect2>
-
-<!-- Section2: local-res -->
-
- <sect2 id="local-res">
- <title>Local Resources</title>
-
- <indexterm>
- <primary>disk!information resources!local</primary>
- </indexterm>
-
- <para>
- In most distributions of Linux there is a document directory
- installed, have a look in the <filename>/usr/doc</filename>
- directory. where most packages store their main documentation and
- README files etc. Also you will here find the HOWTO archive
- (<filename>/usr/doc/HOWTO</filename>) of ready formatted HOWTOs
- and also the mini-HOWTO archive
- (<filename>/usr/doc/HOWTO/mini</filename>) of plain text
- documents.
- </para>
-
- <para>
- Many of the configuration files mentioned earlier can be found in
- the <filename>/etc</filename> directory. In particular you will
- want to work with the <filename>/etc/fstab</filename> file that
- sets up the mounting of partitions and possibly also
- <filename>/etc/raidtab</filename> file that is used for the
- <Literal remap="tt">md</Literal> system to set up RAID.
- </para>
-
- <para>
- The kernel source in <filename>/usr/src/linux</filename> is, of
- course, the ultimate documentation. In other words, <quote>use
- the source, Luke</quote>. It should also be pointed out that the
- kernel comes not only with source code which is even commented
- (well, partially at least) but also an informative
- <filename>/usr/src/linux/Documentation</filename>. If you are
- about to ask any questions about the kernel you should read this
- first, it will save you and many others a lot of time and
- possibly embarrassment.
- </para>