287 lines
6.0 KiB
HTML
287 lines
6.0 KiB
HTML
<HTML
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><HEAD
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><TITLE
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>Structure</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.57"><LINK
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REL="HOME"
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TITLE="HOWTO-template for Big HOWTOs"
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HREF="index.html"><LINK
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TITLE="Samples"
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HREF="samples.html"><LINK
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REL="NEXT"
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TITLE="Technologies"
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HREF="technologies.html"></HEAD
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CLASS="SECT1"
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BGCOLOR="#FFFFFF"
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><DIV
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COLSPAN="3"
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>HOWTO-template for Big HOWTOs</TH
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></TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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>Prev</A
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WIDTH="10%"
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ALIGN="right"
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><A
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HREF="technologies.html"
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>Next</A
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></TD
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="SECT1"
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><H1
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CLASS="SECT1"
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><A
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NAME="STRUCTURE"
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>3. Structure</A
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></H1
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><P
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> <I
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CLASS="EMPHASIS"
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>A quick overview on how all parts fit together in the overall
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structure. An example from the Multi Disk HOWTO is used.</I
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>
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</P
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><P
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> As this type of document is supposed to be as much for learning as
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a technical reference document I have rearranged the structure to
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this end. For the designer of a system it is more useful to have
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the information presented in terms of the goals of this exercise
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than from the point of view of the logical layer structure of the
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devices themselves. Nevertheless this document would not be
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complete without such a layer structure the computer field is so
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full of, so I will include it here as an introduction to how it
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works.
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</P
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><DIV
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CLASS="SECT2"
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><H2
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CLASS="SECT2"
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><A
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NAME="LOGICAL-STRUCT"
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>3.1. Logical structure</A
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></H2
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><P
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> This is based on how each layer access each other, traditionally
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with the application on top and the physical layer on the bottom.
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It is quite useful to show the interrelationship between each of
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the layers used in controlling drives.
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="SCREEN"
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> ___________________________________________________________
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|__ File structure ( /usr /tmp etc) __|
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|__ File system (ext2fs, vfat etc) __|
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|__ Volume management (AFS) __|
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|__ RAID, concatenation (md) __|
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|__ Device driver (SCSI, IDE etc) __|
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|__ Controller (chip, card) __|
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|__ Connection (cable, network) __|
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|__ Drive (magnetic, optical etc) __|
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-----------------------------------------------------------
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</PRE
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></TD
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></TR
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></TABLE
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>
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</P
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><P
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> In the above diagram both volume management and RAID and
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concatenation are optional layers. The 3 lower layers are in
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hardware. All parts are discussed at length later on in this
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document.
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</P
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></DIV
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><DIV
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CLASS="SECT2"
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><H2
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CLASS="SECT2"
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><A
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NAME="DOC-STRUCT"
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>3.2. Document structure</A
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></H2
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><P
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> Most users start out with a given set of hardware and some plans
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on what they wish to achieve and how big the system should be.
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This is the point of view I will adopt in this document in
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presenting the material, starting out with hardware, continuing
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with design constraints before detailing the design strategy that
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I have found to work well. I have used this both for my own
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personal computer at home, a multi purpose server at work and
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found it worked quite well. In addition my Japanese co-worker in
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this project have applied the same strategy on a server in an
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academic setting with similar success.
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</P
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><P
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> Finally at the end I have detailed some configuration tables for
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use in your own design. If you have any comments regarding this
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or notes from your own design work I would like to hear from you
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so this document can be upgraded.
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</P
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></DIV
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><DIV
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CLASS="SECT2"
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><H2
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CLASS="SECT2"
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><A
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NAME="READING-PLAN"
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>3.3. Reading plan</A
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></H2
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><P
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> <I
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CLASS="EMPHASIS"
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>As you go beyond 50 pages or so there will be a lot of
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text that experts and even the experienced do not need to read.
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Keeping in mind that we wish to care for all kinds of people in
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the Linux world we might have to make a reading plan. Again,
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an example follows from the Multi Disk HOWTO.</I
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>
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</P
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><P
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> Although not the biggest HOWTO it is nevertheless rather big
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already and I have been requested to make a reading plan to make
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it possible to cut down on the volume.
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</P
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><P
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> <P
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></P
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><DIV
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CLASS="VARIABLELIST"
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><DL
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><DT
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>Expert</DT
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><DD
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><P
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> (aka the elite). If you are familiar with Linux as well as
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disk drive technologies you will find most of what you need in
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the appendices. Additionally you are recommended to read the
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FAQ and the <A
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HREF="bits-n-pieces.html"
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>Section 12</A
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>chapter.
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</P
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></DD
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><DT
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>Experienced</DT
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><DD
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><P
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> (aka Competent). If you are familiar with computers in
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general you can go straight to the chapters on
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<A
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HREF="technologies.html"
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>Section 4</A
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> and continue from there on.
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</P
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></DD
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><DT
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>Newbie</DT
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><DD
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><P
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> (mostly harmless). You just have to read the whole thing.
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Sorry. In addition you are also recommended to read all the
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other disk related HOWTOs.
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</P
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></DD
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></DL
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></DIV
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>
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</P
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></DIV
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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><TR
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WIDTH="33%"
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><A
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HREF="samples.html"
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>Prev</A
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></TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
|
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><A
|
|
HREF="technologies.html"
|
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>Next</A
|
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></TD
|
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></TR
|
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><TR
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><TD
|
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WIDTH="33%"
|
|
ALIGN="left"
|
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VALIGN="top"
|
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>Samples</TD
|
|
><TD
|
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WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
> </TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
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>Technologies</TD
|
|
></TR
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></TABLE
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></BODY
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> |