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Update Question 3.25:

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- Capitalize FFS and Table Heads
- Unificate and clarify units
- Add non-breakable spaces for better rendering
- Introduce <superscript> :)
- Exchange items in the first row

Reviewed by:	trhodes, danger, remko
Approved by:	gabor (mentor)
This commit is contained in:
Gabor Pali 2008-06-14 09:48:31 +00:00
parent 97322d202e
commit 3d03cf04ec
Notes: svn2git 2020-12-08 03:00:23 +00:00 
svn path=/head/; revision=32221
1 changed files with 38 additions and 36 deletions
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74
en_US.ISO8859-1/books/faq/book.sgml
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@ -1933,18 +1933,18 @@
<qandaentry> <qandaentry>
<question id="ffs-limits"> <question id="ffs-limits">
<para>What are the limits for ffs filesystems?</para> <para>What are the limits for FFS file systems?</para>
</question> </question>
<answer> <answer>
<para>For ffs filesystems, the maximum theoretical limit is 8 <para>For FFS file systems, the maximum theoretical limit is 8&nbsp;TB
terabytes (2G blocks), or 16TB for the default block size of (2&nbsp;G blocks), or 16&nbsp;TB for the default block size of
8K. In practice, there is a soft limit of 1 terabyte, but with 8&nbsp;KB. In practice, there is a soft limit of 1&nbsp;TB, but with
modifications filesystems with 4 terabytes are possible (and modifications file systems with 4&nbsp;TB are possible (and
exist).</para> exist).</para>
<para>The maximum size of a single ffs file is approximately 1G <para>The maximum size of a single FFS file is approximately 1&nbsp;G
blocks, or 4TB with a block size of 4K.</para> blocks, or 4&nbsp;TB with a block size of 4&nbsp;KB.</para>
<table> <table>
<title>Maximum file sizes</title> <title>Maximum file sizes</title>
@ -1952,71 +1952,73 @@
<tgroup cols="3"> <tgroup cols="3">
<thead> <thead>
<row> <row>
<entry>fs block size</entry> <entry>FS Block Size</entry>
<entry>works</entry> <entry>Works</entry>
<entry>should work</entry> <entry>Should Work</entry>
</row> </row>
</thead> </thead>
<tbody> <tbody>
<row> <row>
<entry>4K</entry> <entry>4&nbsp;KB</entry>
<entry>4T-1</entry> <entry>&gt;&nbsp;4&nbsp;GB</entry>
<entry>4&nbsp;TB&nbsp;-&nbsp;1</entry>
<entry>&gt;4T</entry>
</row> </row>
<row> <row>
<entry>8K</entry> <entry>8&nbsp;KB</entry>
<entry>&gt;32G</entry> <entry>&gt;&nbsp;32&nbsp;GB</entry>
<entry>32T-1</entry> <entry>32&nbsp;TB&nbsp;-&nbsp;1</entry>
</row> </row>
<row> <row>
<entry>16K</entry> <entry>16&nbsp;KB</entry>
<entry>&gt;128G</entry> <entry>&gt;&nbsp;128&nbsp;GB</entry>
<entry>32T-1</entry> <entry>32&nbsp;TB&nbsp;-&nbsp;1</entry>
</row> </row>
<row> <row>
<entry>32K</entry> <entry>32&nbsp;KB</entry>
<entry>&gt;512G</entry> <entry>&gt;&nbsp;512&nbsp;GB</entry>
<entry>64T-1</entry> <entry>64&nbsp;TB&nbsp;-&nbsp;1</entry>
</row> </row>
<row> <row>
<entry>64K</entry> <entry>64&nbsp;KB</entry>
<entry>&gt;2048G</entry> <entry>&gt;&nbsp;2048&nbsp;GB</entry>
<entry>128T-1</entry> <entry>128&nbsp;TB&nbsp;-&nbsp;1</entry>
</row> </row>
</tbody> </tbody>
</tgroup> </tgroup>
</table> </table>
<para>When the fs block size is 4K, triple indirect blocks work <para>When the FS block size is 4&nbsp;KB, triple indirect blocks work
and everything should be limited by the maximum fs block number and everything should be limited by the maximum FS block number
that can be represented using triple indirect blocks (approx. that can be represented using triple indirect blocks (approx.
1K^3 + 1K^2 + 1K), but everything is limited by a (wrong) limit 1024<superscript>3</superscript>&nbsp;+&nbsp;1024<superscript>2</superscript>&nbsp;+&nbsp;1024),
of 1G-1 on fs block numbers. The limit on fs block numbers but everything is limited by a (wrong) limit
should be 2G-1. There are some bugs for fs block numbers near of 1&nbsp;G&nbsp;-&nbsp;1 on FS block numbers. The limit on FS block numbers
2G-1, but such block numbers are unreachable when the fs block should be 2&nbsp;G&nbsp;-&nbsp;1. There are some bugs for FS block numbers near
size is 4K.</para> 2&nbsp;G&nbsp;-&nbsp;1, but such block numbers are unreachable when the FS block
size is 4&nbsp;KB.</para>
<para>For block sizes of 8K and larger, everything should be <para>For block sizes of 8&nbsp;KB and larger, everything should be
limited by the 2G-1 limit on fs block numbers, but is limited by the 2&nbsp;G&nbsp;-&nbsp;1 limit on FS block numbers, but is
actually limited by the 1G-1 limit on fs block numbers. actually limited by the 1&nbsp;G&nbsp;-&nbsp;1 limit on FS block numbers.
Using the correct limit of 2G-1 blocks does cause Using the correct limit of 2&nbsp;G&nbsp;-&nbsp;1 blocks does cause
problems.</para> problems.</para>
</answer> </answer>