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Update Question 3.25:

Browse source 
- 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>
<question id="ffs-limits">
<para>What are the limits for ffs filesystems?</para>
<para>What are the limits for FFS file systems?</para>
</question>
<answer>
<para>For ffs filesystems, the maximum theoretical limit is 8
terabytes (2G blocks), or 16TB for the default block size of
8K. In practice, there is a soft limit of 1 terabyte, but with
modifications filesystems with 4 terabytes are possible (and
<para>For FFS file systems, the maximum theoretical limit is 8&nbsp;TB
(2&nbsp;G blocks), or 16&nbsp;TB for the default block size of
8&nbsp;KB. In practice, there is a soft limit of 1&nbsp;TB, but with
modifications file systems with 4&nbsp;TB are possible (and
exist).</para>
<para>The maximum size of a single ffs file is approximately 1G
blocks, or 4TB with a block size of 4K.</para>
<para>The maximum size of a single FFS file is approximately 1&nbsp;G
blocks, or 4&nbsp;TB with a block size of 4&nbsp;KB.</para>
<table>
<title>Maximum file sizes</title>
@ -1952,71 +1952,73 @@
<tgroup cols="3">
<thead>
<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>
</thead>
<tbody>
<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>
<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>
<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>
<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>
<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>
</tbody>
</tgroup>
</table>
<para>When the fs block size is 4K, triple indirect blocks work
and everything should be limited by the maximum fs block number
<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
that can be represented using triple indirect blocks (approx.
1K^3 + 1K^2 + 1K), but everything is limited by a (wrong) limit
of 1G-1 on fs block numbers. The limit on fs block numbers
should be 2G-1. There are some bugs for fs block numbers near
2G-1, but such block numbers are unreachable when the fs block
size is 4K.</para>
1024<superscript>3</superscript>&nbsp;+&nbsp;1024<superscript>2</superscript>&nbsp;+&nbsp;1024),
but everything is limited by a (wrong) limit
of 1&nbsp;G&nbsp;-&nbsp;1 on FS block numbers. The limit on FS block numbers
should be 2&nbsp;G&nbsp;-&nbsp;1. There are some bugs for FS block numbers near
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
limited by the 2G-1 limit on fs block numbers, but is
actually limited by the 1G-1 limit on fs block numbers.
Using the correct limit of 2G-1 blocks does cause
<para>For block sizes of 8&nbsp;KB and larger, everything should be
limited by the 2&nbsp;G&nbsp;-&nbsp;1 limit on FS block numbers, but is
actually limited by the 1&nbsp;G&nbsp;-&nbsp;1 limit on FS block numbers.
Using the correct limit of 2&nbsp;G&nbsp;-&nbsp;1 blocks does cause
problems.</para>
</answer>