Cylinder/Head/Size Hell Is Not Over 

            pixel@mandrakesoft.com 
         $Date$


Nowadays, you can boot Linux without ever relying on CHS
(Cylinder/Head/Size):

- CHS information on partition table is obsolete and not used anymore.
It was causing the 1024th cylinder limitation:
  - disallowing partitions above 8GiG. Problem overcome using 28bits Linear
  Block Addressing (LBA) in partition table.
  - disallowing to boot on partition above 8GiG (due to int13 limitation used
  in bootloaders). Problem overcome using int13 extensions (EDD)

Logical CHS (Cylinder/Head/Size) and physical CHS are not related anymore.
Especially the size of a hard drive is not a multiple of the number of
Cylinders.


The problem is that many tools still rely somewhat heavily on CHS information.
- most tools adjust partitions on cylinder boundary
- some tools compute the size of the disk based on CHS (eg: fdisk)


Resulting problems in various tools:

- last partition not cylinder boundary adjusted, and overrun CHS computed size
  - fdisk
    > Total allocated sectors %d greater than the maximum %d
  - cfdisk (need confirmation)
    > FATAL ERROR: Bad primary partition %d: Partition ends after end-of-disk
    or
    > FATAL ERROR: Bad logical partition %d: Partition ends after end-of-disk
  - Partition Magic (version?)
    > Error #109: Partition ends after end of disk
  - Windows <= 98se, Windows Me
    (doesn't like it, what error message?)

  Tools handling it correctly:
  - parted and so diskdruid in RedHat >= 7.2 (or is it 7.x?)
  - diskdrake >= Mandrake 8.2
  - Windows XP (need confirmation)

  Tools using the full size of the disk, and so causing pbs with fdisk/cfdisk/...:
  - diskdrake == Mandrake 8.2

- disagreement between CHS and linear address
  - parted
    > "Warning: Unable to align partition properly.  This probably means that
    > another partitioning tool generated an
    > incorrect partition table, because it didn't have the correct BIOS
    > geometry.  It is safe to ignore,but
    > ignoring may cause (fixable) problems with some boot loaders.
    > Ignore Cancel ? C
  - lilo
    > Warning: Kernel & BIOS return differing head/sector geometries for device 0x80
    >     Kernel: 38792 cylinders, 16 heads, 63 sectors
    >       BIOS: 1023 cylinders, 255 heads, 63 sectors
    > Device 0x2100: Inconsistent partition table, 2nd entry
    >   CHS address in PT:  48:0:1  -->  LBA (771120)
    >   LBA address in PT:  48384  -->  CHS (3:3:1)
    > The partition table is *NOT* being adjusted.


ame='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/software/forks/initscripts/commit/?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>root</a>/<a href='/software/forks/initscripts/commit/sysconfig?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>sysconfig</a>/<a href='/software/forks/initscripts/commit/sysconfig/network-scripts?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>network-scripts</a>/<a href='/software/forks/initscripts/commit/sysconfig/network-scripts/ifdown-ipsec?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>ifdown-ipsec</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='9.72'/><input type='hidden' name='id' value='6b78527ef407b08b4e2c26f0709375b366e66283'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Bill Nottingham &lt;notting@redhat.com&gt;</td><td class='right'>2003-07-02 22:37:43 +0000</td></tr>
<tr><th>committer</th><td>Bill Nottingham &lt;notting@redhat.com&gt;</td><td class='right'>2003-07-02 22:37:43 +0000</td></tr>
<tr><th>commit</th><td colspan='2' class='sha1'><a href='/software/forks/initscripts/commit/sysconfig/network-scripts/ifdown-ipsec?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>6b78527ef407b08b4e2c26f0709375b366e66283</a> (<a href='/software/forks/initscripts/patch/sysconfig/network-scripts/ifdown-ipsec?id=6b78527ef407b08b4e2c26f0709375b366e66283'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='sha1'><a href='/software/forks/initscripts/tree/?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>5db9039928a64e1fd43afdc49ddec36ad2f827c0</a> /<a href='/software/forks/initscripts/tree/sysconfig/network-scripts/ifdown-ipsec?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>sysconfig/network-scripts/ifdown-ipsec</a></td></tr>
<tr><th>parent</th><td colspan='2' class='sha1'><a href='/software/forks/initscripts/commit/sysconfig/network-scripts/ifdown-ipsec?h=9.72&amp;id=927f8ea11a053120ff7395de0ecf2648dadc8028'>927f8ea11a053120ff7395de0ecf2648dadc8028</a> (<a href='/software/forks/initscripts/diff/sysconfig/network-scripts/ifdown-ipsec?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283&amp;id2=927f8ea11a053120ff7395de0ecf2648dadc8028'>diff</a>)</td></tr><tr><th>download</th><td colspan='2' class='sha1'><a href='/software/forks/initscripts/snapshot/initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.tar'>initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.tar</a><br/><a href='/software/forks/initscripts/snapshot/initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.tar.gz'>initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.tar.gz</a><br/><a href='/software/forks/initscripts/snapshot/initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.tar.bz2'>initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.tar.bz2</a><br/><a href='/software/forks/initscripts/snapshot/initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.tar.xz'>initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.tar.xz</a><br/><a href='/software/forks/initscripts/snapshot/initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.zip'>initscripts-6b78527ef407b08b4e2c26f0709375b366e66283.zip</a><br/></td></tr></table>
<div class='commit-subject'>add ifdown-ipsec</div><div class='commit-msg'></div><div class='diffstat-header'><a href='/software/forks/initscripts/diff/?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>Diffstat</a> (limited to 'sysconfig/network-scripts/ifdown-ipsec')</div><table summary='diffstat' class='diffstat'><tr><td class='mode'>-rwxr-xr-x</td><td class='add'><a href='/software/forks/initscripts/diff/sysconfig/network-scripts/ifdown-ipsec?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>sysconfig/network-scripts/ifdown-ipsec</a></td><td class='right'>29</td><td class='graph'><table summary='file diffstat' width='29%'><tr><td class='add' style='width: 100.0%;'/><td class='rem' style='width: 0.0%;'/><td class='none' style='width: 0.0%;'/></tr></table></td></tr>
</table><div class='diffstat-summary'>1 files changed, 29 insertions, 0 deletions</div><table summary='diff' class='diff'><tr><td><div class='head'>diff --git a/sysconfig/network-scripts/ifdown-ipsec b/sysconfig/network-scripts/ifdown-ipsec<br/>new file mode 100755<br/>index 00000000..d5f8ec50<br/>--- /dev/null<br/>+++ b/<a href='/software/forks/initscripts/tree/sysconfig/network-scripts/ifdown-ipsec?h=9.72&amp;id=6b78527ef407b08b4e2c26f0709375b366e66283'>sysconfig/network-scripts/ifdown-ipsec</a></div><div class='hunk'>@@ -0,0 +1,29 @@</div><div class='add'>+#!/bin/bash</div><div class='add'>+PATH=/sbin:/usr/sbin/:/bin:/usr/bin</div><div class='add'>+</div><div class='add'>+cd /etc/sysconfig/network-scripts</div><div class='add'>+. network-functions</div><div class='add'>+</div><div class='add'>+CONFIG=$1</div><div class='add'>+[ -f "${CONFIG}" ] || CONFIG=ifcfg-${1}</div><div class='add'>+source_config</div><div class='add'>+</div><div class='add'>+if [ -z "$SRC" ]; then</div><div class='add'>+    SRC=`ip -o route get to $DST | sed "s|.*src \([^ ]*\).*|\1|"`</div><div class='add'>+fi</div><div class='add'>+</div><div class='add'>+if [ "$KEYING" = "manual" ]; then</div><div class='add'>+    setkey -c &lt;&lt; EOF</div><div class='add'>+delete $SRC $DST ah $SPI_AH_OUT;</div><div class='add'>+delete $DST $SRC ah $SPI_AH_IN;</div><div class='add'>+delete $SRC $DST esp $SPI_ESP_OUT;</div><div class='add'>+delete $DST $SRC esp $SPI_ESP_IN;</div><div class='add'>+EOF</div><div class='add'>+fi</div><div class='add'>+</div><div class='add'>+setkey -c &lt;&lt; EOF</div><div class='add'>+spddelete $SRC $DST any -P out;</div><div class='add'>+spddelete $DST $SRC any -P in;</div><div class='add'>+EOF</div><div class='add'>+</div><div class='add'>+/etc/sysconfig/network-scripts/ifdown-post $CONFIG</div></td></tr></table></div> <!-- class=content -->
<div class='footer'>generated by <a href='https://git.zx2c4.com/cgit/about/'>cgit v1.2.1</a> (<a href='https://git-scm.com/'>git 2.21.0</a>) at 2026-05-26 03:01:16 +0000</div>
</div> <!-- id=cgit -->
</body>
</html>