https://wiki.openvz.org/index.php?action=history&feed=atom&title=Sysfs_layoutsSysfs layouts - Revision history2026-06-14T12:49:40ZRevision history for this page on the wikiMediaWiki 1.31.1https://wiki.openvz.org/index.php?title=Sysfs_layouts&diff=8311&oldid=prevKir: added to kernel category2010-03-12T14:03:06Z<p>added to kernel category</p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 14:03, 12 March 2010</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>on old distro, you should probably boot it with the option in question set.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>on old distro, you should probably boot it with the option in question set.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Troubleshooting]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Troubleshooting]]</div></td></tr>
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</table>Kirhttps://wiki.openvz.org/index.php?title=Sysfs_layouts&diff=8310&oldid=prev195.214.232.10: Described the old_sysfs option2010-03-12T13:24:25Z<p>Described the old_sysfs option</p>
<p><b>New page</b></p><div>This page describes what problems can you have with sysfs<br />
<br />
== Intro ==<br />
Sysfs can exist in two layouts. They are selected by the <code>CONFIG_SYSFS_DEPRECATED_V2</code><br />
config option. There are two main differences between them<br />
# block devices are stored in the <code>/sys/block</code> or in the <code>/sys/class/block</code><br />
# some devices live in the <code>/sys/devices</code> or in the <code>/sys/class</code><br />
<br />
Although sysfs puts symlinks between old and new entries where possible, not all userspace can<br />
work with it.<br />
<br />
== Known issues ==<br />
=== Old nash on new layout ===<br />
<code>Nash</code> is a small shell used on initrd/initramdisk-s to boot the system.<br />
<br />
With the new sysfs layout (i.e. the option is question is ''not'' set) the old <code>nash</code><br />
tool (such as the one used in CentOS-5) cannot recognise the block devices. This results in <br />
inability to mount the root filesystem.<br />
<br />
To workaround the issue you should turn the deprecated layout on in .config and rebuild the kernel.<br />
All OpenVZ kernel prior to 2.6.27 (and including one) are build with this layout.<br />
<br />
=== New udev on old layout ===<br />
With the old sysfs layout (i.e. with the option set to <code>y</code>) the udev used in newer<br />
distros (such as FC12) prints a warning about the old layout used.<br />
<br />
Currently this doesn't bring any problems to user, but in future situation may change.<br />
<br />
To workaround the issue you should turn the deprecated layout off in .config and rebuild the kernel.<br />
<br />
== Dynamic selection ==<br />
In 2.6.32 OpenVZ kernel there's a boot option called <code>old_sysfs</code> which turns the<br />
deprecated layout on at boot. This one is off by default, so if you're using the 2.6.32 kernel<br />
on old distro, you should probably boot it with the option in question set.<br />
[[Category:Troubleshooting]]</div>195.214.232.10