Starting with patch 119254-42 and 119255-42, the patch installation utilities, patchadd and patchrm, have been modified to change the way that certain patches delivering features are handled. This modification affects the installation of these patches on any Solaris 10 release. These “deferred-activation” patches handle the large scope of change delivered in feature patches better.
A limited number of patches are designated as a deferred-activation patch. Typically a deferred-activation patch is a kernel patch associated with a Solaris 10 release after the Solaris 10 3/05 release, such as the Solaris 10 8/07 release. Patches are designated a deferred-activation patch if the variable SUNW_PATCH_SAFEMODE is set in the pkginfo file. Patches not designated as deferred-activation patches continue to install as before. For example, previously released patches, such as kernel patches 118833-36 (SPARC) and 118855-36 (x86), do not use the deferred-activation patching utilities to install.
Previously, complex patch scripting was required for these kernel patches. The scripting was required to avoid issues during the patch installation process on an active partition because of inconsistencies between the objects the patch delivers and the running system (active partition). Now, deferred-activation patching uses the loopback file system (lofs) to ensure the stability of the running system. When a patch is applied to the running system, the lofs preserves stability during the patching process. These large kernel patches have always required a reboot, but now the required reboot activates the changes made by the lofs. The patch README provides instructions on which patches require a reboot.
If you are running non-global zones or have lofs disabled, consider these points when installing or removing deferred-activation patches:
All non-global zones must be in a halted state for this patch operation. You must halt the non-global zone before applying the patch.
Deferred-activation patching requires the loopback file system (lofs) in order to complete safely. Systems running Sun Cluster 3.1 or Sun Cluster 3.2 are likely to have lofs turned off because of restrictions on HA-NFS functionality when lofs is enabled. Therefore, before a deferred-activation patch is installed, you must re-enable the loopback file system by performing the following steps:
Remove or comment out the following line in the /etc/system file:
Reboot the system.
Install the patch.
After you have completed the patch installation operation, restore or uncomment the same line from the /etc/system file.
Reboot the system to resume normal operations.
Sun recommends Solaris Live Upgrade to manage patching. Solaris Live Upgrade prevents the problems of patching a running system. Solaris Live Upgrade reduces the amount of downtime involved in patching and reduces risk by providing fallback capability if problems occur. See Solaris 10 Installation Guide: Solaris Live Upgrade and Upgrade Planning.