Overview

This chapter provides some guidelines for performing an upgrade installation and for preserving local modifications before upgrading from a previous version of Solaris software.

Can You Use Upgrade?

Upgrade and initial are options in the Solaris installation program that determine how Solaris software is copied to disk:

• Upgrade - merges the new version of Solaris software with existing files on the system's disk. It saves as many local modifications as possible.
• Initial - overwrites the system's disk with the new version of Solaris software.

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Note - The upgrade option is not available for 4.1.x systems. Because you must use the initial installation option, backing up your data is critical. See the Solaris 1.x to Solaris 2.x Transition Guide for information.

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To determine if your system supports the upgrade, see the following table.

Upgrade Option Is Available If at least one disk attached to the system has a Solaris 2.1 or later root file system. 1) To determine if the system has a root file system, type the following command: df -a Look for a line of output similar to the following: Filesystem kbytes used avail capacity Mounted on /dev/dsk/c0t1d0s048295 15665 27810 36% / 2) To determine if the system is running Solaris 2.1 or later, type the following commands: cd /var/sadm/softinfo more INST_RELEASE

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Note - The upgrade option may require deleting software packages if the disk is full; this requires knowledge of packages and dependencies.

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Backing Up Your System

Always back up an existing system before installing a new version of Solaris software, even if you choose the upgrade option. The safest backup to perform is a level 0 dump of all the file systems connected to the system being upgraded. If you do not have an established backup procedure, see File System Administration.

Preserving Local Modifications

During an upgrade, the Solaris installation program attempts to preserve local modifications to the system whenever possible; however, sometimes local modifications can make an upgrade fail or perform differently than you would expect. Table 6-1 indicates tasks you should perform before upgrading to make your upgrade a success.

Table 6-1

What to Do Before Upgrading	How to	Why
Preserve symbolic links	Replace symbolic links that use absolute paths with symbolic links that use relative paths.	During an upgrade, the installation program cannot reference symbolic links that use absolute paths, because the Solaris installation program mounts the root (/) file
	For example, if /usr/openwin is a symbolic link to /export/openwin, change the symbolic link to ../export/openwin.	system at /a. For example, a symbolic link to /export/openwin would fail, because during an upgrade, /export/openwin is really /a/export/openwin. When the Solaris installation program cannot reference a symbolic link, it will overwrite the symbolic link and install the software (the installation program doesn't think the software exists). As a result, duplicate software will be installed on the system and the upgrade may fail because of insufficient disk space.
Preserve symbolic links to automounted file systems	Remove packages (by using Software Manager or the pkgrm command) that will create files or directories currently automounted.	The automounter is not active during an upgrade, so the Solaris installation program installs any package's files or directories that are symbolic links to automounted file systems. If a symbolic link is overwritten, the upgrade may fail because of insufficient disk space. (If you cannot remove a package, you can replace the symbolic link after the upgrade is completed.) Note: The /var/mail and /var/news directories, which usually reside on an automounted file system, are not affected by an upgrade.

Table 6-1

What to Do Before Upgrading	How to	Why
Prevent unneeded file systems from being mounted	Comment out file systems in the /etc/vfstab file that you do not want mounted during an upgrade.	During an upgrade, the Solaris installation program attempts to mount all the file systems listed in the /etc/vfstab file on the root file system being upgraded. If the Solaris installation program cannot mount a file system, it reports the failure and exits.