System Reconfiguration

This section describes how to reconfigure your system after you have configured or unconfigured a system board.

When to Reconfigure

You might need to reconfigure the system under several conditions, including:

• Board addition: When adding a board, you must execute the reconfiguration sequence to configure the I/O devices associated with the board.

• Board removal: If you remove a board that is not to be replaced, you may (but do not have to) execute the reconfiguration sequence to clean up the /dev links for disk devices.

• Board replacement: If you remove a board and then insert it into a different slot, or replace a board with another board that has different I/O devices, you must execute the reconfiguration sequence to configure the I/O devices associated with the board. However, if you replace a board with another board that hosts the same set of I/O devices, inserting the replacement into the same slot, you do not need to execute the reconfiguration sequence. But be sure to insert a replacement into the same slot that was vacated to retain the original /dev link names.

I/O Device Reconfiguration

The DR reconfiguration sequence is the same as the Solaris reconfiguration boot sequence (boot -r):

drvconfig; devlinks; disks; ports; tapes;

When the reconfiguration sequence is executed after a board is configured, device path names not previously seen by the system are entered into the /etc/path_to_inst file. The same path names are also added to the /devices hierarchy and links to them are created in the /dev directory.

Disk Controller Renumbering during a Reconfiguration

The disk controller number is part of the /dev link name used to access the disk. If that number changes during the reconfiguration sequence, the /dev link name also changes. This change may affect file system tables and software, such as Solstice(TM) DiskSuite(TM), which uses the /dev link names. Update /etc/vfstab files and execute other administrative actions necessary due to the changes in the /dev link names.

When the reconfiguration sequence is executed after a board is unconfigured or disconnected, the /dev links for all the disk partitions on that board are deleted. The remaining boards retain their current numbering. Disk controllers on a newly inserted board are assigned the next available lowest number by disks(1M).

The disks(1m) utility creates symbolic links in the /dev/dsk and /dev/rdsk directories pointing to the actual special disk device files under the /devices directory tree. These entries take the form /dev/dsk/cXtXdXsX where:

• cX is the disk controller number

• tX corresponds to the disk target number, in most cases

• dX refers to the logical unit number

• sX is the partition number

Removing boards that contain one or more disk controllers prompts the disks(1m) utility to examine entries in /dev/dsk and /dev/rdsk. These entries list the disks attached to the removed controller(s). The disks(1m) utility discovers references to disconnected devices have been removed from /dev/dsk and /dev/rdsk. This removal action makes the logical controller numbers available for re-use. This re-use of controller numbers can lead to confusion when unexpected controller numbers are assigned to disk controllers that are added to the system.