NAME

rm6 - RAID Manager Overview

OVERVIEW

RAID Manager is a software package designed to facilitate disk array management and administration. The primary interface to these functions is through a set of graphical applications. In addition, certain tasks that are important to array management are carried out automatically by "daemon" processes that run from system startup to system shutdown. Also, some functions are available in the form of command line utilities that make it possible to embed customized and/or iterative operations in shell scripts.

COMPONENTS

Graphical User Interface

This release has four graphical applications which can be initiated from icons under the application "launcher". The applications are:

Configuration - This application is primarily for specifying how physical drives in the array are to be utilized in terms of allocation to logical units for data storage or "hot spare" assignment; various logical unit attributes may also be specified as part of LUN creation.

Status - This application permits an administrator to determine if an array has, or has had in the past, any abnormal or unusual status condition associated with it. Three kinds of status information are available under this application: (1) message log viewing, which permits browsing and detailed viewing of accumulated history information pertaining to array exception conditions; (2) "on-demand" health checking, which examines selected arrays for any fault conditions that need to be remedied; and (3) reconstruction status, which permits viewing of reconstruction progress for logical units that have had failed drives replaced.

Recovery Guru - This application assists an administrator in the process of carrying out recovery operations on degraded hardware. The recovery guru "knows" about certain failure modes and attempts to lead the user through the necessary recovery steps, ensuring that the user goes about replacing components in the right manner and taking combinations of multiple failed components into account, if necessary.

Maintenance and Tuning - This application provides control of certain array management tasks that arise from time to time in a RAID configuration, including controller software download, array parity validation, and controller cache tuning.

Command Line Programs

This release has several command Line utilities, each fully described in a separate man page:

lad (list array devices) - This program identifies what array controller and logical units are connected to the system.

nvutil (NVSRAM display/modification utility) - This program permits the viewing and changing of array controller non-volatile RAM settings,allowing for a level of "after-market" customization of controller behavior.

parityck (parity check/repair) - This program checks, and if necessary, repairs the parity information stored on the array. (While correct parity is vital to the operation of the array, the possibility of damage to parity is extremely unlikely).

raidutil (RAID configuration utility) - This program is the command line counterpart to the graphical configuration application. It permits RAID logical unit and hot spare creation and deletion to be controlled from a command line or shell script.

rdacutil (redundant disk array controller management utility) - This program permits certain redundant controller operations such as LUN load balancing and controller failover and restoration to be performed from a command line or shell script.

Daemon Programs and Driver Modules

The following daemon programs and driver modules are supplied with RAID Manager in support of certain automated functions for problem notification and error recovery:

arraymon (array monitor daemon) - The primary function of the array monitor daemon is to watch for the occurrence of exception conditions in the array subsystems and provide administrator notification when they happen.

rdaemon (redundant I/O path error resolution daemon) - The primary function of rdaemon is to receive and react to redundant controller exception events and to participate in the application-transparent recovery of those events through error analysis and, if necessary, controller failover.

rdriver (redundant I/O path routing driver) - The rdriver module works in cooperation with rdaemon in handling the transparent recovery of I/O path failures. Its primary responsibilities include routing I/Os down the proper path and communicating with the rdaemon about errors and their resolution.

Customizable Elements

RAID Manager has two primary means for end users to customize the program to their particular needs, the rmparams file and the rmscript file, each described below:

rmparams (RAID Manager parameter file) - rmparams is an ASCII file that has a number of parameter settings for such things as the array monitor poll interval, what time to perform the daily array parity check, etc. The RAID Manager programs read this file on startup or at select times during their execution and adapt their behavior accordingly. A subset of the parameters in rmparams are changeable under the graphical interface.

rmscript (RAID Manager notification script) - rmscript is a shell program that is called by the array daemon and other programs whenever an important event is reported. The file has certain standard actions, including posting the event to the RAID Manager message log, sending e-mail to the super user, and, in some case, sending an SNMP trap; however, rmscript may be edited as the user sees fit, so long as care is taken to not disturb any of the standard actions that the user wants to retain.

FILES

/etc/raid

"home" directory for the RAID Manager distribution files

/etc/raid/bin/rm6

shell script to launch the RAID Manager graphical interface

/etc/raid/rmparams

the RAID Manager parameter file

/etc/raid/rmscript

the RAID Manager notification shell script

SEE ALSO

arraymon(1M), lad(1M), nvutil(1M), parityck(1M), raidutil(1M), rdac(7), rdacutil(1M), rdaemon(1M), rdriver(4), rmevent(4), rmparams(4), rmscript(1M)