LSI SAS2 manual Operation of Mirrored Volumes

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Chapter 2: Overview of Integrated RAID Mirrored Volumes Operation of Mirrored Volumes

SAS2 Integrated RAID Solution User Guide

2.3Operation of Mirrored Volumes

Ability of mirrored volumes to run in optimal mode or in degraded mode if one mirrored disk in an Integrated Mirroring volume fails or if one or more mirrored disks fail in an Integrated Mirroring + Striping volume or Integrated Mirroring Enhanced volume.

Support for hot swapping.

Support for online capacity expansion (OCE) for RAID 1 volumes. OCE allows you to increase the size of a RAID 1 volume by replacing the existing disk drives with higher-capacity disk drives. Data is protected during the expansion process, and the RAID 1 volume remains online.

Presentation of a single, virtual drive to the operating system for each mirrored volume.

Support for both SAS and SATA disks, although you cannot combine the two types of disks in the same volume. However, an LSI SAS2 controller can support one volume with SATA disks and a second volume with SAS disks.

Automatic background initialization after volume creation.

Consistency checking.

Fusion-MPT architecture.

Menu-driven, BIOS-based configuration utility.

Error notification, in which the drivers update an OS-specific event log.

Support for SCSI Enclosure Services (SES) status LED.

Write journaling, which allows automatic synchronization of potentially inconsistent data after unexpected powerdown situations.

Use of metadata to store volume configuration on disks in a mirrored volume.

Automatic background resynchronization while host I/Os continue.

Background media verification, which ensures that data on mirrored volumes is always accessible.

The LSI Integrated RAID solution supports one or two mirrored volumes on each LSI SAS2 controller (or one mirrored volume and one Integrated Striping volume). Typically, one of these volumes is the boot volume. Boot support is available through the firmware of the LSI SAS2 controller that supports the standard Fusion-MPT interface. The runtime mirroring of the boot disk is transparent to the BIOS, the drivers, and the operating system. Host-based status software monitors the state of the mirrored disks and reports any error conditions. The following figure shows an Integrated Mirroring volume in which the second disk is a mirrored copy of the data on the first (primary) disk.

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LSI Corporation Confidential August 2010

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Contents SAS2 Integrated RAID Solution Revision History Table of Contents Table of Contents Introduction to the Integrated RAID Solution FeaturesOverview Enhanced RAID 1EBenefits and Features Types of mirrored arrays Overview of Integrated RAID Mirrored VolumesIntroduction Operation of Mirrored Volumes Typical Integrated Mirroring Implementation Integrated Mirroring Enhanced with Three Disks Mirrored Volume Features SAS2 Integrated RAID Solution User Guide Creating Mirrored Volumes Mirrored VolumeConfiguration Overview Please wait, invoking SAS Configuration UtilitySelect Create RAID 1 Volume Create New Array window appearsSelect Create RAID 1E Volume Expanding an Integrated Mirroring Volume with OCE Manage Array window appears Select New Array Type window appearsArray on this adapter Following figureManage Hot Spares window appears Smart supportHot Spare status changes to Yes Press C to create the hot spare diskOther Configuration Tasks Follow these steps to activate a selected volume Currently inactivePress Enter Select RAID Properties, and then press EnterFollow these steps to select a boot disk SAS2 Bios CU, select an adapter from the Adapter ListHighlight SAS Topology, and press Enter SAS Topology window appearsBoot Device on SAS Topology Window Overview of Integrated Striping Boot disk or as a data diskVolumes can consist of two-to-ten disks Integrated Striping Description Integrated Striping ExampleCreating Integrated Striping Volumes Creating Integrated Striping VolumesSelect Create RAID 0 Volume Viewing Volume Properties Activating an Array Select Delete Array Alternate device Following figure showsSAS2 Integrated RAID Solution User Guide Requirements Using the SAS2 Integrated RAID Configuration UtilityHardware and Software Interface Description Commands EFICommand to get the enclosure and slot numbers of a drive GB of capacity on the disk driveFollowing fields of IOC Page 6 specify the configuration MPI2 specification and is specific for SSD drives only VolumeName a user-specified string to identify the volume Appearing while the command is runningSas2ircu controller# delete noprompt Sas2ircu controller# display filename112 Initiator IDDrive Type Enclosure information Enclosure# Logical IDConfiguration has changed or a drive has failed Failed FLD The volume has failedMissing MIS The volume is missing Initializing Init The volume is initializingSas2ircu controller# hotspare delete EnclosureBay Sas2ircu controller# status Volume status Enabled or Disabled  Physical disk I/Os Quiesced or Not quiescedSas2ircu list NoneSas2ircu controller# constchk volumeId noprompt Sas2ircu controller# activate volumeIdSas2ircu controller# logir action filename noprompt