LSI SAS2 manual Integrated Striping Description, Integrated Striping Example

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Chapter 4: Overview of Integrated Striping Integrated Striping Description

SAS2 Integrated RAID Solution User Guide

4.3Integrated Striping Description

On Integrated Striping volumes, the firmware writes data across multiple disks instead of onto one disk. It does this by partitioning each disk’s storage space into 64-KB stripes. The firmware interleaves the stripes round-robin so that the combined storage space consists alternately of stripes from each disk.

The following figure shows an example of integrated striping: the firmware writes segment 1 to disk 1, segment 2 to disk 2, segment 3 to disk 3, and so on. When the firmware reaches the end of the disk list, it continues writing data at the next available segment of disk 1.

LSI SAS2

Controller

SAS

Disk 1

Disk 2

Disk 3

Disk 4

Segment 1

Segment 2

Segment 3

Segment 4

Segment 5

Segment 6

Segment 7

Segment 8

Segment 9

Segment 10

Segment 11

Segment 12

3_00010-00

Figure 8: Integrated Striping Example

The following figure shows a logical view and a physical view of an Integrated Striping volume with three disks.

Logical View

 

Physical View

 

Stripe 1

Stripe 1

Stripe 2

Stripe 3

Stripe 2

Stripe 4

Stripe 5

Stripe 6

Stripe 3

+

Stripe 8

+

Stripe 7

Stripe 9

Stripe N

Stripe N-2

Stripe N-1

Stripe N

 

 

 

3_00011-00

Figure 9: Integrated Striping – Logical and Physical Views

Speed is the primary advantage of the Integrated Striping solution because it transfers data to or from multiple disks simultaneously. However, there is no data redundancy. Back the data up on other media to avoid losing unsaved data if one disk fails.

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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 Overview of Integrated RAID Mirrored Volumes IntroductionTypes of mirrored arrays 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 Boot disk or as a data disk Volumes can consist of two-to-ten disksOverview of Integrated Striping 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 Using the SAS2 Integrated RAID Configuration Utility Hardware and SoftwareRequirements 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