First Virtual Communications 3000 Required Number of Drives and Net Capacity, RAID 3 layout

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Voyager 3000 User Guide

RAID 3

Block Striping with Dedicated Parity - Data is broken into logical blocks, the size of a SCSI disk block, and striped across several drives. One drive is dedicated to parity. In the event of failure, original data is re-generated from the parity information.

Table 1-7 RAID 3 layout

Drive 0

A0

A4

B3

C2

Drive 1

A1

B0

B4

C3

Drive 2

A2

B1

C0

C4

Drive 3

A3

B2

C1

D0

Drive 4

P

P

P

P

RAID 5

Multiple Block Striping with Distributed Parity - Sets a given number of logical blocks as a unit for striping across several drives. For small read/write operations, one drive may be activated for improved small record access speed. In this case we can process multiple I/O requests simultaneously. Parity information is interleaved across the drive array. In the event of failure, original data is regenerated from the parity information.

Table 1-8 RAID 5 layout

Drive 0

A0-A1

B3-B4

D1-D2

E4-F0

Drive 1

A2-A3

C0-C1

D3-D4

p

Drive 2

A4-B0

C2-C3

P

F1-F2

Drive 3

B1-B2

P

E0-E1

F3-F4

Drive 4

P

C4-D0

E2-E3

G0-G1

Required Number of Drives and Net Capacity

The following table gives a summary of the minimum number of drives required and the capacity available for the different types of RAID operation:

Table 1-9 Minimum drives necessary for a RAID set

OPERATION	MIN. DRIVES	CAPACITY
	REQUIRED	AVAILABLE
RAID 0	2	T
RAID 1	2	T / 2
RAID 0 + 1	4	T / 2
RAID 3	3	T x (n - 1) / n
RAID 5	3	T x (n - 1) / n

T = Sum of the capacity of all connected drives n = Number of connected drives

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Contents Voyager Revision A41 November-1997Contents EMU Features Figures 31 Mapping Logical Volume 0 Partition 1 to Channel 2 LUN Tables Scope Disclaimer Warranty FAXPage Voyager 3000 Tower configurations Model Number Description Voyager 3000 Rackmountable configurationsVoyager 3000 Family Model Number DescriptionFWD VRA-3001T-XX-YHost Connection Codes Internal bus configuration of VRA-3001T-XX-Y VRA-3002T-XX-YVRA-3002T-XX-Y Scsi target interconnects VRA-3001R-FW-Y example configuration VRA-3001R-XX-YVRA-3002R-FW-Y example configuration VRA-3002R-XX-YSystem Features Device CarrierCooling RAID ControllerPower Supplies Scsi ConnectorsRAID Basics RAID 1 / 0+1Required Number of Drives and Net Capacity RAID 3 layoutRAID 5 layout Minimum drives necessary for a RAID setUnpacking and Initial Setup Ambient TemperatureAir Flow Mechanical LoadingGrounding Electrical ConsiderationsCircuit Overloading Setting the target Scsi Ids on a VRA-3001 system Setting the host Scsi IdsSetting the target Scsi Ids Rear view of single tower showing host connections Setting the target Scsi Ids on a VRA-3002 system Setting the Target Bus Scsi IDsLocation of DPS1 on VRA-3002 second backplane Scsi ID Switch DPS1 Cabling and Termination Issues OffLength in Metres Transfer Speed ComponentsDevices Power Option Board SCA attachmentController Description Part Number11 RAID Controller 13 Installing SIMMs Advanced Cooling ModulesDrive Removal Component Insertion and removalDrive Insertion PSU Insertion and Removal Controller Insertion and RemovalIntroduction Environmental Monitoring Unit ConfigurationsEMU Features Dual shelf configuration System ConfigurationsSingle Shelf configuration Setting up the EMU Location of EMU within the shelfEMU Switch Settings ID settings for the EMUPower Sequencing Signals Available EMU informationSW5 SW6 Read Only Memory locations within the EMUInterpreting the EMU LED feedback Interpreting the EMU LED FeedbackDevices/events monitored by the EMU Connecting the EMU Connecting the EMUs togetherThis page is intentionally left blank Controller Configuration Controller DescriptionAccessing the Voyager 3000 Menus Connecting a MonitorRS232 Terminal Settings Emulating a MonitorWindows Program Manager Setting Windows Terminal Emulation Windows Terminal Preferences Screen Creating a logical volume Windows Terminal Communication Settings10 Initial Screen 12 Verifying Drive Configuration 14 Creating a logical drive 16 Selecting drives for inclusion in a RAID set Creating a Second Logical Volume 19 Progress of RAID set creationAdding a Global Spare 22 Viewing all Logical DrivesPartitioning a Logical Volume 24 Allocating Capacities to partitionsMapping Host LUNs 27 Mapping Host LUNs29 Selecting a Volume for LUN mapping De-assigning LUN Mapping Scan New Scsi DrivesView and Edit logical drives View and Edit Scsi DrivesView and Edit Scsi Channels Scsi ID37 View and edit Scsi target View and Edit Configuration Parameters 38 View and edit configuration parametersDown Loading New Firmware View and Edit Peripheral DevicesSystem Functions Quick Installation View System InformationRAID3 RAID5 Creating a New Logical DriveRAID0 NEW DRV Microp Viewing Disks Assigned to a Logical DriveDRV=5 Assigning a Spare Drive Mapping a Logical Drive to a Host Channel and LUNSetting the Scsi Channels Deleting a Logical DriveCHL SXF=10MChannel Terminator Setting CHL=0Scsi Reset at Power-Up Setting Sequential Drive Spin-Up SettingData Cache Setting Viewing Connected DrivesIssuing a Reset Adding New Drives into Current ListSerial Number Download FirmwareVoyager 3000 User Guide Scsi connectors Operating TemperatureWeight RAID levelPower consumption