Dell PS6000 Configuration Guide - Page 14

Dell EqualLogic Configuration Guide v11.3

9

2.4

RAID Policies

Each array in an EqualLogic array group is configured with a single RAID policy. Arrays (or group

members) within the same storage pool that have the same RAID policy will cooperatively work to host

volumes by distributing those volumes over multiple arrays. Two things defined the RAID policy:



RAID level



hot-spare configuration

Each array implements a default RAID policy that includes a hot-spare. To configure a RAID policy that

does not include a hot-spare you must manually initialize the array using the Command Line Interface.

2.4.1

RAID 5

RAID 5 (striped disks with distributed parity) will combine N disks in an arrangement where each stripe

consists of N-1 disks that contain data blocks plus 1 disk that contains a parity block. For each stripe,

the parity block will be placed on a different disk ensuring that the parity blocks are not located on a

single disk in the RAID set.

RAID 5 implementations can tolerate a single drive failure without data

loss.

For EqualLogic arrays using a RAID 5 policy, Table 5 shows the drive layouts that are enforced based on

the number of drives in each array and the hot spare configuration.

Disk

Drives

Hot Spare

No Hot Spare

7

6 Data/Parity

1 Hot-spare

RAID Policy for RAID 5

without a hot spare is not

supported

8

7 Data/Parity

1 Hot-spare

14

13 Data/Parity

1 Hot-spare

16

15 Data/Parity

1 Hot-spare

48

(a)

46 Data/Parity

2 Hot-spares

(a)

48 drive arrays implement multiple RAID 5 sets within a chassis

Table 5: RAID 5 Drive Layouts

For EqualLogic arrays using a RAID 5 policy, the total quantity of raw storage available can be

computed based on number of drives and the hot spare configuration.

The Table 6 below shows the

amount of raw storage available using the hot spare drive layouts specified in Table 5 above.

Note:

Configuring a RAID policy that does not include a hot-spare will increase the risk

potential for data loss in the event of multiple drive failure.

Section	Page
1 Introduction	6
1.1 Audience	6
1.2 Document Structure	6
2 PS Series Storage Arrays	7
2.1 Array Models	7
2.2 Feature Comparison	8
2.3 Controllers	9
2.3.1 Controller Types	9
2.3.2 Controller Redundancy	10
2.3.3 Controller Failover	10
2.3.4 Firmware	12
Firmware Upgrade	13
2.4 RAID Policies	14
2.4.1 RAID 5	14
2.4.2 RAID 6	15
2.4.3 RAID 10	16
2.4.4 RAID 50	17
3 Peer Storage Operations	19
3.1 Groups	19
3.2 Pools	19
3.3 Volumes	20
3.3.1 Volume Attributes	21
3.3.2 Volume Features	22
3.3.3 Thin Provisioning	22
3.3.4 Snapshots	23
3.3.5 Cloning	23
3.3.6 Replication	24
Example Replication Topologies	25
Sizing Replica Reserve and Delegated Space	28
3.3.7 Clustering	29
4 SAN Design	30
4.1 Implementation of Standards	30
iSNS Support	30
4.2 General Requirements and Recommendations	30
4.2.1 Quality of Service (QoS)	31
4.3 Ethernet Switches and Infrastructure	32
4.3.1 Connecting SAN Switches in a Layer 2 Network	33
Stacking Switches	33
Non-Stacking Switches	34
Using a LAG to Connect Stacked Switches	34
4.3.2 Sizing Inter-Switch Connections	35
4.3.3 Comparing Inter-Switch Connection Types	36
4.4 Host Configuration Guidelines	37
4.4.1 Recommendations for Host Connectivity in Redundant SANs	37
4.4.2 Multi-Path I/O	38
EqualLogic MPIO Requirements	39
EqualLogic MPIO General Recommendations	39
Configuring Microsoft Windows MPIO	39
Configuring VMware vSphere 4.1 Multipathing Extension Module (MEM)	39
4.5 EqualLogic iSCSI SAN Design	40
4.5.1 Redundant SAN Configuration	40
4.5.2 Partially Redundant SAN Configurations	41
Single Array Controller Configurations	41
Dual Array Controller Configurations	42
4.6 Integrating 1GbE and 10GbE SANs	43
5 M1000e Blade Chassis Integration	45
5.1 Guidelines for Stacking Switches in a Blade Chassis	45
5.2 Single M1000e Enclosure Integration	46
5.3 Multiple M1000e Enclosure Integration	46
Dual I/O Module Stacks	46
Single I/O Module Stack	47
5.4 M1000e Ethernet Pass-Through I/O Module	48
5.5 External Tier Stacking	48
5.6 Stack to Stack Interconnect	48
5.6.1 10GbE Uplink Recommendations	48
5.6.2 1GbE Uplink Recommendations	49
Appendix A Network Ports and Protocols	52
A.1 Required Ports and Protocols	52
A.2 Optional Ports and Protocols	52
Appendix B Recommended Switches	54
B.1 Recommended 1GbE Switches	54
B.2 Recommended 10GbE Switches	55
Appendix C Supported iSCSI Initiators	56
C.1 Hardware iSCSI Initiators (HBAs)	56
C.2 Software iSCSI Initiators	57
C.3 Network Interface Controllers	58
Appendix D PowerConnect 54xx Switch Configuration	59
D.1 Disabling iSCSI Optimization Setting	59
D.2 Enabling the PortFast Option to Configure STP Edge Ports	60
D.3 Configuring Flow Control	60
D.4 Disabling Unicast Storm Control	61
D.5 Configuring Jumbo Frames	62
Appendix E PowerConnect 62xx Switch Configuration	63
E.1 Interface Naming Convention	63
E.2 Enabling the PortFast Option to Configure STP Edge Ports	64
E.3 Configuring Flow Control	64
E.4 Disabling Unicast Storm Control	64
E.5 Configuring Jumbo Frames	65
Appendix F Cisco IOS based Switch Configuration	66
F.1 Enabling the PortFast Option to Configure STP Edge Ports	67
F.2 Configuring Flow Control	67
F.3 Disabling Unicast Storm Control	68
F.4 Configuring Jumbo Frames	68

Dell PS6000 Configuration Guide - Page 14

RAID Policies, 2.4.1 RAID 5, RAID 5 - manual

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