1. Fujitsu Training Documentation RAID Groups and Volumes
RAID Groups and Volumes ETERNUS DX S3 / S4
ETERNUS DX 60 S4, DX100 S4, DX200 S4 DX 60 S3, DX100 S3, DX200 S3 DX500 S3, DX600 S3 DX8700 S3, DX8900 S3 AF250, AF650
RAID Groups and Volumes
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

2. Fujitsu Training Documentation
RAID Groups and Volumes ETERNUS DX S3 / S4
Contents
RAID Functionality
Dynamic LUN Configuration
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

3. Fujitsu Training Documentation
RAID Groups and Volumes ETERNUS DX S3 / S4
RAID Functionality
Supported RAID Levels
Comparison RAID 5+0 and RAID 5
Improved Reliability and Performance with RAID 5+0
Further Improved Reliability with RAID 5+0
Comparison Between RAID 5, 5+0 and 6
Introduction into RAID 6FR
Stripe Depth
RAID Groups and Volumes ETERNUS DX S3 / S4
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Copyright Fujitsu, Release June 2017

4. Fujitsu Training Documentation
Supported RAID Levels
RAID Groups and Volumes ETERNUS DX S3 / S4
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

5. Comparison RAID 5+0 and RAID 5
Fujitsu Training Documentation
Comparison RAID 5+0 and RAID 5
RAID Groups and Volumes ETERNUS DX S3 / S4
RAID 5+0 provides high performance and large capacity by striping the data and parity blocks over two RAID 5 configurations
This increases the data transfer rate in comparison to a standard RAID 5 configuration
RAID 5
RAID 5+0
Because RAID 5+0 consist in practice of two RAID 5 sets it enables a RAID Group with double the capacity of RAID 5
RAID 5 can be set up from 2+1 up to maximum 15+1 disk configuration
RAID 5+0 can be set up from 2 x (2+1 up to maximum 15+1) P3
D3-1
D2-1
D1-1
D2-2
D1-2
D3-2
RAID 5 (3D+1P)
D3-3
D2-3 P1 P2
D1-3
4 drives
"D" = data area
"P" = parity area
RAID 5+0 (3D+1P) x 2
D3-1
D2-1
D1-1 P3
D2-2
D1-2
D3-2 P2
D1-3
D3-3
D2-3 P1
D3-4
D2-4
D1-4
P3”
D2-5
D1-5
D3-5
P2”
D1-6
D3-6
D2-6
P1”
Equivalent to RAID 5 (3D+1P)
8 drives
Striping
RAID Groups and Volumes ETERNUS DX S3 / S4
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6. Improved Reliability with RAID 5+0
Fujitsu Training Documentation
Improved Reliability with RAID 5+0
RAID Groups and Volumes ETERNUS DX S3 / S4
RAID 5+0
One drive from each of the RAID 5 sets could fail without loss of data
After a single disk failure, RAID 5+0 has a shorter rebuild time than RAID 5 with the same number of data disks
RAID 5+0 has less disks per RAID 5 set and therefore less data disks to use for the re-calculation
Rebuild time will be long due to increase in number of drives
D3-1
D2-1
D1-1
D3-2
D2-2
D1-2
D3-3
D2-3
D1-3
RAID 5 (6D+1P)
D3-4
D2-4
D1-4 P3
D2-5
D1-5
D3-5 P2
D1-6
D3-6
D2-6 P1
7 drives
"D" = data area
"P" = parity area
Shorter rebuild time than 6D+1P
Small number of drives
RAID 5+0 (3D+1P) x 2
D3-1
D2-1
D1-1 P3
D2-2
D1-2
D3-2 P2
D1-3
D3-3
D2-3 P1
D3-4
D2-4
D1-4
P3”
D2-5
D1-5
D3-5
P2”
D1-6
D3-6
D2-6
P1”
4+4 drives
Equivalent to RAID 5 (3D+1P)
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

7. Improved Performance with RAID 5+0
Fujitsu Training Documentation
Improved Performance with RAID 5+0
RAID Groups and Volumes ETERNUS DX S3 / S4
RAID 5+0 writes faster than RAID 6 due to lower load in writing
RAID 6 needs more calculation time during write for double parities
RAID 5+0 can recover from double disk failure providing the disks fail from different RAID 5 sets
RAID 6 (6D+2P)
D3-1
D2-1
D1-1
D3-5
D2-5 P1
D3-2
D2-2
D1-2 P3
D2-3
D1-3 Q3
D2-4
D1-4
D3-3 P2
D1-5
D3-4 Q2
D1-6
D3-6
D2-6 Q1
8 drives
Striping
Able to recover from two concurrent drive failures
- Two parity drives are created - High loads when writing data
"D" = data area
"P" = parity area
RAID 5+0 (3D+1P) x 2
D3-1
D2-1
D1-1 P3
D2-2
D1-2
D3-2 P2
D1-3
D3-3
D2-3 P1
D3-4
D2-4
D1-4
P3”
D2-5
D1-5
D3-5
P2”
D1-6
D3-6
D2-6
P1”
8 drives
Faster data transfer with RAID5 (3D+1P) by striping
Equivalent to RAID 5 (3D+1P)
Recover from single drive failure in each RAID 5 (3D+1P)
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

8. Further Improved Reliability with RAID 6
Fujitsu Training Documentation
Further Improved Reliability with RAID 6
RAID Groups and Volumes ETERNUS DX S3 / S4
Tolerates two simultaneous hard disk failures in the same RAID Group independent of the disk position
RAID 5+0 can recover from double disk failure only providing the disks do not fail in the same RAID 5 set
This is advantageous when using large capacity hard disks that need a long time for rebuild
For example Nearline SAS disks
RAID 6 (6D+2P)
8 drives
D1-1
D1-2
D1-3
D1-4
D1-5
D1-6 P1 Q1
D2-1
D2-2
D2-3
D2-4 P2 Q2
D2-5
D2-6
D3-1
D3-2 P3 Q3
D3-3
D3-4
D3-5
D3-6
Striping
Able to recover from two concurrent drive failures
Uses two different parity blocks for the recalculation of missing data
"D" = data area
"P", "Q" = parity area
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

9. Comparison of RAID Levels (1)
Fujitsu Training Documentation
Comparison of RAID Levels (1)
RAID Groups and Volumes ETERNUS DX S3 / S4
Reliability 1)
Data efficiency 2)
Write performance 3)
RAID1
Good OK
RAID1+0
Very good
RAID5
RAID5+0
RAID6
RAID1+0
RAID1+0
Write performance
RAID5+0
Write performance
RAID5+0
RAID5
RAID5
RAID6
RAID1
RAID1
RAID6
Reliability
Data efficiency
1) 2) 3) On next page
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

10. Comparison of RAID Levels (2)
Fujitsu Training Documentation
Comparison of RAID Levels (2)
RAID Groups and Volumes ETERNUS DX S3 / S4
1) RAID1,1+0: Mirror all drives
RAID5: Able to recover from one drive failure on the same stripe
RAID5+0: Possible to recover two drive failures on the same stripe (Possible to recover one drive failure on a RAID array)
RAID6: Able to recover from two drive failures on the same stripe
2) User data area in all volumes when compared at each RAID array of the same user volume
3) Compared at 8KB random access performance
Relative superiority of sequential access performance varies depending on system configurations
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

11. Operation Principle of Fast Recovery
Fujitsu Training Documentation
Operation Principle of Fast Recovery
RAID Groups and Volumes ETERNUS DX S3 / S4
Fast Recovery offers a technology to shorten the rebuild time
Instead using a Hot Spare drive a reserved area to be used during rebuild is allocated in each drive of the RAID Group
When a drive failure occurs the reserved areas across the drives are used to hold the data of the failed drive
Unlike the traditional functionality of rebuild re-generating the data of the failed drive to the Hot Spare
Provides considerable reduction of rebuild time
Fast Recovery requires a copy-back after a drive has been replaced
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

12. ETERNUS DX Fast Rebuild - RAID6-FR1) (1)
Fujitsu Training Documentation
ETERNUS DX Fast Rebuild - RAID6-FR1) (1)
RAID Groups and Volumes ETERNUS DX S3 / S4
RAID6-FR is equal to RAID6 with striping
Uses double distributed parity
Provides high speed rebuild2)
Better performance achieved through striping of the FHS3)
Creation of a RAID6-FR takes less time than that of RAID6
Up to four drives can fail simultaneously
Capacity used for the reserved areas equals that of a Hot Spare 4) 3)
1) Available with firmware V10L20 onwards
2) Reduces the rebuild time of a 1 TB drive to 90 minutes from 9 hours
3) FHS means Fast recovery Hot Spare block that is distributed across all disks
4) P1 A,B,C is the first Parity block of these 3 data blocks
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

13. ETERNUS DX Fast Rebuild - RAID6-FR (2)
Fujitsu Training Documentation
ETERNUS DX Fast Rebuild - RAID6-FR (2)
RAID Groups and Volumes ETERNUS DX S3 / S4
In case of a drive error
The failed drive is degraded to status failed
The data of the failed drive is re-created to the FHS from the remaining drives
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

14. ETERNUS DX Fast Rebuild - RAID6-FR (3)
Fujitsu Training Documentation
ETERNUS DX Fast Rebuild - RAID6-FR (3)
RAID Groups and Volumes ETERNUS DX S3 / S4
A RAID6-FR is created like any other RAID Group
Except that the option "Create Mode" has to be set to "Manual" to enable the option RAID6-FR
Possible values are shown on next page
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

15. ETERNUS DX Fast Rebuild - RAID6-FR (3)
Fujitsu Training Documentation
ETERNUS DX Fast Rebuild - RAID6-FR (3)
RAID Groups and Volumes ETERNUS DX S3 / S4
With firmware V10L20 and later the following RAID6-FR configurations are supported
Within the GUI window "Create RAID Group" the following configuration options are selectable in the selection box "Fast Recovery Configuration"
The higher the number of usable disks, the less the cost in number of drives for a given amount of user storage capacity
Configuration
No. of Disks
No. of usable Disk
Recovery Speed
RAID6-FR (2x (3D+2P) + 1HS) 11 6
1.9 x vs. RAID6 (3D+2P)
RAID6-FR (2x (6D+2P) + 1HS) 17 12
2.1 x vs. RAID6 (6D+2P)1)
RAID6-FR (2x (9D+2P) + 1HS) 23 18
1.8 x vs. RAID6 (9D+2P)
RAID6-FR (2x (12+2P) + 1HS) 29 24
2.0 x vs. RAID6 (12D+2P)
RAID6-FR (4x (5D+2P) + 1HS) 20
4.4 x vs. RAID6 (5D+2P)
RAID6-FR (2x (13D+2P) + 1HS) 31 26
2.3 x vs. RAID6 (13D+2P)
RAID6-FR (6x (3D+2P) + 1HS)
7.2 x vs. RAID6 (3D+2P)
1) Fujitsu recommendation
RAID Groups and Volumes ETERNUS DX S3 / S4
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Copyright Fujitsu, Release June 2017

16. Fujitsu Training Documentation
Stripe Depth
RAID Groups and Volumes ETERNUS DX S3 / S4
Stripe depth can be set for RAID Group types 0, 1+0 and 5
Bigger stripe size improve random I/O performance by placing data stripes more often within a single drive instead of across drives
I/O request
Stripe size
RAID5 (with default Stripe Depth)
RAID5 (with expanded Stripe Depth)
RAID Groups and Volumes ETERNUS DX S3 / S4
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Copyright Fujitsu, Release June 2017

17. Distribute RAID Groups evenly across DE
Fujitsu Training Documentation
Distribute RAID Groups evenly across DE
RAID Groups and Volumes ETERNUS DX S3 / S4
RAID Group types 1, 1+0, 5, 5+0, 6 and 6FR
Fujitsu recommend that the disk drives be arranged to span different enclosures and SAS Backend Buses
For better reliability and with regard to the SAS Backend load balancing
DX100 S3 / 200 S3
DX500/600 S3
DX8700/8900 S3
1* SAS Backend Bus
2* resp. 4* SAS Backend Bus per CE
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

18. RAID Group Recommendation
Fujitsu Training Documentation
RAID Group Recommendation
RAID Groups and Volumes ETERNUS DX S3 / S4
For RAID5, RAID5+0, and RAID6, ensure that a single RAID group is not being configured with too many disk drives
If the number of disk drives increases, the time to perform data restoration from parities and Rebuild/Copyback also increases when a disk drive fails
Use of higher capacity disk drives will increase the time required for the drive rebuild process to complete
1) D = Data, M = Mirror, P = Parity
RAID Groups and Volumes ETERNUS DX S3 / S4
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Copyright Fujitsu, Release June 2017

19. Dynamic LUN Configuration
Fujitsu Training Documentation
RAID Groups and Volumes ETERNUS DX S3 / S4
Dynamic LUN Configuration
Logical Device Expansion
LUN Concatenation
RAID Migration
Dynamic LUN Expansion
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

20. Logical Device Expansion
Fujitsu Training Documentation
Logical Device Expansion
RAID Groups and Volumes ETERNUS DX S3 / S4
Expand capacity (free space) of a RAID Group by adding unused disk drives
RAID level can be changed
Unused disks not assigned to any RAID Group
Existing RAID Group RAID 5 (3+1)
Same RAID Group RAID 5 (5+1)
Expands
RAID Groups and Volumes ETERNUS DX S3 / S4
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21. Fujitsu Training Documentation
LUN Concatenation
RAID Groups and Volumes ETERNUS DX S3 / S4
LUN capacity can be expanded by using LUN concatenation
Consolidates unused areas in the same or across multiple RAID Groups for efficient use of drives
NOTE: After LUN Concatenation it may be necessary to adapt the Operating System and/or application to recognize the increased LUN size
Maximum LUN capacity is 128 TB
Minimum LUN capacity is 1 GB
Maximum number of LUNs that can be concatenated is 16
Able to mix different RAID levels
RAID Group 1
RAID Group 2
RAID Group 1
RAID Group 2
RAID GB x4
RAID GB x4
RAID GB x4
RAID GB x4
concatenate
LUN0　1.2 TB
LUN GB
LUN0 1.2 TB
LUN1 600 GB
Unused area 1.2 TB
RAID-Grp1
LUN2 with 1.8 TB
LUN2 600 GB
RAID Groups and Volumes ETERNUS DX S3 / S4
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Copyright Fujitsu, Release June 2017

22. Fujitsu Training Documentation
RAID Migration
RAID Groups and Volumes ETERNUS DX S3 / S4
Enables data to be moved between different RAID Groups without interrupting operation
Migrate existing LUNs from a RAID Group to a different one
Migration between different RAID levels
RAID migration to expand LUN capacity
Migration is transparent from server point of view
DX S3 / S4 and AF systems allow to migrate concatenated LUNs
Migrate data to a high reliable RAID level
Migrate data to large capacity drives
RAID GB
Unused 600 GB
LUN 0
RAID Group 1
RAID Group 2
Unused 600 GB
RAID GB
LUN 0
Mirroring
RAID Group 1
RAID Group 2
LUN 0
RAID GB
Unused 600 GB
RAID Group 1
RAID Group 2
Unused 300 GB
LUN 0
RAID GB
RAID Group 1
RAID Group 2
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

23. Dynamic RAID Group and LUN Expansion
Fujitsu Training Documentation
Dynamic RAID Group and LUN Expansion
RAID Groups and Volumes ETERNUS DX S3 / S4
The ETERNUS DX and AF Series is able to expand the capacity of LUN (Logical Unit Number) and RAID Group without stopping the operation
LUN0
New added drive
Current RAID Group
RAID 5 (4+1)
Expand
Logical device expansion
Expand RAID Group by "Logical Device Expansion"
RAID Group now
RAID 5 (5+1)
LUN0
Unused area
LUN Concatenation
LUN0
Expand LUN0 capacity by "LUN concatenation"
RAID Group RAID 5 (5+1)
RAID Groups and Volumes ETERNUS DX S3 / S4
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Copyright Fujitsu, Release June 2017

24. Fujitsu Training Documentation
Volume Creation (1)
RAID Groups and Volumes ETERNUS DX S3 / S4
The Web GUI of ETERNUS DX and AF Series provides a window ''Create Volume''
This is not usable for Flex Tier Volumes
RAID Groups and Volumes ETERNUS DX S3 / S4
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Copyright Fujitsu, Release June 2017

25. Fujitsu Training Documentation
Volume Creation (2)
RAID Groups and Volumes ETERNUS DX S3 / S4
The ETERNUS DX and AF Series support different type of volumes
Standard Volume most commonly used volumes
Wide Striping Volume capacity is distributed in stripes across (WSV) several RAID-Groups. Improved access speed with random I/O
Thin Provisioning Volume Virtual Volume assigned to Thin (TPV) Provisioning Pool (capacity on demand)
Snap Data Volume Special Volume with small phys. capacity (SDV) used in a volume copy session as destination volume. Per snap generation one SDV
Snap Data Pool Volume Special volume to expand the capacity of (SDP) the Snap Data Pool. All system wide SDVs are requesting on demand capacity chunks from this SDP.
RAID Groups and Volumes ETERNUS DX S3 / S4
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26. Fujitsu Training Documentation
Volume Creation (3)
RAID Groups and Volumes ETERNUS DX S3 / S4
The ETERNUS DX and AF Series support different type of volumes, continue
NAS Volume Virtual Volume type based on Thin Provisioning. Is only supported with "unified" installed.
Deduplication/Compression Virtual Volume based on Thin Provisioning.
Volume Volume has to be enabled for deduplication.
Flex Tier Volume Special Volume type used by Automated Storage Tiering. Is distributed accross 2 or 3 Sub-Tier-Pools and can be configured only with SF-Manager.
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017
Copyright Fujitsu, Release June 2017

27. Fujitsu Training Documentation
RAID Groups and Volumes ETERNUS DX S3 / S4
Copyright Fujitsu, Release June 2017