82899075 HP Storage Thin Provisioning

HP StorageWorks XP Thin ProvisioningThin Provisioning

M d l 06Module 06

u8443s E.00

© 2010 Hewlett-Packard Development Company, L.P.The information contained herein is subject to change without notice

HP Education Services

ObjectivesBy the end of this course, students should be able to: • State the advantages and the customer benefits of

implementing THP• Describe Thin Provisioning (THP) concepts and basic

functionalityfunctionality • List the main components of THP• List the specifications for THPList the specifications for THP• Describe the THP write process• Define V-VOL and THP Pool, and how they relate to THP , y

functionality.• Define and configure THP volumes

u8443sE.00 © 2010 Hewlett-Packard Development Company, L.P. 6 – 2

XP Thin Provisioning (THP) Overview

Features• HP StorageWorks XP Thin Provisioning (THP)

id h t ith i t l it l100GB

provides a host with virtual capacity volumes, allocating actual area in the volume from a pool of physical capacity Just-enough and Just-in-Time for a write request from the host.

• THP V-Volumes are backed-up by a pool of physical

Writes

THP V Volumes are backed up by a pool of physical storage

Benefits• No server reconfiguration required - configure future

it i t f tTHP Virtual

100GBVirtual Volume

capacity requirements upfront• Data is spread across all spindles in the pool

reducing or eliminating hot spots without the need for manual complex interleaving of volumesO l t ll d d & ti th it

VirtualVolumes

• Only actually needed & near time growth capacity needs to be purchased resulting in power and cost savings

• Fully supported with other XP array software like XP AutoLUN XP Business Copy and XP Continuous

u8443sd.01 © 2010 Hewlett-Packard Development Company, L.P. 6 – 3

AutoLUN, XP Business Copy and XP Continuous Access etc Physical capacity pool

THP main components (1 of 2)

THP pool volume• A raw LDEV whose capacity

contributes to the capacity of the pool

HostWrite Read/Write Read

HostWrite Read/Write Readcontributes to the capacity of the pool

THP pool• Where the data in THP volumes are

stored.

THP Vol.Host access

volumes

THP Vol.Host access

volumesstored.

• A collection of pool volumesTHP volume• Virtual volume that the host accesses

Capacity M

CacheCacheCapacity

M

CacheCache

• Virtual volume that the host accesses.• Each THP Virtual volume is

associated with a pool • Pool space is assigned when host first

THP PoolActual area for

THP h d

Shared MemoryDynamic Mapping

Table


Table

Monitoring


THP h d


Table


Table

Monitoring

• Pool space is assigned when host first writes to THP volume

Capacity monitoring• Manages free storage of the THP pool XP24K

Pool volumes

THP shared data

DMTbackuparea XP24K

Pool volumes

THP shared data

DMTbackuparea


• Manages free storage of the THP pool and reports used storage space to users.

XP24KXP24K

THP main component (2 of 2)

V-VOL Management table• Control information for Thin

Provisioning



Provisioning• Stored in dedicated Shared

Memory (2 copies)O

THP Vol.Host access

volumes

THP Vol.Host access

volumes

• Maps V-VOLs to pool pages

Management table backup Capacity M

CacheCacheCapacity

M

CacheCache

g p• Dedicated area stored on the

head pool volume• Stored on SVP Hard Drive when


THP h d


Table


Table

Monitoring


THP h d


Table


Table

Monitoring

• Stored on SVP Hard Drive when the XP is powered down

XP24K

Pool volumes

THP shared data

DMTbackuparea XP24K

Pool volumes

THP shared data

DMTbackuparea


XP24KXP24K

XP Thin Provisioning (THP) – Functionality Overview

12TB 16TB12TB 12TB 12TB 12TB

Traditional

OS visible 79TB

THP

OS visible 79TB 1.2TB 1.6TB1.2TB 1.2TB 1.2TB 1.2TB

LUNS: Physically

OS visible 7.9TB

LUNS: THP volumes

OS visible 7.9TB

1.2TB

0.1TB

1.6TB

0.15TB

1.1TB

0.1TB

1.5TB

0.15TB

1.2TB

0 04TB

1.3TB

0.06TB

y yprovisioned capacity

7.9TB(Virtual volumes)

0.6TB of actually 0. 0.04TB

No pool

ywritten data

2TB THP pool14TB f

LDEV LDEV LDEV LDEV LDEV LDEV LDEV LDEVProvisioned CapacityProvisioned Capacity

1.4TB free30% occupied


Array groups/Disk drives

LDEV LDEV LDEV LDEV LDEV LDEV LDEV LDEVLDEV LDEV LDEV LDEV LDEV LDEV LDEV LDEVp y

7.9TB316x 25GB LDEVs

p y2TB

80x 25GB LDEVs

THP performance optimization

• As servers write to the V-Vol data is written to the THP pool in 42MB chunks, which are distributed across all LDEVs in the assigned THP pool THP i i h d hi h i l LUN f• THP striping prevents hot-spots and guarantees high single LUN performance

• Max XP backend performance is not affected but CHA load may increase by 10 - 20%• Ideal for systems without a decent volume managers that can provide wide striping

THPV-Vol 1 V-Vol 2 V-Vol n

THPPool

Hi h d XP b

XP20/24000

High speed XP crossbar

DKA DKA DKADKA

Pooled


LDEVs

THP platform benefit summaryHost FS Volume configuration

simplificationPerformance optimization

Capacity usage optimization

HP UX JFS Yes Yes Yes_

Windows NTFS Yes Yes Yes

XFS Yes Yes Yes

Linux

XFS Yes Yes Yes

ext2 Yes Yes Yes

ext3 Yes Yes Yesext3 Yes Yes Yes

Solaris

UFS Yes Yes No. Data is written every 52MB

V FS Y Y YSolaris VxFS Yes Yes Yes

ZFS Yes Yes Yes


THP platform benefit summary (continued)Host FS Volume configuration

simplificationPerformance optimization

Capacity usage optimization

SNo. Data is

AIX

JFS Yes Yes written every 8MB

JFS2 Yes Yes Yes

VxFS Yes Yes Yes

ESX VMFS Y Y

Yes(IfESX VMFS Yes Yes (If

eagerzeroedthickis not used)

OpenVMS VMS Yes Yes Yesp

Tru64VFS Yes Yes Yes

AdvFS Yes Yes Yes


AdvFS Yes Yes Yes

NonStop NSK Yes Yes Yes

THP usage with other Program ProductsProgram Product Specification

Business Copy•For THP volumes, both P-VOL and S-VOL are supported. •For POOL volumes, neither P-VOL or S-VOL are supported

LUN Manager

LUSE

LUN Security

•A THP volume can be defined to a port like a normal volume•POOL volumes are not managed from this function

CVS

Server Priority Manager

DB Validator

Data Retention UtilityData Retention Utility

AutoLUN

Storage Partitioning This is supported for both THP and POOL volumes.

Continuous Access THP volumes are supported as P-VOL and S-VOLContinuous Access Sync/Async/Journal

THP volumes are supported as P VOL and S VOLPOOL volumes not supported as P-VOLs or S-VOLs

Snapshot* THP volumes supported as snapshot P-VOL

Cache LUN This cannot be set for either THP volumes or Pool volumes


External Storage Can be used as Pool-VOLs

THP BC usage details• A Pool volume is not supported for use as either the BC P-VOL or S-

VOL.

BC P-VOL BC S-VOL Specification

THP volume THP volume SupportedTHP volume THP volume •Supported.

THP volume Normal volume•Quick Restore is unavailable when the P-VOL is a THP volume and the S-VOL is a normal volume

Normal volume THP volume

This combination consumes the same capacity as thenormal volume (P-VOL)Pages containing zeros can be reclaimed after the copy


Pages containing zeros can be reclaimed after the copycompletes

THP usage with partitioning • It is not necessary to define a CLPR when defining a THP volume, but if

you do;– The THP volume and the THP pool it uses must be located in the sameThe THP volume and the THP pool it uses must be located in the same

CLPR– A THP pool cannot belong to more than one CLPR– A THP volume cannot belong to more than one CLPR.A THP volume cannot belong to more than one CLPR.

THPVOL

THPVOL

THPVOL

THPVOL

THPVOLVOL VOL VOLVOL VOL

THP Pool

THPPool

THP

u8443sE.00 © 2010 Hewlett-Packard Development Company, L.P. 6 – 12SLPR

CLPR CLPR

THPPool

THP operation sequence


THP pool• An XP24000 array has up to 128 THP pools

– Max volumes in a pool = 1024 LDEVs/pool (Minimum 8GB/Maximum 4TB)– Max V-VOLs in a pool = 8192 V-VOLs/pool (THP volumes)– V-VOL size = 46MB 4TB

• Each pool volume is divided into 42MB chunks, called a “PAGE” • Volumes can be dynamically added to a pool

– Data will be re-balanced across the pool (FW 60-05)• Pool volumes can not be removed• Alerts sent when thresholds reached• Volumes can not be shared by

Multiple pools

42MB1234.

VDEV slotpages

29

..

..

.


xx

30

Thin Provisioned volume implementation1. Create the THP V-VOL group – recommend one V-VOL

per V-VOL group2. Setup the V-VOL size3. Assign CU and LDEV-ID4 Att h th THP V VOL t l4. Attach the THP V-VOL to a pool5. Present THP V-VOL to a host

Note: The THP Volume are identified with an X notation toNote: The THP Volume are identified with an X notation to differentiate it from other XP volumes

Example (LDKC:CU:LDEV): • THP volume (00:FF:00 X) • SnapShot volume (00:EE:00 V)• External storage volume (00:AA:00 #)


External storage volume (00:AA:00 #)• Regular volume (00:00:00)

THP volume specifications

Item Specification Recommended configuration and restrictions

Definition Create from the V-VOL The V-VOL group for a THP volume cannot be Definition group for a THP volumeg p

shared with a Snapshot group

DeletionRemove the association with the host group and

the THP pool

When de-installing a THP volume from the pool, the free space in the THP pool increases, due to the LDEV format performed for the THP volumethe THP pool LDEV format performed for the THP volume

Maximum number of defined volumes Maximum 8192/pool

Capacity 46MB to 4TB

Em lation t pe OPEN VEmulation type OPEN-V

Threshold

When unassigned V-VOL capacity * threshold >

free space in pool an alert

•From 5% to 300%•Warning is given by SIM or SNMP Trap for each LUN


free space in pool an alert will occur

LUN. •Email alert can be configured

THP V-VOL Management tables• To process a host I/O the XP24000 must be able to:

1. Correlate the V-VOL logical address to a Pool ID and a V-VOL i thi lVOL in this pool

2. Convert the host address to the V-VOL logical address3 Convert the logical address to physical address on a given3. Convert the logical address to physical address on a given

page in the Pool4. Locate the physical LDEV that hosts the page5. Locate the I/O address position within the 42MB page6. Maintain the ECC RAID level for the pool LDEVs on the array

group levelgroup level• The V-VOL Management tables are stored in the VFS

SYS AREA within the Shared Memory.


Page slot control block• The page slot control block (PSCB) manages the 42MB page in a THP

pool as units. The storage area is called a “page”. When actual area is allocated in a THP volume, it is on a page basis., p g

• The XP needs to lookup Shared Memory to find out the:– Information for managing the address of the page #, and where the

page is on a given LDEVpage is on a given LDEV– Information for managing the data and free capacity in a page


THP Unallocated Reads• If the host issues a read I/O request to an area where a page has not yet

been allocated (from previous host write activity) in the THP volume, “0” data in the THP pool is responded to the request.p p q– When this process occurs, a new page is not allocated in the THP

volume (no additional capacity in the THP pool is consumed).


THP Unallocated Writes• If the host issues a write I/O request to an area where a page has not

yet been allocated in the THP volume, the XP allocates a page in the THP pool to the corresponding area in the volume.p p g

Host

THP-VOL Address TableWrite

THP-VOL Cache MemoryXXXX

PSCB Page N


SYS AREA (Shared Memory)THP POOL

THP allocated writes and reads• If the host issues a read or write I/O request to an area where a page

has already been allocated in the THP volume, the XP resolves the address of the area in the THP pool and then accesses the data.p

• The allocated page is overwritten; no new allocation occurs (no capacity in the pool is consumed).

THP-VOL Address Table

Host

Read/Write

THP-VOL Cache MemoryXXXX

VO


SYS AREA (Shared Memory)THP POOL

PSCB Page N

Insufficient THP pool free area • If a host issues a read I/O request to an area where a page has not yet

been allocated (from previous host write activity) in the THP volume, “0” data in the THP pool is responded to the request.p p q– If the pool is full, then an illegal request is returned.

• When this process occurs, a new page is not allocated in the THP volume (no additional capacity in the THP pool is consumed)volume (no additional capacity in the THP pool is consumed).

Access area I/O type Reported contentyp p

Page unassigned area

Read Illegal request

Write Write protectWrite Write protect

Page assigned areaRead Read enable

W it W it bl


Write Write enable

THP Thresholds• Pool Threshold (set for each pool):

– Percentage of used capacity to total capacity– Threshold 1 – User configurable 5-95%. Threshold 2 – 80%– SIM and SNMP trap sent when threshold reached

V VOL Threshold (set for each V VOL):• V-VOL Threshold (set for each V-VOL):– User configurable 5-300% Alert when unassigned

V-VOL Capacity *

V-VOL

assigned unassigned

Threshold > unassigned pool capacity

Pool

u8443sE.00 © 2010 Hewlett-Packard Development Company, L.P. 6 – 23unassigned

Pool

assigned

THP CHA performanceIf h ti f i l t f thi k b t i th d• If shooting for equivalent performance, think about using more paths and CHAs when planning for THP volumes, than you use for normal volumes.CHA h d i i d h i I/O f THP l• CHA overhead is increased when processing I/O for a THP volume

• The difference of overhead between #1 and #2 in the below table is large. – Unless it is clear that the processing is for the case #1, use #2 for

estimation (CHA usage rate increase is high).

ItemEstimated CHA

usage rate increase

Write to an area where page is allocated (update created file) 1.2 times

Write to an area where page is not allocated( t fil i fil i )

1.8 times


(create new file or increase file size)

Read (regardless if page is allocated or not to the area) 1.2 times

ThP space reclamationSome of the allocated pool space can be reduced by a simple deduplication mechanism known as “zero page” reclamation

• Initiated via the Web Console GUI. Use cases:– After data restore from volume level backups– After migration from standard to ThP V-VOL with

AutoLUN– After migration from “old storage” to XP with

External Storage and AutoLUN– Support added with 60-05 firmware

• Initiated from the host using the unmap option ofInitiated from the host using the unmap option of the WRITE SAME SCSI command– VxVM/VxFS version 5.x or later Storage Foundation

Thin Reclamation featureThin Reclamation feature fsadm –R /mnt or vxdisk rclm disk=<device>

– Support added with 60-06 firmware

THP Best Practices• The number of parity groups in a THP pool

• For better performance, include as many parity groups, across as many DKAs as possible in the poolmany DKAs as possible in the pool

• The number of parity groups can be estimated from I/Os or the I/O patterns of the THP volume that shares the pool

• RAID levels of parity groups that form the THP pool• RAID levels of parity groups that form the THP pool• As with normal volumes, determine RAID level for better

performance and reliability• The RAID level should be the same for all LDEVs assigned to a• The RAID level should be the same for all LDEVs assigned to a

pool group• How to use LDEVs in a parity group

Di id P it G i t # f LDEV th t t h b f d t• Divide Parity Group into # of LDEVs that match number of data disks. Ex. 7+1 divide into 7 LDEVs

• Use the entire parity group for the pool if at all possibleA id i i hi h I/O d di & h d t LDEV i th


• Avoid mixing high I/O demanding & hard to move LDEVs in the same parity group with THP pool Volumes. (example: SnapShot pool volumes & CA-JNL volumes)

THP Things to AvoidExcessive write processing from a host can result in the

sudden consumption of the capacity of the THP Pool• Defrag operations• Stress tests including I/O meter• Volume level restores


THP CONFIGURATION


THP pool creation (1 of 4)

2

1

2



1

2

4

3



1

3

4

2


2


22

3


1

Changing the Pool threshold

33

4


5

Increasing THP pool size

1

2

3


5

Deleting a pool

1

22


3

V-VOL Creation (1 of 3)

1 21

34

5


5

6

V-VOL creation (2 of 3)

152

43

5

1

7

6 8 9

1110


V-VOL creation (3 of 3)

3

1

2


Assocoate V-VOL with a pool (1 of 2)


Assocoate V-VOL with a pool (2 of 2)

Volume threshold:

5-300% (default 5%)


Assigning THP LUNs

THP volumes will have an “X” suffix


Viewing V-VOL Usage rates• Go Volume Manager V-VOL

• File Reports XP Thin Provisioning


XP ThP space reclamation


ThP LUN Expansion• On-line expansion of ThP LUNs• Support for Windows 2008

– December 2008 or later Firmware required

• Support for HP UX 11 31 and• Support for HP-UX 11.31 and OpenVMS– June 2010 or later Firmware

required• Use RAID Manager to grow ThP

volumesvolumes– raidvchkset vext option

• Set Host Group Option 40 for OS p pto be notified of V-VOL expansion


Releasing a V-VOL connection

• Remove all paths to V-VOL• Release V-VOL from PoolRelease V-VOL from Pool

- This returns V-VOL pages to the pool


Deleting a V-VOL group


LabLabactivity

Thi P i i iThin Provisioning



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82899075 HP Storage Thin Provisioning