HP 3PAR StoreServ 7450 2-node HP 3PAR StoreServ Storage Concepts Guide (OS 3.1 - Page 40

Growth Increment

As volumes that draw from a CPG require additional storage, the system automatically creates

additional logical disks according to the CPG's

growth increment

. The default and minimum growth

increments vary according to the number of controller nodes in the system.

Table 4 Default and Minimum Growth Increments

Minimum

Default

Number of nodes

8 GB

32 GB

2

16 GB

64 GB

4

24 GB

96 GB

6

32 GB

128 GB

8

In some it may be desirable to use a larger growth increment. However, a smaller growth increment

can prevent the CPG from automatically allocating too much space.

The optimal growth increment depends on several factors:

•

Total available space on your system.

•

Nature of the data running on the system.

•

Number of CPGs in the system.

•

Number of volumes associated with those CPGs.

•

Anticipated growth rate of the volumes associated with the CPGs.

NOTE:

The system may round up when creating logical disks to support virtual volumes and

CPGs, resulting in a discrepancy between the user-specified size or growth increment and the

actual space allocated to logical disks created by the system. For a detailed discussion of this

issue, see

“Logical Disk Size and RAID Types” (page 38)

.

Growth Warning

When the size of the volumes that draw from a CPG reach the CPG’s growth warning, the system

generates an alert to notify you of the CPG's increasing size. This safety mechanism provides the

opportunity to take early action that may prevent snapshot volumes associated with the CPG from

experiencing failures, causing host or application write failures, and exhausting all free space on

the system.

When setting growth warnings for CPGs, it is critical to consider the number of CPGs on the system,

the total capacity of the system, and the projected rate of growth for all volumes on the system.

The storage system does not prevent you from setting growth warnings that exceed the total capacity

of the system. For example, on a 3 TB system you can create two CPGs that each have a growth

warning of 2 TB. However, if both CPGs grow at a similar rate, it is possible for the volumes that

draw from the CPGs to consume all free space on the system before either CPG reaches the growth

warning threshold.

Growth Limit

If the volumes that draw from a CPG are allowed to reach the CPG’s

growth limit

, the system

prevents them from allocating additional space. This safety mechanism stops a runaway application

or volume from exhausting all free space available to the CPG and causing invalid (stale) snapshot

volumes and/or new application write failures for volumes associated with that CPG. However,

the storage system does not prevent you from setting growth limits that exceed the total capacity

of the system. For example, on a 4 TB system it is possible to create a CPG with a 5 TB growth

limit. Likewise, it is possible to create five CPGs, each with a 2 TB growth limit, etc.

40

Common Provisioning Groups

Section	Page
HP 3PAR StoreServ Storage Concepts Guide	1
Contents	3
1 Overview	7
HP 3PAR Storage Concepts and Terminology	7
Physical Disks	8
Chunklets	8
Logical Disks	8
Common Provisioning Groups	8
Virtual Volumes	8
Fully-provisioned Virtual Volumes	8
Thinly-provisioned Virtual Volumes	8
Physical Copies	9
Virtual Copy Snapshots	9
Exporting Virtual Volumes	9
HP 3PAR Software	9
HP 3PAR Software Products and Features	10
HP 3PAR Software Licensing Requirements	13
2 HP 3PAR Storage System Users	18
User Accounts	18
Local User Authentication and Authorization	19
LDAP User Authentication and Authorization	19
Domain User Access	19
3 Lightweight Directory Access Protocol	20
Overview	20
Active Directory	20
OpenLDAP	20
LDAP Users	20
LDAP Server Data Organization	21
LDAP and Domains	21
LDAP Authentication and Authorization	22
Authentication	22
Simple Binding	22
SASL Binding	22
Authorization	22
Authorization on Systems Using Virtual Domains	23
4 HP 3PAR Virtual Domains	24
Overview	24
Domain Types	24
Domain Type	25
Users and Domain Rights	25
Object and Domain Association Rules	25
The Default and Current Domains	25
5 Ports and Hosts	27
Overview	27
About Ports	27
Port Location Formats	28
Port Target, Initiator, and Peer Modes	29
Active and Inactive Hosts	29
Adding and Removing Hosts	29
Managing Host Personas	30
Legacy Host Personas	31
The Host Explorer Software Agent	31
6 Chunklets	32
Overview	32
Physical Disk Chunklets	32
Spare Chunklets	32
7 Logical Disks	34
Overview	34
Logical Disks and Common Provisioning Groups	34
Logical Disk Types	34
RAID Types	35
RAID 0	35
RAID 1 and 10	35
RAID 5 and 50	36
RAID Multi-Parity	37
Logical Disk Size and RAID Types	38
8 Common Provisioning Groups	39
Overview	39
Precautions and Planning	39
Growth Increments, Warnings, and Limits	39
Growth Increment	40
Growth Warning	40
Growth Limit	40
System Guidelines for Creating CPGs	41
Volume Types Associated with CPGs	41
9 Virtual Volumes	42
Overview	42
Virtual Volume Types	42
Administrative Volumes	43
Fully-provisioned Virtual Volumes	43
Thinly Provisioned Virtual Volumes	43
TPVV Warnings and Limits	44
Virtual Volume Online Conversion	45
Physical Copies	45
Virtual Copy Snapshots	46
Virtual Copy Snapshot Relationships	46
Copy-on-Write Function	47
Copy-of and Parent Relationships	48
Exporting Virtual Volumes	48
VLUN Templates and Active VLUNs	49
VLUN Template Types	49
Host Sees	49
Host Set	49
Port Presents	49
Matched Set	50
10 Reclaiming Unused Space	51
Overview	51
Reclaiming Unmapped Logical Disk Space from CPGs	51
Reclaiming Unmapped Logical Disk Space from Volumes	52
Automatically Reclaiming Unused Snapshot Space from Volumes	52
Manually Reclaiming Unused Snapshot Space from Volumes	52
Deleted Volume Snapshot Space	52
Logical Disks and Chunklet Initialization	52
11 Enhanced Storage Applications	53
Overview	53
HP 3PAR mySnapshot Software	53
HP 3PAR Dynamic Optimization Software	53
HP 3PAR System Tuner Software	54
HP 3PAR Thin Conversion Software	55
Assessment	55
Data Preparation	55
Zeroing Unused Space	56
Creating a Physical Copy	56
HP 3PAR Thin Persistence Software	56
HP 3PAR Thin Copy Reclamation Software	56
HP 3PAR Virtual Lock Software	57
HP 3PAR Adaptive Optimization Software	57
HP 3PAR Peer Motion Software	58
Data Encryption	58
Priority Optimization	59
Automatic and Transparent Failover	59
12 HP 3PAR Storage System Hardware	61
Overview	61
Identifying System Components	61
Physical Disks	63
Drive Cage/Enclosure Models	64
HP M6710 Drive Enclosure	64
HP M6720 Drive Enclosure	64
DC4 Drive Cages and Ports and Cabling	64
DC3 Drive Cage and Ports and Cabling	65
Controller Nodes	66
Port Numbering	67
HP 3PAR StoreServ 7000 Controller Node Numbering	67
HP 3PAR StoreServ 10000 Controller Node Numbering	68
T-Class Controller Node Numbering	69
F-Class Controller Node Numbering	70
13 HP 3PAR SNMP Infrastructure	72
Overview	72
About SNMP	72
SNMP Managers	72
The HP 3PAR SNMP Agent	72
Standard Compliance	73
Supported MIBs	73
MIB-II	73
Exposed Objects	74
System Description	74
System Object ID	74
System Up Time	74
System Contact Information	74
System Name	75
System Location	75
The HP 3PAR MIB	75
alertNotify Traps	76
14 The HP 3PAR CIM API	78
Overview	78
About SMI-S	78
About the WBEM Initiative	78
HP 3PAR CIM Support	79
Standard Compliance	79
SMI-S Profiles	79
Supported Extensions	79
CIM Indications	79
15 Comparing HP 3PAR to EVA Terms	80
16 Support and Other Resources	81
Contacting HP	81
HP 3PAR documentation	81
Typographic conventions	84
HP 3PAR branding information	84
17 Documentation feedback	85
Glossary	86

HP 3PAR StoreServ 7450 2-node HP 3PAR StoreServ Storage Concepts Guide (OS 3.1 - Page 40

Growth Increment, Growth Warning, Growth Limit, Table 4 Default and Minimum Growth Increments

Page 40 highlights