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3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROITHIN PROVISIONINGTraditional (Fat) Provisioning—Dedicate on Allocation—Volume3PAR Thin Provisioning—Dedicate on DataVolumeWrittenDataPurchased Physical FERPOOLPurchased Physical CapacityFig. 04By breaking the traditional link between allocated and purchased capacity, Thin Provisioning allowsapplication costs to grow in direct accordance with application use and growth. Users can continueto request, and receive, desired amounts of capacity. But purchasing is now determined by actualutilization, so costs are less dependent on the ultimate “success” of the application. For IT there isan important additional benefit: the pain and complexity of provisioning is dramatically reduced.By allocating “generous” amounts of logical capacity to applications upfront, follow-on provisioningtasks and workflow are eliminated. Administrators can “allocate once,” safely and economically.(Mechanisms for monitoring and controlling planned and unplanned growth of data will bediscussed later.)R E D U C E D W O R K L OA D : F O L L O W- O N P R OV I S I O N I N ng Provisioning1Find an application that’s running out of space or performance2Determine how to add storage (extend a LUN, make new LUN)3Determine how much storage to addDetermine where in pool to obtain additional storage from4(taking performance and availability issues into account)5Allocate storage from pool6Set protection (LUN masks) of storage server so app can see it7Set switch zoning if necessary so app can see storage server8Add new storage to app LUN or form new app LUN9Configure O/S file system to handle bigger/new LUN10Configure application to utilize bigger/new LUN11Configure Backup system to back up bigger/new LUN12Replenish pool, if necessary (buy disks, build new lifiedEffortNo EffortRequiredFig. 057

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROILeveraging 3PAR’s 3-layer virtualization capabilities, the 3PAR InServ Storage Server presentsto hosts storage volumes (LUNs) of any size and service level. Meanwhile, physical capacity isintelligently dedicated only as the application writes data.This intelligence is shared across the InServ platform. Therefore, all data copies throughout thesystem can also be “Thin Provisioning aware.” For example, 3PAR Full Copy, a software facilityfor making full physical copies, will only consume the same physical capacity as the underlyingThin Provisioned volume. With 3PAR Virtual Copy, a copy-on-write snapshot technology, evenmore space is saved for local copies. With Virtual Copy, only the changes to the base volume orD E D I C AT E - O N - W R I T DEDICATES600 GB600 GB200 GB200 GBFig. 06to the copy (subsequent to the creation of the Virtual Copy) consume physical capacity. Typicallythis is only a fraction of the capacity of the base volume. Lastly, with 3PAR Remote Copy, copiesmirrored to other InServ Storage Servers (typically at remote sites) are just as space-efficient as thebase thin provisioned volumes.Note that for both Full Copies and Remote Copies, full physical capacity can be optionally dedicated.This is commensurate with the allocated logical capacity of the base thin provisioned volume.R E P L I C AT I O N O F W R I T T E N D ATA O N LYTHIN PROVISIONEDBASE VOLUME3PAR VITUAL COPY. 3 TB3PAR REMOTE COPY. 3 TB 138,000(at 0.03 per MB)Fig. 078

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROIIn summary, this platform-wide efficiency represents tremendous savings and resolves the technicalissue of replicated unwritten data, a key cause of the “allocated-but-unused” problem. Organizationsmay wish to leverage this efficiency by using local and remote copies in connection with moreapplications. For example, disaster recovery may now be feasible for applications that could notbe economically protected before.Summary Business BenefitsReduced Capital Expenditures3PAR Thin Provisioning reduces capital expenditures by eliminating disk expenditures immediatelyand by postponing them indefinitely (forever in the case of many applications). For applicationswhere local or remote on-line copies are used, capital savings are a multiple of the number ofcopies. For financial and IT managers, this assures much greater control of capital expenditures andlinks them directly to the return from a given application. As physical capacity is purchased andadded over time, users also leverage falling disk drive prices more effectively. Finally, with 3PARThin Provisioning, customers can reduce license fees paid for many storage software products, likeSRM tools.Lower Operating Expenses3PAR Thin Provisioning dramatically lowers operating expenses by conserving electricity andfloor space, otherwise expended for powering, cooling, and housing unnecessary disk drives. By“allocating once,” the IT organization is relieved of repeatedly performing onerous and error-pronetasks related to follow-on storage planning and provisioning. This results in workload and workflowreduction for administrators across the IT organization. Note that even the initial provisioning ofapplication-tailored volumes with the 3PAR platform is a mere matter of seconds. Thus, storagecan be intelligently provisioned for an application, for its lifetime, in a few brief seconds. Lastly,application downtime traditionally required to perform follow-on allocations, reconfigurations,and rebooting is eliminated.Accelerated Return on Investment3PAR Thin Provisioning addresses a final business concern—return on IT investment. As discussedearlier, Thin Provisioning enables a greater number of projects for less cost. Within a given budget,Thin Provisioning allows more applications to be deployed, with each one costing significantly lessthan before. Just as importantly, applications can be deployed faster. No longer is IT required towait until next quarter’s or next year’s budget allocation in order to deploy additional applicationsthat will generate return for their corporation. Nor are they required to wait until needed storage isplanned, sized, negotiated, procured, and installed before storage can be allocated. By maintaininga small buffer of physical capacity, IT can quickly and easily deploy new applications as and whenthey are needed. In either case, delays are eliminated and ROI is accelerated.9

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROIENABLE NEW PROJECTS AND REDUCE PROJECT RISKTraditional (Fat) aWrittenDataWrittenDataWritten Written BUFFERDataDataPOOLPROJECTPROJECTAThis Quarter(start projects,purchase storage)B10 TBsABEXTRAPROJECTCOMMON5 TBsPROJECTANext Quarter(evaluate projects)3PAR Thin nDatabig cost, small returnPVROENBIFALEDWritten WrittenDataDataEXTRAPROJECTENOVPRWrittenDatasmall cost, big/accelerated returnFig. 08Capacity is always available to start new projects, and administrator productivity has no dependencyon storage purchase, planning, or installation. In the end, many more projects with ROI potentialare initiated, and IT’s contribution to the overall business is increased.3PAR Thin Provisioning ArchitectureTo understand how 3PAR Thin Provisioning works, it is useful to first understand 3PAR’s approachto virtualization.3PAR Traditional Virtual Volume ManagementThe 3PAR InForm Operating System employs a 3-level mapping methodology similar to thevirtual memory architectures of server operating systems. The first level of mapping virtualizesphysical disk drives of any size into a pool of uniform-sized “chunklets” (256 megabytes (MB)each) and manages the redundant pathing to each chunklet and disk drive. The fine-grained natureof these chunklets eliminates underutilization of storage assets. Volumes can be sized preciselyand not according to large arbitrary increments. The chunklets’ fine-grained nature also enhancesperformance for all applications, regardless of their capacity requirements, by allowing distributionof chunklets across scores, or even hundreds of disks. Complete system access to every chunkletmeans no pockets of inaccessible storage.The second level of mapping associates chunklets with Logical Disks (LDs). This association allowslogical devices to be created with template properties based upon RAID characteristics and thelocation of chunklets across the system. LDs can be tailored to meet a variety of cost, capacity,performance, and availability characteristics, depending upon the service levels required. In addition,the first and second level mappings taken together serve to parallelize work massively across disks10

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROIVIRTUAL VOLUME MANAGEMENThost serverssee luns with tailoredperformance, availability,and capacityoltPvIrtuAl volumesof any size (1gb to 2tb each)logIcAl dIsKsintelligent combinations ofchunklets for tailored cost,performance, availabilitylogical disksarepre-dedicatedto support theentire logicalcapacityof virtualvolumesdWPhysIcAl dIsKsbroken into chunklets(256mb each)Fig. 09and their Fibre Channel connections. The third level of mapping associates traditional VirtualVolumes (VVs) with multiple LDs. VVs are virtual capacity representations that are ultimatelyexported to hosts and applications.With traditional Virtual Volume management, all of these mappings are set at VV creation. Thoughchanges may be made subsequent to creation (for example, to optimize the chunklet location),a full mapping exists at all times for all logical capacity of a base VV. Underlying chunklets andLDs (or portion of LDs) are thus “pre-dedicated” to a given VV, regardless of how much has beenwritten to that VV.(Please note that users are not required to manage these layers or associations. The InFormOperating System handles this automatically. Application-tailored Virtual Volumes are typicallycreated and exported to hosts in a just a few seconds.)3PAR Thin Provisioning Volume Management3PAR Thin Provisioning Volume Management removes the pre-dedication of physical capacity. Itbuilds on the 3PAR traditional volume management, but adds an intermediate function, knownas a Common Provisioning Group. The CPG function sits between the VV layer and the LD layer.Unlike traditional 3PAR virtual volume management where VVs are “backed” 100% by LDs, a CPGeffectively creates LDs from free chunklets on an as-needed basis. A CPG then maintains mappingsfrom its “owned” LDs to VVs that have been associated with it. A base VV that depends on a11

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROITHIN PROVISIONED VIRTUAL VOLUME MANAGEMENThost serverssee luns with tailoredperformance, availability,and capacityoltPvIrtuAl volumesof any size (1gb to 2tb each)common ProvIsIonIng grouPsmanage the creation anddedication of logical diskslogIcAl dIsKsintelligent combinations ofchunklets for tailored cost,performance, availabilitylogical disksare createdanddedicated asneeded tosupport the“written to”portion ofvirtualvolumesdWPhysIcAl dIsKsbroken into chunklets (256mb each)Fig. 10CPG is known as a Thin Provisioned Virtual Volume (TPVV). Note that just as with traditionalVV management, there is still massive parallelism of work over system resources, with chunkletsdistributed across scores, or even hundreds of disks.Thin Provisioned Virtual Volumes (TPVVs)Virtual capacity is represented to host servers and applications using TPVVs. Upon TPVV creation,a fraction of its exported virtual capacity is mapped to LD regions in the CPG. When applicationwrites are made to the TPVV, the InForm OS allocates space from pre-mapped LD regions in finegrained increments to accommodate the write. Over time, as available space in the LD regionsmapped to the TPVV runs low, additional capacity is automatically allocated by mapping newregions from LDs in the CPG.TPVVs behave like traditional VVs—the differences are transparent to the host. TPVVs can serveas base volumes for Virtual Copies, Full Copies, or Remote Copies. As with traditional VVs,application-tailored TPVVs are created and exported to hosts in a just a few seconds.Common Provisioning Groups (CPGs)As discussed, CPGs provide a buffer pool of LDs with an associated mechanism to automaticallydedicate LD capacity to mapped TPVVs as needed. Key attributes of CPGs include:12

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROI Fine-Grained Capacity Pooling: CPGs enable fine-grained, shared access to pooled logicalcapacity. Instead of pre-dedicating LDs, however small or large, to traditional VVs, a CPGallows multiple TPVVs to share a buffer pool of LDs. When a TPVV requires more dedicatedcapacity, a CPG automatically assigns logical capacity to the TPVV by mapping new regionsfrom its LD pool. So, while a CPG pool contains dedicated LDs, pooled resources remainundedicated to TPVVs until needed. Auto Growth: By default, a CPG is configured to create new LDs when the amount ofavailable LD space falls below a configured threshold. The initial buffer pool of LDs startsoff at a fraction of the exported virtual capacity of mapped TPVVs and auto-grows overtime as required by application writes. Effectively logical capacity growth tracks the growthin actual used capacity, allowing customers to purchase and install physical capacity asneeded over time. LDs can also be manually assigned to a CPG.Moreover, template LD properties (such as RAID characteristics and the chunklet location)are specified per CPG and are applied uniformly across the LDs in a CPG. To take maximumadvantage of Thin Provisioning, users may wish to group applications by service levels, whichcan then be associated with various CPGs. This not only enables users to meet their applicationrequirements, but also allows more volumes to share a CPG, and thus share a common amountof like buffer capacity.How 3PAR Thin Provisioning Works(1) CPG Creation: To take advantage of Thin Provisioning a user first creates a CPG. TemplateLD properties such as RAID characteristics and the location of chunklets across the systemare specified based on application requirements. In addition, the growth increment for LDsis specified in gigabytes (GB). The growth increment defines the size for initial LD creationas well as for subsequent growth of LDs as available capacity is used by the application.Alternatively, the user can manually admit LDs into the CPG and “opt out” of automatedlogical capacity growth by configuring the growth increment to zero. This may be desirablefor users who wish to pre-allocate a fixed amount of capacity for TPVVs and utilize theremainder for traditional VVs. Lastly, allocation warning and allocation limit for the CPGare specified based on application requirements and internal storage allocation policy.1 ) C P G C R E AT I O NLDCommon Provisioning GroupFig. 1113

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROI(2) TPVV Creation: To export virtual capacity to the host, the user creates a TPVV and exportsit as a VLUN to the host. During creation, the TPVV is associated with a CPG, which prededicates minimal logical capacity to it—a fraction of its exported virtual capacity.2 ) T P V V C R E AT I O NOLTPTPVVs-- -- ------LDCommon Provisioning GroupFig. 12(3) Capacity Allocation: As applications write to TPVVs, space is mapped in fine-grainedincrements from previously mapped LD regions to accommodate the writes. As the TPVVspace runs low, the CPG prepares for more writes by mapping new regions from LDs in theCPG to the TPVV.3 ) C A PA C I T Y A L L O C AT I O NOLTPNew writesTPVVsLDCommon Provisioning GroupFig. 1314

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROI(4) Auto-Growth: Once the available logical capacity in the CPG falls below a pre-configuredthreshold, the CPG automatically adds LDs in accordance with the specified capacity growthincrement. A CPG continues to auto-grow LDs, as needed, until either its Allocation Limitis reached or until sufficient physical capacity is not available to satisfy the requirements ofspecified LD characteristics.4) AUTO-GROWTHOLTPNew writesTPVVs----------LDLDCommon Provisioning GroupFig. 143PAR Thin Provisioning Alerts3PAR Thin Provisioning provides multiple categories of alerts that notify storage administratorsof important events: Allocation Warnings – Allocation Warnings provide a mechanism for warning storageadministrators when a specified logical capacity threshold is reached. An allocation warningcan be specified independently for TPVVs and CPGs. Allocation Limits – Allocation Limits provide a mechanism to prevent “run away”applications—applications that are in an abnormal state and continuously write data tothe storage device—from consuming logical capacity beyond the specified logical capacitythreshold. Allocation limits can be specified independently for TPVVs and CPGs. For aTPVV, once the allocation limit is reached, the logical capacity allocated to the TPVV stopsgrowing and new application writes fail. Similarly, for a CPG, once the allocation limit isreached, the automatic creation of new LDs, if configured, is disabled. New applicationswrites to TPVVs mapped to the CPG receive a write failure until the limit is raised. Used Physical Capacity – As available physical capacity across the 3PAR InServ Storage Serveris utilized by traditional VVs and/or TPVVs, multiple pre-configured alerts are generated thatprovide information about used physical capacity as a percent of total system capacity. ForCPGs configured with default LD characteristics, these alerts serve as an advance warningto the storage administrator to plan for and add necessary physical capacity. In the unlikelyscenario that effective physical capacity becomes used, the 3PAR InServ Storage Servernaturally prevents new writes from occurring until more capacity is added.15

3PAR Thin Provisioning Eliminating Allocated but Unused Storage and Accelerating ROIThese alerts combined with various alert delivery mechanisms (3PAR InForm CLI, 3PAR InFormGUI, SNMPv2 Traps, and email/page from 3PAR Central) enable storage administrators to manage3PAR Thin Provisioning in the way that suites them.Summary3PAR Thin Provisioning represents a new, cost-effective way to purchase and manage storage.Thin Provisioning solves the allocated-but-unused problem, saving millions of dollars in base andreplicated capacity, as well as related costs for housing, powering, cooling and software licenses.It provides a simple and powerful means of linking project cost directly with project outcomewhile requiring no behavioral changes from storage requestors. At the same, it directly addressesthe distorting effects of provisioning comple

solutIon: 3PAr thIn ProvIsIonIng 3PAR Thin Provisioning offers a simple solution to the problem of unused allocated capacity. Thin Provisioning allows IT departments to safely allocate to an application as much logical capacity as conceivably needed over its lifetime. Meanwhile, physical capacity is drawn from a common pool