Proposed Storage Area Network Facilities

For Discussion

Motivation

University investing SRIF funds in SAN technology to help support future e-science projects

Other University’s doing the same e.g EdinburghOpportunity to review University’s overall storage requirements

On Campus most disk storage is provided via Direct Attack Storage (DAS)

Problems with DAS

File store growth exponential leading to:Proliferation of hardwareSub-optimal provisionInefficient delivery

Close coupling leads to single points of failureBackup regimes become stressed, costly and labour intensiveDisaster recovery procedures become expensive or impractical

Discussion

It is proposed that a storage consolidation strategy based on Storage Area Network (SAN) technology would provide a flexible, manageable and cost effective solution for the majority of the University’s file store requirements

Storage Consolidation

Storage consolidation is about centralising and sharing storage resources amongst a variety of file and application servers The management of storage resources is separated from the management of servers by establishing a network that removes the physical mapping of storage devices to physical serversThis network allows isolated islands of storage to be pooled together and allocated to servers in a more flexible fashion

Storage Consolidation BenefitsHeterogeneous environmentProtects against SPFStorage aggregation into virtual poolsLess complex managementLower admin costsMore suited to DRPotential for server consolidationSignificantly improves backup restore capabilitiesImproves data security, accessibility and availability

Storage Consolidation Architectures

Enterprise RAID operates at Block level Storage Area Network (SAN) operates at Block levelNetwork Attached Storage (NAS) operates at File level

Enterprise RAID

Storage Area Network (SAN)

Network Attached Storage (NAS)

Future TrendsIntegrate the benefits of different architectures into a common model by enhancing the SAN architecture with NAS head functionality and Fabric extension capabilitiesNAS heads provide:

SAN attached dedicated serversResilience through ClusteringHigh performance interfaces

Fabric extension via iSCSI, FC/IP and iFCIP provideIntegration of SAN islandsLower cost server to SAN connectionsAbility to extend SAN connectivity

Bringing it together

Potential SAN Benefits for the University

More efficient use of storage resourcesLess systems administration effortResilience via fault toleranceDisaster recovery plansBackup and restore operationsServer consolidation and resilienceCore service provision – Directories, E-Mail, CSCE, SSD, Samba etcResearch projectsFaculty/Department Block and File level requirements

Proposed SAN ModelA core fabric spanning 2 sitesA number of FC edge switches linked to the FC coreA number of disk arrays providing the storage requirements for:

Research projectsMirroringCore servicesOther applications

A number of servers connected via FC Host Bus Adaptors (HBAs) An enterprise class backup facility NAS heads for file sharing functionalityiSCSI support for fabric extension to non FC attached clientsFC/IP support for native fabric extension

Proposed SAN Model

What factors need to be addressed when considering a SAN solution?

Fabric costsFabric Design

Switch costsHBA costsFibre provisionManufacturers limits

Vendor and OS support

Fabric extensionNAS headsiSCSI and FC/IP

SAN managementDisk groupingSecurityPerformance monitoring

What factors need to be addressed when considering a SAN solution?

Disk virtualisation requirementsVirtualising file systemsBackup Regimes

Type – Snapshot, Full and IncrementalExtent – wont be able to backup all SAN storageMedia – Tape, staging disk then tapeCosts – hardware and media

Fabric Connection Guidelines

Not an open SANRestrict to manageable set of proven hardware compatible systems

FundingInitial SRIFRequires significant investment over timeWho pays?

Alternative SolutionsLower cost IP/SAN solutions emerging based on

Standard hardwareOpen source OS’s iSCSI over existing campus networks

ExamplesOpen source NAS with future SAN support http://www.techworld.com/news/index.cfm?fuseaction=displaynews&NewsID=615 Open source NAS appliance http://www.nwfusion.com/reviews/2003/0428nasrev2.html SANmelody - http://www.datacore.com/products/prod_SANmelody.asp