© 2009 IBM Corporation Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. IBM DS3000, DS4000, and DS5000 Embedded Features and Functions Ryan Leonard Storage and Solutions Architect

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Caching  RAID controllers use cache for two purposes –Buffering write requests to media –Pre-fetching read requests from media  Battery backup for minimum of 72 hours  DS5100, DS5300 permanent cache backup (destage) Read request Write request  Cache slots allocated dynamically by controller based on demand  Flexible cache block sizes – 4KB, 8KB, 16KB

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Read caching  Intelligent read pre-fetch algorithm –Performs analysis of inbound read streams for sequentiality –Pre-fetch cache hits extend amount of data prefetch –Will recognize ascending, descending, and ‘sparse’ patterns CacheDisk Host read request

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Write caching  Cache mirroring for data protection  Write-back and write-through modes  Demand-based and age-based flushing  Full-stripe write-through –Allows full-stripe writes to bypass the cache mirroring process and write-through to media RAID 5, 4+P Segment Stripe

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 So what is a “hardware XOR” anyway?  An XOR is used in RAID 5 to calculate parity –The XOR calculation can be performed in either hardware or software –Similar operation for RAID 6 ‘q’ information A1 XOR A2 XOR A3 = Ap  But more importantly…  The hardware XOR functionality is embedded in a specialized cache memory controller –Allows DMA transfers from host and drive side to cache independently with no processor interrupts A1 B1 C1 Dp A2 B2 Cp D1 A3 Bp C2 D2 Ap B3 C3 D3

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Configuration Flexibility  Immediate Availability Format (IAF)  Dynamic Array Expansion (DAE)  Dynamic Volume Expansion (DVE)  Dynamic RAID Migration (DRM)  Dynamic Segment Sizing (DSS)  HotScale  DACstore

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Immediate Availability Format  A given logical drive, once defined via the Storage Manager, is available almost instantaneously for usage Array 1, RAID 5 3+P 100MB initialization region  Further initialization continues in background while host reads/writes are accepted LUN A

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Dynamic Array Expansion (DAE)  Dynamically grow a given array / RAID set –Host I/O continues during modification operation RAID 5, 3+P  No maximum on RAID 0 or 10 on DS3/4/5000 (7.10 or higher)  Maximum of 30 drives per RAID 5/6 array

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Dynamic Array Expansion (DAE)  Dynamically grow a given array / RAID set –Host I/O continues during modification operation RAID 5, 4+P  No maximum on RAID 0 or 10 on DS3/4/5000 (7.10 or higher)  Maximum of 30 drives per RAID 5/6 array

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Dynamic Volume Expansion (DVE)  Dynamically grow a given logical drive / LUN within an array –Host I/O continues during modification operation  Logical drives >2TB supported (w or higher)  Available on DS3000 via CLI or Script Editor Unused CCCCBBBBAAAA RAID 5, 3+P - 3 LUNs defined, A, B and C

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Dynamic Volume Expansion (DVE)  Dynamically grow a given logical drive / LUN within an array –Host I/O continues during modification operation  Logical drives >2TB supported (w or higher)  Available on DS3000 via CLI or Script Editor Unused CCCCBBBBAAAA RAID 5, 3+P - 3 LUNs defined, A, B and C CCCC B BBB AAAA

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Dynamic RAID Migration (DRM)  Dynamically modify an array from one RAID level to another –Host I/O continues during modification operation  Any to any modification  Additional drives may be required to complete operation  Available on DS3000 via CLI or Script Editor RAID 5, 3+P A1 B1 A2 B2 A3 Bp Ap B3

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Dynamic RAID Migration (DRM)  Dynamically modify an array from one RAID level to another –Host I/O continues during modification operation  Any to any modification  Additional drives may be required to complete operation  Available on DS3000 via CLI or Script Editor A1 B1 A2 B2 A3 Bp Ap B3 A1 A2A1’ A2’ B1B2B1’B2’ RAID 10, 2+2

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Dynamic Segment Sizing (DSS)  Dynamically modify the segment size of a specific logical drive –Host I/O continues during modification operation  Amount of data written to a drive before moving on to the next drive in the stripe  Typically used in performance tuning  Available on DS3000 via CLI or Script Editor Drive 1Drive 2 Drive 3 Drive 4 RAID 5, 3+P 64KB

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July KB Dynamic Segment Sizing (DSS)  Dynamically modify the segment size of a specific logical drive –Host I/O continues during modification operation  Amount of data written to a drive before moving on to the next drive in the stripe  Typically used in performance tuning  Available on DS3000 via CLI or Script Editor Drive 1Drive 2 Drive 3 Drive 4 RAID 5, 3+P

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 HotScale  Addition of physical storage capacity –Host I/O can continue during drive / enclosure addition  On-demand scalability DS3400

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 HotScale  Addition of physical storage capacity –Host I/O can continue during drive / enclosure addition  On-demand scalability DS3400

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 DACstore  512MB reserve for drive metadata –Array can be ‘exported’ and/or ‘imported’  Data intact relocation Old Controllers

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 DACstore  512MB reserve for drive metadata –Array can be ‘exported’ and/or ‘imported’  Data intact relocation Old Controllers New Controllers

Statements of IBM future plans and directions are provided for information purposes only. Plans and direction are subject to change without notice. System Storage July 2009 Reliability, Availability, Serviceability (RAS)  MediaScan –Performs scan of physical media for unreadable blocks –All instances are logged  Advanced Rebuild –Complete a drive rebuild even after encountering unreadable sectors  Enhanced Disk Drive Predictive Fault Analysis –Monitors and logs recoverable or medium errors –May fail drives preemptively if thresholds are surpassed  Concurrent controller firmware updates  Event logging and reporting –Critical alerts via and/or SNMP