RCF Status Smooth operation over the course of

RCF Status • Smooth operation over the course of last week – No reportable outages of the Mass Storage System (HPSS), the Tape Libraries and the Network • PHENIX & RCF experts investigating rate limitation (cap at ~2. 4 Gbps) observed between Counting House and RCF – Issue understood and solved (see next 3 slides) – Data received from PHENIX & STAR Counting Houses was safely migrated to Tape • 30 min interference Sun/Mon night when other applications flooded Mass Storage System w/ requests – Looking at ways to implement request prioritization

PHENIX CH => RCF rate limit (from last Time Meeting) Back-to-back stores Causing long transfer tails 5 Gbps 2 Gbps Iperf test Steady-state rate out of buffer boxes Initial tests indicate that there is no limit imposed by network & HPSS data movers

Magnetic Disk Basics Arm Assembly Arm Head Spindle Cylinder Data Platter Track Read-ahead size is a critical parameter to achieve line-rate performance • In particular with sequential I/O • Caching in (memory) buffer

PHENIX Buffer Boxes (BB) sending Data to RCF Mass Storage System 5 Gbps Last Week 2 Gbps Source: Martin Purschke 7 th additional BB does not increase the transfer rate

Raw Data Volume collected & archived PHENIX Raw Data Physics 225 TB 3150 TB 3100 TB STAR Raw Data 240 TB 1300 TB 1250 TB 02/01/10

STAR Counting House RCF Network 4 Gbps 2000 GB/h Hourly Data Migration Rate To Tape (GB/hour)

PHENIX Counting House RCF 5 Gbps 2 TB/h 2000 GB/h Hourly Data Migration Rate To Tape (GB/hour)