Review of IDEMA Reliability Symposium of May 15, Jon G. Elerath, Ph.D. September 17, 2008

Transcription

1 Review of IDEMA Reliability Symposium of May 15, 2008 Jon G. Elerath, Ph.D. September 17, 2008

2 Agenda What reliability symposium? Summary of companies and topics Selected topics (HDD and SSD) 1. Failure, system response and metrics 2. Failure modes, mechanisms, causes 3. Measured field reliability 4. Trends in field reliability 5. Testing Conclusions Future standards Slide availability

3 IDEMA Technical Symposium, May 15, 2008 Hard disk and solid state drive reliability Speakers Dr. Jon Elerath, NetApp: The Physics, Mathematics, and Statistics of Reliability Assessment Pat Wilkison, STEC-Inc.: Solving the Challenges of SSD Reliability Ravi Chari, Sun Microsystems: Determining the Reliability of Disk Drives -Current Challenges Jason Pollock, Hewlett Packard: Hard Disk Drive Reliability - HP Experience and Expectations Dave Verburg, IBM: IBM Disk Drive Reliability Dr. John McNulty, DfR Solutions: Current Concerns Regarding Solid State Drive Reliability Dr. George Tyndall, Samsung: Role of the Head-Disk Interface in HDD Reliability Dr. Arkady Kanevsky, NetApp: Why Disks Fail David James, Fujitsu Computer Products of America: "Hard Error"-An Examination of Disk Drive Failure Modes David Jackson, Cool Clean: Changing the Game Rules with CO2 Ed Dawson, Flexstar: Standardizing and Testing for SSD's and HDD's Steve Grenyer and Darren Beck, Xyratex International: The Evolving Stable Product: A Contradiction of Terms Steve Hetzler, IBM: System Impacts of HDD & Flash Reliability

4 IDEMA Technical Symposium, May 15, 2008 Hard disk and solid state drive reliability Corporate participation Jon Elerath, NetApp: The Physics, Mathematics, and Statistics of Reliability Assessment Pat Wilkison, STEC-Inc.: Solving the Challenges of SSD Reliability Ravi Chari, Sun Microsystems: Determining the Reliability of Disk Drives -Current Challenges Jason Pollock, Hewlett Packard: Hard Disk Drive Reliability - HP Experience and Expectations Dave Verburg, IBM: IBM Disk Drive Reliability Dr. John McNulty, DfR Solutions: Current Concerns Regarding Solid State Drive Reliability Dr. George Tyndall, Samsung: Role of the Head-Disk Interface in HDD Reliability Dr. Arkady Kanevsky, NetApp: Why Disks Fail David James, Fujitsu Computer Products of America: "Hard Error"-An Examination of Disk Drive Failure Modes David Jackson, Cool Clean: Changing the Game Rules with CO2 Ed Dawson, Flexstar: Standardizing and Testing for SSD's and HDD's Steve Grenyer and Darren Beck, Xyratex International: The Evolving Stable Product: A Contradiction of Terms Steve Hetzler, IBM: System Impacts of HDD & Flash Reliability

5 HDD Symposium Summary Elerath- NetApp Chari-Sun Pollock-HP Verburg-IBM McNulty-DfR Tyndall- Samsung Kanevsky- NetApp James- Fujitsu Jackson- Cool Clean Dawson- Flexstar Grenyer- Xyratex HDD Field Exp Reliability (Quantified) Reliability Trends 4 4 Failure modes/mech/causes Test/Return Process 3 3 NTF Rates 3 3 System Fault Impact & Management Definition of failure Integration vs. Field 3 3 Mobile and Desktop X X High-end X X X X Data collection & analysis 1 Reliability Models X X Hetzler-IBM Flash/SSD Error rates 3 Test/verification issues 5 5 Failure mechanisms/modes/causes 2 2 Reliability models X Testing 5 5

6 HDD Failures and System Responses Source: Ravi Chari, Determining the Reliability of Disk Drives, Sun Microsystems System Fault Management is KEY challenge ahead (Chari) Fitness for use is greater than just AFR SMART is an unfulfilled promise When is a proactive reconfiguration a drive failure?

7 HDD Failures and System Responses Source: Arkady Kanevsky, Why Disks Fail, NetApp

8 What is the Definition of Failure? Source: Jon Elerath, The Physics, Mathematics and Statistics of Reliability Assessment, NetApp Levels of HDD reliability (Verburg-IBM) data loss misbehaving HDDs operational failure

9 Failure Modes, Mechanisms and Causes Source: Dave Verburg, IBM Disk Drive Reliability, IBM (used with permission) Proportionate summary of failure reasons Not applicable to any particular program or platform Make sure bus chips and adapters are not contributing to drive removals Improve event logging and other tools CND FW Improve Cleanliness, other head/media actions As drive improves, NDF improves NDF Head/Media NDF = No Defect Found CND = Could not Duplicate Card/Other Mechanical FW = Firmware

10 Failure Modes, Mechanisms and Causes HDDs in top 2-3 for warranty returns (HP) NFF - single largest contributor across all segments Handling - primarily notebook Contamination...the single largest HDD caused reason (HP) NDF/CND/FW greatest causes for removal (Verburg-IBM) Failure of the head-disk interface is found to be the dominant factor impacting HDD reliability (Samsung) in highly accelerated stress tests 64% were HDI related in RDT 75% were HDI related from field, 35.4% were HDI related 60% NTF/CND (Sun)

11 Failure Modes, Mechanisms and Causes Mobile failures similar for integration and field (Fujitsu) handling damage NTF/CND HDD build issues (incl. contamination) component failure NDF:CND = 3:1 (Fujitsu) NDF due to misdiagnosis CND due to electrical issues high-fly writes

12 Measured Field Reliability (HDDs Only) Numeric Values (High end HDDs) 0.6%-2.5% (Elerath-NetApp) 0.5% (verified) AFR in 2008 (Chari-Sun) 1.2% ARR in 2008 (Chari-Sun) 0.73% for Enterprise at 1 year (Xyratex) 1.04% ATA at 1 year (Xyratex)

13 Trends in Field Reliability (HDDs Only) Field ARRs steadily decreasing (Nov 06 Mar 08) (Pollock-HP) SAS 50% improvement over pscsi in Nov 08 (Pollock-HP) HDD reliability is improving (Verburg-IBM) Source: Dave Verburg, IBM Disk Drive Reliability, IBM (used with permission) Drive failure rate History Drive Failure rate High End drives vs entry drives 10-20% improvement per year High End Entry Why the difference? Duty Cycle Reject Criteria/Health checks Environment Disk space utilization System interactions Etc.

14 Trends in Field Reliability (HDDs Only) HDD reliability improving (Chari-Sun) AFR 1.1% 0.5% ARR 2.0% 1.2% Source: Ravi Chari, Determining the Reliability of Disk Drives, Sun Microsystems

15 Testing Classical reliability benchmarks are (Sun) being questioned getting harder to demonstrate do not address user experience Arguably, increasingly meaningless

16 Solid State Drives Will be nearly impossible to demonstrate reliability for current UER s needed for flash, not even addressing the surface phenomenon (Hetzler-IBM) Customer owns reliability (Hetzler) SSDs should be treated very differently from HDDs (Hetzler) Example Error Rate Surface Error Rate Multiplier 1E+05 1E+04 1E+03 1E+02 1E+01 1E+00 1E+06 1E+05 1E+04 1E+03 1E+02 1E+01 1E+00 Write Age (S) Source: Steven Hetzler, System Impacts of HDD and Flash Reliability, IBM

17 Solid State Drives FLASH/SSD test verification issues (Hetzler-IBM) SSDs have different failure modes/mechanisms, so tests must be different. (Flexstar) HDD manufacturers can t agree on a standard reliability test; It may not be possible to compare HDD to SSD if tests are significantly different (JGE editorial remark) Believe AFR will be more predictable in SSDs because mechanical fr mechanisms are eliminated. (Flexstar) Comprehensive SSD presentation (STEC) was unavailable for info extraction for this presentation

18 Solid State Drives Critical Issues in Solid State Drive Reliability (DfR) Single (SEU) and multi (MEU) event upsets Neutron and alpha particle-induced failures Other forms of IC degradation Failure: dielectric breakdown (TDDB), electro-migration (EM) Drift: negative bias temperature inversion (NBTI), hot carrier injection (HCI) Advanced packaging issues Off-die interconnect reliability Emphasis on: Failure mechanisms Scaling effects to deep sub-micron feature sizes

19 Concluding Remarks Outstanding 1-day Reliability Symposium Great participation (numerous integrators) High quality presentations and excellent technical depth IDEMA is pursuing reliability standards in conjunction with JEDEC and SNIA Slides available from IDEMA at

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