Presentation given at the Storage Visions Conference in Las Vegas in 2007

1. Long-term storage of
disk drives for archival
and other applications
Ronald Watts, Michael Ries,
Troy Merrell, Andrei Khurshudov

2. The History of Long-term Data Storage
Causes of Deterioration
• Temperature (Alternate
freezing and heating)
• Natural or artificial light
• Corrosion
• Rainwater
Storage media: charcoal and dirt on stone
• Inferior storage
Data type: analog (image) medium
Storage life: >17,000 years
• Well preserved in
(in a sealed dry cave)
favorable storage
conditions!
1/17/2007 Andrei Khurshudov
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WW Advanced Reliability

3. The History of Long-term Data Storage - 2
Causes of Deterioration
• Chemical contamination (smoke from
candles, torches and braziers)
• Physical contamination (greasy dust,
sediment from rain, glue, animal varnish,
and residue from past cleanings had built
up on the frescoes)
• Handling (cracking)
• Higher quality
storage media
• Higher rate of
Sistine Chapel, Vatican City, 1512
degradation due to
Storage media: Paint on stone
detrimental storage
Data type: analog (image)
conditions!
Storage life: < 500 years
(initial customer request: intended to last … forever)
1/17/2007 Andrei Khurshudov
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4. The History of Long-term Data Storage - 3
Causes of Deterioration
• Temperature (fire)
• Chemical
contamination (smoke)
• Water damage
• Similar storage
media
Name: ‘Diamond Sutra’ (the world’s earliest
• Drastically
complete survival of a dated printed book), AD
868.
different storage
Storage media: ink on paper
conditions!
Data type: analog (images, characters)
Storage life: >1,100 years (sealed in a cave)
Name: ‘War With Devils’, 1797
Storage media: ink on paper
Data type: analog (images, characters)
Storage life: <200 years (no special storage efforts)
Observation:
• Storage conditions are critically important for reliable data storage !
1/17/2007 Andrei Khurshudov
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5. The Never-Ending Evolution…
Drive capacity increases every year
Greater capacity creates new applications and opens new
markets
Many new applications and markets require longer
storage time
Longer storage time brings new failure modes and new
reliability challenges
Reliability challenges are resolved via better
understanding and “design for reliability” efforts
Better design improves reliability and helps increasing
capacity
Drive capacity increases every year
…
1/17/2007 Andrei Khurshudov
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6. Long-Term storage hardware trends
Data Tape Cartridge
Data Disk Drive Cartridge
More changes in the future!
Traditional storage hardware
Disk Drive Storage
VCR Tape Storage
Tape Backup Disk Drive Backup Tape Library Disk Drive Library
1/17/2007 Andrei Khurshudov
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7. Current Record Retention Requirements
Minimum Retention Period Requirement on Media (years)
0 5 10 15 20 25
Automotive
industry
Pharmaceutical
industry
Healthcare
Financial
services
Government
Agencies
Sarbanes-Oxley
• Mandated record retention periods differ dramatically from 3 to 20
years depending on the application
• High HDD long-term reliability is required to cover all applications
• We should expect even longer retention periods to be required in the
future
1/17/2007 Andrei Khurshudov
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8. Selected long-term storage HDD applications
HDD Long-Term Storage Applications
Automotive Institutional Security
Archival
CE
• Video Surveillance
• Pharmaceutical
• Corporate data • GPS
• Music (MP3, etc)
• Security Database
• Medical
• Data libraries • Black Box
• Movies
• Legal/evidence
• Life Sciences
• MAID Arrays • Mobile internet
• Set-top boxes
applications
• Academics
• Tape Replacement • Entertainment
• Photos
applications • Financial services
• Mobile Video
• Emails
•Off-site storage Recording • Government Agencies
• Games
•Disaster Recovery • Spare parts • Sarbanes-Oxley
• Family financials
• Other applications
• Backup
• Etc.
* Appeared in the last 5 years
• Different applications bring different requirements and different
storage environments: from an unheated garage to a vault with
climate control
• New applications are introduced continually
1/17/2007 Andrei Khurshudov
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9. World climate’s impact
Summary:
Temperature and humidity vary dramatically across the world during the
year (from almost 0% RH to 100% RH and from -30oC to +40oC)
Need to design products for a wide range of T/RH
Controlled storage environments aren’t always possible
Need to design for the worst case
Reliability will vary with the location (isolated populations)
Future: Might need to optimize design for a specific geographic location
Knowledge of the world climates and drive response to the external
environments are critical for successful design
1/17/2007 Andrei Khurshudov
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10. Seagate’s “Design for storage” program goals
• Understand environmental effects on long-term storage
• Establish importance of major stressors
• Develop mitigation means
• Develop a reliability prediction model for long-term storage
• Sample question: What is the reliability after 7 years of storage at
oC/65% RH?
50
• A: Under these conditions, population reliability will be 99.9%
with 90% confidence
• This model covers a wide range of conditions
• Develop an accelerated storage test methodology
• 20 years in 20 days?
• Develop recommendations for long-term storage conditions
• Recommend acceptable storage environments and durations for new
markets: CE Institutional
Archival Security, etc.
Automotive (EE25 series)
1/17/2007 Andrei Khurshudov
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11. Factors impacting long-term storage reliability
Time
In general, increases opportunity for any degradation
Temperature
Accelerates physical and chemical processes exponentially
Impacts thermal decay rate
Humidity
Accelerates corrosion and other processes
External contamination
Might result in both external and internal damage
Handling (shock and vibration)
Causes non-operational mechanical damage
Stray magnetic fields
Cause data erasure
1/17/2007 Andrei Khurshudov
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12. Long-term Reliability vs. Environment
4.0%
Example Unfavorable storage conditions
3.5%
3.0%
2.5%
Fail %
2.0%
1.5%
1.0%
Average storage conditions
0.5%
Optimized
Optimal storage conditions
0.0%
HDD
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
Storage Time, Year
Long-term reliability is a strong function of both Drive Design and
Storage Environment
Even a well-designed drive will be compromised by improper/uncontrolled storage conditions
This applies to all storage media types including disk drives
Seagate has developed a sophisticated model capable of predicting
required storage conditions for any given reliability requirement and
duration
Sample question: what temperature and humidity conditions are required to maintain the
99.5% reliability for, say, 3.5 years?
1/17/2007 Andrei Khurshudov
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13. Conclusions
Disk drive is a medium for long-term storage with unique
combination of direct access to data and low $/GB
Long Term HDD Reliability is a function of both drive
design and storage conditions
Storage conditions must be optimized based on reliability requirements and storage
duration
Seagate has developed the optimization methodology
Customer storage environment has strong influence on long-term drive reliability
Even for the HDD that was optimized for long-term storage, extreme environmental conditions will
impact long-term reliability
Seagate is uniquely positioned to work with the customers
requiring long-term storage:
Seagate has a dedicated R&D program focusing on “Design for Storage”
Know how to design products for high reliability
Developed highly-accelerated test methodologies
Know how to select optimal storage environments for each application
1/17/2007 Andrei Khurshudov
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