Energy Efficiency and Storage Flexibility in the Blue File System Edmund B Nightingale Jason Flinn...
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Energy Efficiency and Energy Efficiency and Storage Flexibility in Storage Flexibility in the Blue File System the Blue File System Edmund B Nightingale Jason Flinn University of Michigan
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Transcript of Energy Efficiency and Storage Flexibility in the Blue File System Edmund B Nightingale Jason Flinn...
Energy Efficiency and Storage Energy Efficiency and Storage Flexibility in the Blue File SystemFlexibility in the Blue File System
Edmund B Nightingale
Jason Flinn
University of Michigan
The Blue File System 22
Towards Ubiquitous Data AccessTowards Ubiquitous Data Access• Pervasive computing: anywhere anytime any device
– Ubiquitous WiFi access
– Mobile storage
Barriers to pervasive data access:– Varying I/O performance
– Energy hogs!
– Stale, inconsistent data
• BlueFS overcomes these barriers
The Blue File System 33
Change is ConstantChange is Constant• Access times vary across storage devices
• Wireless networks are highly variable
• Power management affects performance
• BlueFS provides an adaptive cache hierarchy
The Blue File System 44
Power to the PeoplePower to the People• Distributed file systems use power hungry devices
• Distributed file systems not designed for energy
• BlueFS “clean sheet design” for energy efficiency
The Blue File System 55
You You CanCan Take it with You Take it with You
• Want to leverage the benefits of portable storage
• Portable storage is not a mobile data panacea– Can be lost, stolen, damaged
– Sharing is hard
– More replication = higher chances of stale/inconsistent data
• BlueFS integrates portable storage into file system
The Blue File System 66
OrganizationOrganization• Motivation
• The Blue File System
• Evaluation
• Related Work
• Conclusion
The Blue File System 77
> /BlueFS/> /BlueFS/
The Blue File SystemThe Blue File System
BlueFS Server
Local disk
Local disk
Work Home
The Blue File System 88
To BlueFS Server
Unlink
1
Unlink
2
Create
1
Create
2
Mkdir
1
Mkdir
2
Write to ManyWrite to Many
• Asynchrony improves performance• Aggregating writes saves energy
VFS Ops
BlueFS
To microdrive
Write
2
Write
1
The Blue File System 99
Read From AnyRead From Any
• BlueFS monitors cost of reading data from each device• Pick device best performance, least energy
> cat /BlueFS/foo
BlueFS
BlueFS Server
Blk 2Blk 2
Blk 1Blk 1
Microdrive
The Blue File System 1010
Power ManagementPower Management
• BlueFS integrated with power management strategies• When a device transitions, BlueFS is notified
Self Tuning Power Management
BlueFS
Hints State Transitions
The Blue File System 1111
Hiding device transitionsHiding device transitions1) Network accesses
Disk
2) Ghost hints issued 3) Disk spins up
5) Network transitions to PSM
Network
4) Disk accesses begin
The Blue File System 1212
Cache ManagementCache Management• Storage devices treated as cache
• BlueFS decides which files to cache
• When a device fills up, LRU used to make space
• Affinity: file always on portable storage
The Blue File System 1313
Cache ConsistencyCache Consistency
> /BlueFS/> /BlueFS/
BlueFS Server
Local disk
Work Home
Local disk
The Blue File System 1414
Evaluation GoalsEvaluation Goals
– How does performance of BlueFS compare to other DFS?
– What benefit does an adaptive cache hierarchy provide?
– How well does BlueFS support portable storage?
– How much does BlueFS reduce client energy usage?
– How does BlueFS perform with heterogeneous storage?
The Blue File System 1515
Comparing BlueFS to other DFSComparing BlueFS to other DFS
• BlueFS 10x faster than NFS, 16% faster than Coda WD
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econ
ds)NFS
Coda
Coda WD
BlueFS
•Andrew benchmark: Untar, configure, make, delete Apache source
6000.0
The Blue File System 1616
Benefits of Adaptive Cache HierarchyBenefits of Adaptive Cache Hierarchy
0200400600800
100012001400
0 128 256 384 512File Size (KB)
Tim
e (
ms
)
BlueFS
Ext2
•BlueFS reads 4k files up to 60x faster than ext2
•Read various files with the disk in standby mode
The Blue File System 1717
Support for Portable StorageSupport for Portable Storage
• BlueFS 44% faster than Lookaside, up to 3x faster for high latency
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Coda Lookaside BlueFS
•Ran a file system trace as fast as possible using portable storage
The Blue File System 1818
Energy Efficient Data AccessEnergy Efficient Data Access
• Reduces interactive delay 76%, 55% less energy than Coda
•Ran first 10,000 ops of Purcell trace with half full cacheRan first 10,000 ops of Purcell trace with half full cache
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FS
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Coda
BlueFS
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Inte
rac
tiv
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The Blue File System 1919
Heterogeneous StorageHeterogeneous Storage
• With flash BlueFS reduces interactive delay 48%, 25% less energy
•Added 16 MB flash to BlueFS, ran Purcell with full local cache
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FS
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The Blue File System 2020
Related WorkRelated Work
• AFS [Howard et al] • Coda [Kistler et al] & lookaside caching [Tolia et al]• PersonalRAID [Sobti et al]• Segank [Sobti et al]• Cooperative I/O [Weissel et al]• LBFS [Muthitacharoen et al]
The Blue File System 2121
ConclusionsConclusions
• BlueFS enables ubiquitous data access by:– Adapting to device characteristics– Reducing mobile computer energy usage– Seamlessly integrating portable storage
• Source: http://notrump.eecs.umich.edu/group/group.html
The Blue File System 2222
System ArchitectureSystem Architecture
Applications
BlueFS KernelModule
Wolverine
Linux Kernel
Linux File Cache
USBStick
CardFlash
Micro-drive
Local Disk
To BlueFS Server
VFS Operations
Up-call
The Blue File System 2323
BFS KernelBFS Kernel• Intercepts Linux VFS calls
– Communicates with Wolverine through pseudo-device driver
• Caches and invalidates data & metadata in Linux file cache
• Operations redirected to Wolverine– Enables support for devices with different consistency
semantics
