Energy Efficiency and Storage Flexibility in the Blue File SystemTowards Ubiquitous Data AccessChange is ConstantPower to the PeopleYou Can Take it with YouSlide 6The Blue File SystemWrite to ManyRead From AnyPower ManagementHiding device transitionsCache ManagementCache ConsistencyEvaluation GoalsComparing BlueFS to other DFSBenefits of Adaptive Cache HierarchySupport for Portable StorageEnergy Efficient Data AccessHeterogeneous StorageRelated WorkConclusionsSystem ArchitectureBFS KernelEnergy Efficiency and Storage Energy Efficiency and Storage Flexibility in the Blue File SystemFlexibility in the Blue File SystemEdmund B NightingaleJason FlinnUniversity of MichiganThe Blue File System22Towards Ubiquitous Data AccessTowards Ubiquitous Data Access•Pervasive computing: anywhere anytime any device–Ubiquitous WiFi access–Mobile storageBarriers to pervasive data access:–Varying I/O performance–Energy hogs!–Stale, inconsistent data•BlueFS overcomes these barriersThe Blue File System33Change is ConstantChange is Constant•Access times vary across storage devices•Wireless networks are highly variable •Power management affects performance•BlueFS provides an adaptive cache hierarchyThe Blue File System44Power 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 efficiencyThe Blue File System55You 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 systemThe Blue File System66OrganizationOrganization•Motivation•The Blue File System•Evaluation•Related Work•ConclusionThe Blue File System77> /BlueFS/> /BlueFS/The Blue File SystemThe Blue File SystemBlueFS ServerLocal diskLocal diskWorkHomeThe Blue File System88To BlueFS ServerUnlink1Unlink2Create1Create2Mkdir1Mkdir2Write to ManyWrite to Many•Asynchrony improves performance•Aggregating writes saves energyVFS OpsBlueFSTo microdriveWrite2Write1The Blue File System99Read From AnyRead From Any•BlueFS monitors cost of reading data from each device•Pick device best performance, least energy> cat /BlueFS/fooBlueFSBlueFS ServerBlk 2Blk 2Blk 1Blk 1MicrodriveThe Blue File System1010Power ManagementPower Management•BlueFS integrated with power management strategies•When a device transitions, BlueFS is notifiedSelf Tuning Power ManagementBlueFSHints State TransitionsThe Blue File System1111Hiding device transitionsHiding device transitions1) Network accessesDisk2) Ghost hints issued 3) Disk spins up5) Network transitions to PSMNetwork4) Disk accesses beginThe Blue File System1212Cache 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 storageThe Blue File System1313Cache ConsistencyCache Consistency> /BlueFS/> /BlueFS/BlueFS ServerLocal diskWorkHomeLocal diskThe Blue File System1414Evaluation 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 System1515Comparing BlueFS to other DFSComparing BlueFS to other DFS•BlueFS 10x faster than NFS, 16% faster than Coda WD•Andrew benchmark: Untar, configure, make, delete Apache source6000.0The Blue File System1616Benefits of Adaptive Cache HierarchyBenefits of Adaptive Cache Hierarchy•BlueFS reads 4k files up to 60x faster than ext2•Read various files with the disk in standby modeThe Blue File System1717Support for Portable StorageSupport for Portable Storage•BlueFS 44% faster than Lookaside, up to 3x faster for high latency•Ran a file system trace as fast as possible using portable storageThe Blue File System1818Energy 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 cacheThe Blue File System1919Heterogeneous StorageHeterogeneous Storage•With flash BlueFS reduces interactive delay 48%, 25% less energy•Added 16 MB flash to BlueFS, ran Purcell with full local cacheThe Blue File System2020Related 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 System2121ConclusionsConclusions•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.htmlThe Blue File System2222System ArchitectureSystem Architecture ApplicationsBlueFS KernelModuleWolverineLinux KernelLinux File CacheUSBStickCardFlashMicro-driveLocal DiskTo BlueFS ServerVFS Operations Up-callThe Blue File System2323BFS 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