Date post: | 20-Nov-2015 |
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Elastic Quota File System (EQFS)
AmitGudNileshChoudhary
DepartmentofComputerD.Y.PatilCollegeofEngg.
Introduction TypicalNetworkScenario
Differenttypesofuserswithdifferentneeds
Variablequotausage
Notpracticaltosetdifferentquotalimitsforlargenumberofusers
Lossofuserspaceifusersdonotusethequotaallocatedtothemeffectively
Noflexibilty
Some Statistics
At95%ofthetimesalltheusersdon'tuse100%oftheirquota
47%oftheusersuse60%oftheirquota
22%oftheusersuselessthan15%oftheirquota
Source:basedonastudyresultsbyBCCInc.onpopularemailservices
What is EQFS? EQFSisElasticQuotaFileSystem
EQFS:
Providescontrolledflexibilityforuserstoeffectiveyusemorethantheallocatedquota
Handlesvariablequotausage Eliminatestheneedtoassigndifferentquotalimitsforusers
withvariableneeds Providesdisklimitsforanetworkirrespectiveofanyuser
quota Postponesdeletionoffilesoncrossingthequotalimit Extendsthequotalimitonrequirementbyallocatingfree
unuseduserspace
How it works?
User2User1
2
10
User2
User1Free8
How it works? Contd...
User2User1
2
10
Elastic User1
User2User1
3
Free
3
10
How it works?
User2User1
10
Elastic
User1
3
User210 Free
User3
User1
What is EQFS? EQFSisElasticQuotaFileSystem
EQFS:
Providescontrolledflexibilityforuserstoeffectiveyusemorethantheallocatedquota
Handlesvariablequotausage Eliminatestheneedtoassigndifferentquotalimitsforusers
withvariableneeds Providesdisklimitsforanetworkirrespectiveofanyuser
quota Postponesdeletionoffilesoncrossingthequotalimit Extendsthequotalimitonrequirementbyallocatingfree
unuseduserspace
EQFS Operation Elasticfiles Whentomakefileselastic
Whenquotaisfullandyouneedadditionalspace
Whathappenswhenafileismadeelastic Owner'squotaisincreasedbyamountofthatfile'ssize
Thatelasticfilebelongstothesameowner
Theadditionalspaceistakenfromothersunusedspace(0.95)
Whichfilestomakeelastic Fileswithlessimportance Temporaryfiles
Riskinvolved Whenthethresholds(user,disk,group)arereached,theelasticfiles
areacteduponasperthepolicyset(0.05)
Where is EQFS?
EQFSisathinfilesystemlayeraboveVFS
Kernel
EQFS
VFS
UnderlyingFileSystem
EQFS Architecture
Kernelmodule
CharDevice
Mel
RelVFS
EQFSDaemon
DB(GDBM)
KernelSpace UserSpace
Thresholds
EQFSworksaround3Thresholds
UserThreshold
DiskThreshold
GroupThreshold
Thresholds contd...
GrouptempGroupStaff
GroupStudent
USERS
Groupswithsingleuser
Userthreshold
Groupthresholds
EQFS Commands
EQFSprovidesfollowingcommandsfortheuser
Melmakeelasticsyntax:#mel[parameter]filename:pathtothefileoperation:actiontobetakenonthefileparameter:destinationincaseofmove&compress
Relremoveelasticsyntax:#rel
SelShowelasticsyntax:#sel
Benchmarks (using Caldera AIM Independent Resource Suite IX) WithoutEQFS
CPU(thousandopspersecond)
Add Div MultShort 2354400 29160 346830Int 2215568 30119 394525Long 2271768 30708 375312Float 766800129000 432000Double 766800125400 461077
Disk/FileSystem/IO(persecond)
Dirsearches 34950 Copy 56945 KbSeqRead 247048 KbCreate/Close 142300 filesLink/Unlink 54085 pairsDirectoryoperqtions2543912
Benchmarks (using Caldera AIM Independent Resource Suite IX) WithEQFS
CPU(thousandopspersecond)
Add Div MultShort 2354308 29605 346826Int 2215448 30106 394522Long 2271429 30746 375309Float 766670128920 431969Double 766650125379 461075
Disk/FileSystem/IO(persecond)
Dirsearches 34946 Copy 56940 KbSeqRead 247044 KbCreate/Close 142229 filesLink/Unlink 54064 pairsDirectoryoperqtions2543900
Advantages EQFSmaximisestheserverspaceutilization
fortheusers
EQFSmeetsthevariablequotaneeds
Transparentreclaimingmechanism
Avoidtheindividualallocationofquotaforuserswithdifferentneeds,whichisnotpracticalwherethenumberofusersarelarge
Handlesthegroupquotasandkeepstheoverallusagewithincheckwithoutinternalinterference
Postponesthedeletionoffilesunlessthethresholdisreached
Advantages contd...
EQFSis
Independentoftheunderlyingfilesystem
Workswiththestandardquotasystem(libquota,edquota)
LowCPUusage
Transparenttotheuser
Thank You!
FurtherInfo:eqfs.sourceforge.net
Questions