Information Technology Reference
In-Depth Information
attributestreams-->storemetadatainMFTrecord;butalsostore
contentsoffilewithsmalldata
--extensible--canaddnewmetadatato
file
-->unlikeFFSinode(fixedstructure)
MFTrecordhasextensible/variablestructure
firstrecord:attributelist-->can
parsefile
[attributename->MFTrecordin
whichattributeislocated(formulti-MFTfiles)
--supportsmulti-forkfile(NTFScalls
thisX)
--residentandnonresidentattributes
--example:smallfile:resident
--med-largefile--1level
--hugefile--2level
...
freespace:bitmapfile
localityheuristics:???
13.2.4
Write anywhere file systems
basicidea:indexstructures-->fileblockscanbestored
anywhere
-->whenblockisupdated,don'tneedtoseekand
overwriteinplace;insteadcanwriteblock
onanyfreeblockneardiskhead.
WAFLdoesthisandgoesonebetter;notonlyarefile
blocksmobile,soareessentiallyallofthemetadata
(indexblocks,
whyisthisgood?goals/motivation:
