If you can benchmark before and after, please post the results when you are done!
Things like your index's size, and the amount of RAM in your computer will help make it meaningful. If all of your index can be cached, I don't think fragmentation is going matter much, once you get warmed up. Tom On Wed, Dec 8, 2010 at 9:59 AM, Will Milspec <will.mils...@gmail.com> wrote: > Hi all, > > Pardon if this isn't the best place to post this email...maybe it belongs on > the lucene-user list . Also, it's basically windows-specific,so not of use > to everyone... > > The question: does NTFS fragmentation affect search performance "a little > bit" or "a lot"? It's obvious that "fragmentation will slow things down", > but is it a factor of .1, 10 , or 100? (i.e what order of magnitude)? > > As a follow up: should solr/lucene users periodically remind Windows > sysadmins to defrag their drives ? > > On a production system, I ran the windows defrag "analyzer" and found heavy > fragmentation on the lucene index. > > 11,839 492 MB \data\index\search\_6io5.cfs > 7,153 433 MB \data\index\search\_5ld6.cfs > 6,953 661 MB \data\index\search\_8jvj.cfs > 5,824 74 MB \data\index\search\_5ld7.frq > 5,691 356 MB \data\index\search\_9eev.fdt > 5,638 352 MB \data\index\search\_8mqi.fdt > 5,629 352 MB \data\index\search\_8jvj.fdt > 5,609 351 MB \data\index\search\_88z8.fdt > 5,590 355 MB \data\index\search\_96l5.fdt > 5,568 354 MB \data\index\search\_8zjn.fdt > 5,471 342 MB \data\index\search\_5wgo.fdt > 5,466 342 MB \data\index\search\_5uo1.fdt > 5,450 340 MB \data\index\search\_5hrn.fdt > 5,429 345 MB \data\index\search\_6nyy.fdt > 5,371 353 MB \data\index\search\_8sob.fdt > > Incidentally, we periodically experience some *very* slow searches. Out of > curiousity, I checked for file fragmentation (using 'analyze' mode of the > nfts defragger) > > nota bene: Windows sysinternals has a utility "Contig.exe" whic allows you > to defragment individual drives/directories. We'll use that to defragmeent > the index direcotires > > will >
