Many thanks. We use xfs all the time.Have you try the ext4 filesystem?
2011/5/6 Ferdy Galema <ferdy.gal...@kalooga.com> > Hi, > > We've performed tests for ext3 and xfs filesystems using different > settings. The results might be useful for anyone else. > > The datanode cluster consists of 15 slave nodes, each equipped with 1Gbit > ethernet, X3220@2.40GHz quadcores and 4x1TB disks. The disk read speeds > vary from about 90 to 130MB/s. (Tested using hdparm -t). > > Hadoop: Cloudera CDH3u0 (4 concurrent mappers / node) > OS: Linux version 2.6.18-238.5.1.el5 (mockbu...@builder10.centos.org) (gcc > version 4.1.2 20080704 (Red Hat 4.1.2-50)) > > #our command > for i in `seq 1 10`; do ./hadoop jar ../hadoop-examples-0.20.2-cdh3u0.jar > randomwriter -Ddfs.replication=1 /rand$i && ./hadoop fs -rmr /rand$i/_logs > /rand$i/_SUCCESS && ./hadoop distcp -Ddfs.replication=1 /rand$i > /rand-copy$i; done > > Our benchmark consists of a standard random-writer job followed by a distcp > of the same data, both using a replication of 1. This is to make sure only > the disks get hit. Each benchmark is ran several times for every > configuration. Because of the occasional hickup, I will list both the > average and the fastest times for each configuration. I read the execution > times off the jobtracker. > > The configurations (with exection times in seconds of Avg-writer / > Min-writer / Avg-distcp / Min-distcp) > ext3-default 158 / 136 / 411 / 343 > ext3-tuned 159 / 132 / 330 / 297 > ra1024 ext3-tuned 159 / 132 / 292 / 264 > ra1024 xfs-tuned 128 / 122 / 220 / 202 > > To explain, ext3-tuned is with tuned mount options > [noatime,nodiratime,data=writeback,rw] and ra1024 means a read-ahead buffer > of 1024 blocks. The xfs disks are created using mkfs options > [size=128m,lazy-count=1] and mount options [noatime,nodiratime,logbufs=8]. > > In conclusion it seems that using tuned xfs filesystems combined with > increased read-ahead buffers increased our basic hdfs performance with about > 10% (random-writer) to 40% (distcp). > > Hopefully this is useful to anyone. Although I won't be performing more > tests soon I'd be happy to provide more details. > Ferdy. > -- 阿昌
