In theory the block allocation strategy is round robin amount the set of storage locations that meet the minimum free space requirements.
On Thu, Apr 23, 2009 at 12:55 PM, Bhupesh Bansal <[email protected]>wrote: > What configuration are you using for the disks ?? > > Best configuration is just doing a JBOD. > > http://www.nabble.com/RAID-vs.-JBOD-td21404366.html > > Best > Bhupesh > > > > On 4/23/09 12:54 PM, "Mike Andrews" <[email protected]> wrote: > > > i have a bunch of datanodes with several disks each, and i noticed > > that sometimes dfs blocks don't get evenly distributed among them. for > > instance, one of my machines has 5 disks with 500 gb each, and 1 disk > > with 2 TB (6 total disks). the 5 smaller disks are each 98% full, > > whereas the larger one is only 12% full. it seems as though dfs should > > do better by putting more of the blocks on the larger disk first. and > > mapreduce jobs are failing on this machine with error > > "java.io.IOException: No space left on device". > > > > any thoughts or suggestions? thanks in advance. > > -- Alpha Chapters of my book on Hadoop are available http://www.apress.com/book/view/9781430219422
