Ajit / Inder, Please see http://wiki.apache.org/hadoop/FAQ#On_an_individual_data_node.2C_how_do_you_balance_the_blocks_on_the_disk.3F
On Tue, Nov 22, 2011 at 9:44 PM, Ajit Ratnaparkhi <ajit.ratnapar...@gmail.com> wrote: > Thanks for Help Joey! > Does just copying block files from one drive to another work? > Isn't there metadata maintained at datanode about block locations on that > datanode? If not, then how does datanode know about blocks stored on it? > > -Ajit. > On Tue, Nov 22, 2011 at 5:25 PM, Joey Echeverria <j...@cloudera.com> wrote: >> >> The balancer only balances between datanodes. This means the new >> drives won't get used until you start writing new data to them. If you >> want to balance the drives on a node, you need to >> >> 1) copy a bunch of block files from the old drives to the new drives >> 2) shutdown the datanode >> 3) delete the old block files >> 4) configure the datanode to see the new drives >> 5) start the datanode >> >> -Joey >> >> On Tue, Nov 22, 2011 at 6:43 AM, Ajit Ratnaparkhi >> <ajit.ratnapar...@gmail.com> wrote: >> > Hi, >> > If I add additional disks to existing datanode (assume existing datanode >> > has >> > 7 1TB disk which are already 80% full and then I add two new 2TB disks >> > 0% >> > full) and then run balancer, does balancer balance data in a datanode? >> > ie. >> > Will it move data from existing disks to newly added disks such that all >> > disks are approx equally full ? >> > thanks, >> > Ajit. >> >> >> >> -- >> Joseph Echeverria >> Cloudera, Inc. >> 443.305.9434 > > -- Harsh J
