Thanks Harsh! On Tue, Nov 22, 2011 at 10:05 PM, Harsh J <ha...@cloudera.com> wrote:
> 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 >
