Database Reference
In-Depth Information
◦
[-restoreFailedStorage true|false|check]
: This enables
to set/unset or check to attempt to restore failed storage replicas.
◦
[-refreshNodes]
: This updates the namenode daemon with the set
of datanodes allowed to connect to the namenode daemon.
◦
[-setQuota <quota> <dirname>...<dirname>]
: This sets
the quota (the number of items) for the directory/directories.
◦
[-clrQuota <dirname>...<dirname>]
: This clears the set
quota for the directory/directories.
◦
[-setSpaceQuota <quota> <dirname>...<dirname>]
:
This sets the disk space quota for the directory/directories.
◦
[-clrSpaceQuota <dirname>...<dirname>]
: This clears the
disk space quota for the directory/directories.
◦
[-refreshserviceacl]
: This refreshes the service-level authoriza-
tion policy file. We will be learning more about authorization later.
◦
[-printTopology]
: This prints the tree of the racks and their nodes
as reported by the namenode daemon.
◦
[-refreshNamenodes datanodehost:port]
: This reloads the
configuration files for a datanode daemon, stops serving the removed
block pools, and starts serving new block pools. A block pool is a set of
blocks that belong to a single namespace. We will be looking into this
concept a bit later.
◦
[-deleteBlockPool datanodehost:port blockpoolId
[force]]
: This deletes a block pool of a datanode daemon.
◦
[-setBalancerBandwidth <bandwidth>]
: This sets the band-
width limit to be used by the balancer. The bandwidth is the value in
bytes per second that the balancer should use for data blocks movement.
◦
[-fetchImage <local directory>]
: This gets the latest
fsimage
file from namenode and saves it to the specified local direct-
ory.
◦
[-help [cmd]]
: This displays help for the given command or all
commands if a command is not specified.