anchor.diff:  
   ----
   mvn test -PrunAllTests -Dtest.build.data.basedirectory=/ram2G
  -----
  -
  -On earlier versions, use:
  -
  -----
  -mvn test -P runAllTests -Dtest.build.data.basedirectory=/ram2G
   ----
   
   [[hbase.unittests.cmds.test.hbasetests]]
  
positive.code: reliably with perhaps an unlucky sporadic flakey test failure. On other branches, the case may be less so with
  frequent flakies and even broken tests in need of attention that fail 100% of the time. Try and figure
  the state of tests on the branch you are currently interested in; the current state of nightly
  linke:https://builds.apache.org/view/H-L/view/HBase/job/HBase%20Nightly/[apache jenkins builds] is a good
  place to start. Tests on master branch are generally not in the best of condition as releases
  are less frequent off master. This can make it hard landing patches especially given our dictum that
  patches land on master branch first.
  
  The full test suite can take from 5-6 hours on an anemic VM with 4 CPUs and minimal
  parallelism to 50 minutes or less on a linux machine with dozens of CPUs.
  
  When you go to run the full test suite, make sure you up the test runner user nproc
  (`ulimit -u` -- make sure it > ~6000 or more even) and the number of files (`ulimit -n` -- make
  sure it > 10240 or so) limits on your system. Errors because the test run hits
  limits are often only opaquely related to the constraint. You can see the current
  user settings by running `ulimit -a`.
  
  
negative.code: ----
  
  If a 32 core machine, you should see periods during which 32 forked jvms appear in your process listing each running unit tests.
  Your milage may vary. Dependent on hardware, overcommittment of CPU and/or memory can bring the test suite crashing down,
  usually complaining with a spew of test system exits and incomplete test report xml files. Start gently, with the default fork
  and move up gradually.
  
  Adding the `--threads=N`, maven will run N maven modules in parallel (when module inter-dependencies allow). Be aware, if you have
  set the forkcount to `1.0C`, and the `--threads` count to '2', the number of concurrent test runners can approach
  2 * CPU, a count likely to overcommit the host machine (with attendant test exits failures).
  
  You will need ~2.2GB of memory per forked JVM plus the memory used by maven itself (3-4G).
  
  ===== RAM Disk
  
  To increase the speed, you can as well use a ramdisk. 2-3G should be sufficient. Be sure to
  delete the files between each test run. The typical way to configure a ramdisk on Linux is:
  