title: Why redis can not set maximum open file
body: <pre>
  1167:M 26 Apr 13:00:34.666 # You requested maxclients of 10000 requiring at least 10032 max file descriptors.
  1167:M 26 Apr 13:00:34.667 # Redis can't set maximum open files to 10032 because of OS error: Operation not permitted.
  1167:M 26 Apr 13:00:34.667 # Current maximum open files is 4096. maxclients has been reduced to 4064 to compensate for low ulimit. If you need higher maxclients increase 'ulimit -n'.
  1167:M 26 Apr 13:00:34.685 # Creating Server TCP listening socket 192.34.62.56​​:6379: Name or service not known
  1135:M 26 Apr 20:34:24.308 # You requested maxclients of 10000 requiring at least 10032 max file descriptors.
  1135:M 26 Apr 20:34:24.309 # Redis can't set maximum open files to 10032 because of OS error: Operation not permitted.
  1135:M 26 Apr 20:34:24.309 # Current maximum open files is 4096. maxclients has been reduced to 4064 to compensate for low ulimit. If you need higher maxclients increase 'ulimit -n'.
  1135:M 26 Apr 20:34:24.330 # Creating Server TCP listening socket 192.34.62.56​​:6379: Name or service not known
  </pre>