Setting Readahead for MongoDB volume

Issue

• We are receiving warning in MongoDB related to Readahead of the MongoDB volume

  WARNING: Readahead for /var/lib/mongodb/data is set to 4096KB",
  We suggest setting it to 256KB (512 sectors) or less",
  

• The readhead setting was adjusted by using the command:

  blockdev --setra 256 /dev/mapper/vg_os-mongodb
  

• How can this setting be made persistent?