Tuning for SSDs

On servers with SSDs:

  1. Enable TRIM operation in the mfs.conf file, if recommended by the SSD vendor.
    By default, TRIM is disabled. To enable, set the value for mfs.ssd.trim.enabled to 1 in the mfs.conf file. For example:
    mfs.ssd.trim.enabled=1
  2. Disable IO throttling in the mfs.conf file.
    To disable, set the value for mfs.disk.iothrottle.count to 50000. The default value for mfs.disk.iothrottle.count is 100. For example:
    mfs.disk.iothrottle.count=50000
  3. Create storage pool with multiple SSDs (so that the throughput is less than 2GB/sec).
    Note: Create one storage pool per SSD only if the device is high-end.
    To create, run disksetup:
    /opt/mapr/server/disksetup -W <n> disks.txt
    For example, to create a storage pool with 2 SSDs, run the following command:
    /opt/mapr/server/disksetup -W 2 disks.txt
    For more information, see disksetup.
  4. Enable noop scheduler on the SSD, if it is already not enabled, by running this command:
    echo "noop"> /sys/block/sda/queue/scheduler