Performance Tuning

System Performance Tuning : Memory

• Share Memory - 有些程式需要用到比較多 Share Memory (共享記憶體), 如: Kerrighed (2008-03-20 (rock/rider))

  echo "kernel.shmall = 796917578" >> /etc/sysctl.conf
  echo "kernel.shmmax = 796917578" >> /etc/sysctl.conf
  echo "kernel.shmmni = 4096"      >> /etc/sysctl.conf
  

System Performance Tuning : File System

• /etc/security/limits.conf - 每個程序(process)可以開啟檔案的個數(number limits of open files per process) - 像 HDFS 的 DataNode 就需要調整這種參數(2010-02-22)

  /etc/security/limits.conf

  @@ -49 +49 @@
   #ftp             -       chroot          /ftp
   #@student        -       maxlogins       4
   
  +*      soft        nofile        8192
  +
   # End of file

I/O Performance Tuning : NFS

• NFS Tuning - /etc/fstab - 加大 NFS read/write size 可以提升檔案系統的 I/O 效率 (2008-03-20 (rock/rider))

  192.168.0.111:/home /home nfs rw,bg,soft,intr,rsize=262144,wsize=262144 0 4
  192.168.0.111:/opt  /opt  nfs ro,bg,soft,intr,rsize=262144,wsize=262144 0 4
  192.168.0.111:/usr  /usr  nfs ro,bg,soft,intr,rsize=262144,wsize=262144 0 4
  

Network Performance Tuning

• TCP Tuning - (2008-03-20 (LSI))

  echo 262144               > /proc/sys/net/core/rmem_default
  echo 8388608              > /proc/sys/net/core/wmem_max
  echo 8388608              > /proc/sys/net/core/rmem_max
  echo "4096 87380 4194304" > /proc/sys/net/ipv4/tcp_rmem
  echo "4096 65536 4194304" > /proc/sys/net/ipv4/tcp_wmem
  

Power Management

• 啟動 SATA ALPM 電源管理功能 - ​powertop 提供之建議

  echo min_power > /sys/class/scsi_host/host0/link_power_management_policy