...
| Warning |
|---|
| It is highly important that on the Appliance OS installation phase the system will have all necessary resources allocated, especially the memory allocation. If You are installing Non-Appliance installation, a report listing system tests and gaps will be generated, please review the “kernel parameters” section and adjust you system to the recommended values, especially the performance related settings. This task is usually done by the Linux system administrator. |
The following section details the most significant DPOD system settings:
Some of the parameters are based on the following calculations:
...
- vm_dirty_bg_ratio=3
- vm_dirty_ratio=5
...
Performance related settings
...
vm.dirty_ratio = $vm_dirty_ratio
...
- Network tuning
# Basic TCP tuning
...
net.ipv4.tcp_syn_retries = 3
...
# Enable a fix for RFC1337 - time-wait assassination hazards in TCP
net.ipv4.tcp_rfc1337 = 1
...
# Minimum interval between garbage collection passes This interval is
...
net.ipv4.inet_peer_gc_mintime = 5
...
# Enable window scaling as defined in RFC1323
...
# Enable select acknowledgments
net.ipv4.tcp_sack = 1
# Enable FACK congestion avoidance and fast retransmission
net.ipv4.tcp_fack = 1
...
# Allows TCP to send "duplicate" SACKs
net.ipv4.tcp_dsack = 1
...
# Enable fast recycling TIME-WAIT sockets
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_max_syn_backlog = 20000
...
# tells the kernel how many TCP sockets that are not attached
...
net.ipv4.tcp_max_orphans = $max_orphan
...
# maximum number of sockets in TIME-WAIT to be held simultaneously
net.ipv4.tcp_max_tw_buckets = $max_tw
...
# don't cache ssthresh from previous connection
...
net.ipv4.tcp_moderate_rcvbuf = 1
# increase Linux autotuning TCP buffer limits
...
net.ipv4.tcp_wmem = 4096 65536 33554432
...
# increase TCP max buffer (bytes)
...
net.core.wmem_max = 67108864
...
net.core.netdev_max_backlog = 30000
net.core.somaxconn = 65000
Resources related settings
...
vm.min_free_kbytes = $min_free
...
# system open file limit
fs.file-max = $file_max
...
# Maximum shared segment size in bytes
kernel.shmmax = $shmmax
...
# Maximum number of shared memory segments in pages
kernel.shmall = $shmall
Security related settings
...
net.ipv4.tcp_syncookies = 1
...
General settings
# Defines the local port range that is used by TCP and UDP
net.ipv4.ip_local_port_range = 1024 65535
...
59999
# Enable timestamps (RFC1323)
...