By default, the perfSONAR Toolkit installation follows the advice of ESnet’s “fasterdata” knowledge base for test and measurement hosts:
These tuning settings should be fine for most uses of perfSONAR, but there are a couple of cases where you might want to adjust these.
- 40G hosts (or even 2x10G bonded hosts)
- hosts where much of your testing is over paths with more than 100ms RTT
For such cases, you may want to increase the max buffer settings in /etc/sysctl.conf, for example:
#allow hand tuning up to 256MB buffers net.core.rmem_max = 268435456 net.core.wmem_max = 268435456 # allow auto-tuning up to 128MB buffers net.ipv4.tcp_rmem = 4096 87380 134217728 net.ipv4.tcp_wmem = 4096 65536 134217728
Note that any time you upgrade the perfSONAR Toolkit, you should make sure your modified settings are still in place.