sysctl and you

If you have a Gig connection on your Linux server, your O/S might be robbing you of power. Try this out to start with, if it doesn’t work, reboot and your server will default back to their original settings sysctl -w net.core.rmem_max=8388608sysctl -w net.core.wmem_max=8388608sysctl -w net.core.rmem_default=65536sysctl -w net.core.wmem_default=65536sysctl -w net.ipv4.tcp_rmem=’4096 87380 8388608′sysctl -w net.ipv4.tcp_wmem=’4096 65536 […]

Technical Services

Do you have a project or need assistance in installing a content management system for your server? Do you need someone to maintain your server on a periodic basis. Well, I offers many different technical services. Why not contact me for a free quote? What I offer Services Include: WordPress installation and management (security updates) […]

More techie

Sorry, it’s been a while since I posted. I’ll be updating the site with more techie related stuff as I re-organize my tech notes once more.

Technical Services

Do you need help installing WordPress or managing it? Do you need assistance with administering your webserver? Do you need help overall with web-hosting? I have created a new part of my old venture: https://www.webpods.com/services andhttps://www.webpods.com/home

Wuhan Virus

There is a site that is putting together the real information on this virus, including what to be prepared for and what type of items you should carry in a prep kit, its an open community forum, so anyone can join and ask questions. https://www.ourpreps.com/community-forums/?fbclid=IwAR3-JVZE4QOHI-j7V-MVp7-1m-T9nc672MAZXZ6m6rhutFsfwEU52bLuAp8

Help fund

As time goes on, life can be a little hectic. I am currently facing a bit of a financial crisis and ask that if anyone has any projects they need done on the side to let me know. You can e-mail me robert@robertsarea.com As always, any donations are helpful as I go through this rougher […]

THP (Transparent Huge Pages)

According to RedHathttps://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/performance_tuning_guide/s-memory-transhuge I usually use THP and this can be enabled very easily within the running system by issuing echo always > /sys/kernel/mm/transparent_hugepage/enabledecho always > /sys/kernel/mm/transparent_hugepage/defrag With the above I always set the nr_hugepages to 512 or for smaller systems 128. echo 512 > /proc/sys/vm/nr_hugepages

Kernel params used for synfloods

echo 1 > /proc/sys/net/ipv4/tcp_syncookies echo 45 > /proc/sys/net/netfilter/nf_conntrack_tcp_timeout_syn_recv echo 3 > /proc/sys/net/ipv4/tcp_synack_retries echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle I tried to use these common values to help deter a syn flood from occurring. Syn-cookies challenges the other opponent. While you change the default timing of syn_recv from 60 seconds to 45 seconds which […]

Getting tired of a Synflood?

This dirty last ditch modification to the kernel will force close connections after so many seconds. The default is 60. echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout This will tell everyone that you have 30 seconds to finish or else I will drop your connection. This is good in a pinch, but do not recommend running this at […]