
Category Archives: Linux
wp_wfConfig too large
While debugging some bottlenecks in one of my servers…

i’v realised that one of my db queries to Wordfence tables were causing it.


Solution was to… uninstall wordfence – to clean all their tables – anda reinstall it.
After removing it 23:30, CPU usage and Load Average was a significantly reduced.



SELinux – Failed to open stream: Permission denied
sudo chcon -t httpd_sys_rw_content_t {path_of_your_project_directory} -R
explainshell.com
write down a command-line to see the help text that matches each argument
Hello,
This site contains 29761 parsed manpages from sections 1 and 8 found in Ubuntu’s manpage repository. A lot of heuristics were used to extract the arguments of each program, and there are errors here and there, especially in manpages that have a non-standard layout.
It is written in Python and uses bashlex, a bit of NLTK (to find the interesting parts of the manpage), a little d3.js (for the connecting lines graphic) and Flask. It is served with uwsgi and nginx. Source code is available on github.
My name is Idan Kamara and you can contact me at idan at explainshell dot com for any questions or suggestions.
VirtualBox – Share internet to (linux) VM – MACOSX!
On your CentOS edit /etc/sysconfig/network-scripts/ifcfg-enp0s3 and set ONBOOT to yes and add the DNSs… in this case I’m using Google DNS ips.
ONBOOT=yes DNS1=8.8.8.8 DNS2=8.8.4.4
Should work! 😉
google pagespeed – centos installation
Let’s edit/create google-mod-pagespeed.repo
vi /etc/yum.repos.d/google-mod-pagespeed.repo
and add
[google–mod–pagespeed]name=google–mod–pagespeedbaseurl=http://dl.google.com/linux/mod-pagespeed/rpm/stable/$basearchenabled=1gpgcheck=0
yum install mod-pagespeed
service httpd restart
This is how we test it…
curl -D- http://localhost/ | head -10
[root@sd-hooray webroot]# curl -D- http://localhost/ | head -10
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 4328 100 4328 0 0 27929 0 –:–:– –:–:– –:–:– 28103
HTTP/1.1 200 OK
Date: Wed, 12 Sep 2018 15:52:41 GMT
Server: Apache/2.4.6 (CentOS) PHP/5.6.38
X-Powered-By: PHP/5.6.38
X-Mod-Pagespeed: 1.13.35.2-0
Vary: Accept-Encoding
Cache-Control: max-age=0, no-cache, s-maxage=10
Content-Length: 4328
Content-Type: text/html; charset=iso-8859-1
PEAR – DB Error: extension not found
Yesterday I had to set up a new server for bunch of sites from 2008 using PHP Pear….
DB Error: extension not found
You might need to add the following line at the end of /etc/php.ini
extension=mysqli.so
fail2ban.actions [14644]: NOTICE [sshd] 113.131.58.142 already banned
Meanwhile in a new VPS…
2018-04-18 19:56:42,211 fail2ban.actions [14644]: NOTICE [sshd] 113.131.58.142 already banned 2018-04-18 19:56:43,213 fail2ban.actions [14644]: NOTICE [sshd] 113.131.58.142 already banned 2018-04-18 19:56:44,214 fail2ban.actions [14644]: NOTICE [sshd] 113.131.58.142 already banned 2018-04-18 19:56:45,215 fail2ban.actions [14644]: NOTICE [sshd] 113.131.58.142 already banned 2018-04-18 19:56:46,217 fail2ban.actions [14644]: NOTICE [sshd] 113.131.58.142 already banned 2018-04-18 19:56:47,218 fail2ban.actions [14644]: NOTICE [sshd] 195.72.223.106 already banned 2018-04-18 19:56:48,219 fail2ban.actions [14644]: NOTICE [sshd] 195.72.223.106 already banned
YAH!
Take a look at /etc/fail2ban/jail.local or /etc/fail2ban/jail.d/00-firewalld.conf
banaction = firewallcmd-ipset
or
banaction = iptables-multiport
fail2ban – remove ip from ban
https://serverfault.com/a/760324/152273
please give some votes up to the author! 😉
see also http://www.digitalwhores.net/linux/iptables-unban-ip/
Meltdown & Spectre – CentOS
This is, for what I’v read about, the two main things that we need to have updated…
kernel-3.10.0-693.11.6.el7.x86_64
microcode_ctl-2.1-22.2.el7.x86_64
Check them trought uname -r and dmesg | grep microcode
[root@sd-56969 www]# systemctl status microcode -l ● microcode.service - Load CPU microcode update Loaded: loaded (/usr/lib/systemd/system/microcode.service; enabled; vendor preset: enabled) Active: inactive (dead) since Fri 2018-01-05 17:43:08 CET; 1 weeks 6 days ago Process: 692 ExecStart=/usr/bin/bash -c grep -l GenuineIntel /proc/cpuinfo | xargs grep -l -E "model[[:space:]]*: 79$" > /dev/null || echo 1 > /sys/devices/system/cpu/microcode/reload (code=exited, status=0/SUCCESS) Main PID: 692 (code=exited, status=0/SUCCESS) Jan 05 17:43:08 sd-56969 systemd[1]: Starting Load CPU microcode update... Jan 05 17:43:08 sd-56969 systemd[1]: Started Load CPU microcode update.