• Save money on bandwidth by disabling reflective rpc queries in Linux CentOS RHEL Ubuntu Debian


    Even today we see a lot of servers that have different services and ports open for rpc and this creates not only potential inward vulnerabilities but perhaps more common, the abuse of your network resources in reflective rpc queries. To stop this problem, you should disable and remove all services relating to rpc or at least block all relevant ports for the service. Surprisingly, there are still some providers and OS installs in Linux that install these services and leave them........
  • apache2 httpd apache server will not start [pid 22449:tid 139972160445760] AH00052: child pid 23248 exit signal Aborted (6) solution Mint Debian Ubuntu Redhat


    If you get this error, it is often because you have configured Apache with modules that weren't actually installed. Eg. you try to load the PHPmodule but didn't actually install the apache2 php module, so the server can't start. In general, this error can often be caused by issues with problematic modules and/or Apache being configured for modules that have not actually be installed (eg. libapache2-mod-php) is missing. The above results in this less than obv........
  • MariaDB / MySQL Reset Root Forgotten Password on Centos 7


    mysql reset root password. Oops I can't remember my MySQL root password! [root@centos7test etc]# mysql -u root -p Enter password: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) First we need to stop mariadb: systemctl stop mariadb Now we need to restart it with skip-grant-tables whic........
  • MySQL Bash Query to pipe input directly without using heredoc trick


    Most of us know the heredoc method but what if you need a basic query done repeatedly and manually while working from bash? It is a pain to manually type mysql and login each time. With this command below you can semi-automate those queries: echo "use somedb; select * from auctions" | mysql -u root --password="yourpassword" Just modify the above to suit your needs and you can add more queries by adding a sem........
  • Bind / named not responding to queries solution


    By default bind will not respond to outside queries for security reasons. In most distributions you will find the default in /etc/named.conf looks like this at the top under options: listen-on port 53 { 127.0.0.1; }; listen-on-v6 port 53 { ::1; }; directory "/var/named";........
  • Cisco Unified Communications Manager / CUCM IP 8.6,10,12 Install Error Solution


    Install Errors on Version 12: This error happened on QEMU emulator version 2.11.1 pve-qemu-kvm_2.11.1-5 on Proxmox/Debian but installing on QEMU.12 on Centos 6 did not produce the error. *Update it is not related to the OS or QEMU version. This happened in Centos 6 too after a second install. What really causes this even though you successfully install........
  • MySQL Using mytop Debug Source of High IO and Slow Performance


    mytop is one of my favorite tools and it is fairly simple aside from a few caveats and issues that persist to this day. To install it on Centos: yum -y install centos Configure ~/.mytop vi ~/.mytop user=root host=localhost db=test #port=3306 socket=/var/lib/mysql/mysql.sock header=1 color=1 Try runni........
  • MySQL Cannot Update/Write to any database table solution


    This happened on Centos for no apparent reason with no obvious issue in the logs. Data could be read fine but not written (possibly due to some corruption or out of memory issue in the OpenVZ container is the best guess). All mysql update and insert queries failed freezing without any error log on any database and table. Tried to restart: service mysqld restart Timeout error occurred trying to stop MySQL........
  • Linux how to whois query other gTLDs such as .club solution


    whois in Linux is incredibly out of date and does not seem to recognize most new TLDs domains, but there is a quick and easy tip/hack/tweak for this. An example of new TLD's site as .review .site .club whois somesite.club No whois server is known for this kind of object. bash to the rescue Now I did try to apply this in .bashrc but DONOT! Ithink the * wil........
  • bind/named rndc: connect failed: 127.0.0.1#953: connection refused (solution)


    service named status rndc: connect failed: 127.0.0.1#953: connection refused named (pid 10557) is running... This issue is normally caused by a permissions issue where named doesn't have the permissions to read the rndc.key. Check /var/log/messages: Jan 4 17:06:22 storagebox named[10753]: none:0: open: /etc/rndc.key: permission denied Jan 4 17:06:22 storagebox named[10........
  • /usr/libexec/mysqld: The table 'session' is full solution


    First of all if you're getting this error it is a result of extreme database activity. If you aren't expecting it or it doesn't make sense to you 99% of the time this is a database driven script being exploited (some common examples I see often are things like phpBB being hit by dozens, hundreds or thousands of bots making constant DB write requests). The easiest way to identify this is to restart MySQL and then run the third party tool "mtop" and you'll see all........
  • mysql how to kill individual process/query


    Enter the console as root mysql -u root -p Then kill the process (where 1234 = the thread ID) kill 1234 It's also a good idea to use a tool like "mtop" to monitor which processes and queries are slow, killing them is a temporary fix while you try to isolate the actual problem.........
  • mysql enable slow query logging/Query Cache Solution - find/track cause of slow mysqld/high IO/CPU usage


    If you have a webserver and find you have high IO/lagginess MySQL is one of the first things to check. It turns out MySQL was my problem and it was creating a high load on my server, especially for IO. How to Enable MySQL Slow Query Logging To Find Slow Performance/Queries vi /etc/my.cnf Add this anywhere under [mysqld] #slow queries log-slow-queries = /var/log/mysql/mysqlslowqueries.log long_query_time = 1........
  • MySQL SubQuery


    MySQL SubQueryI was trying to do a sub-query here but it wouldn't work (Syntax Error) in MySQL for some reason even though based on the SQL standards it should be ok. [i:1268bfa39e][b:1268bfa39e]I found the reason this doesn't work. I am using MySQL 3.23 and I read on the MySQL web site that versions before 4.1 DO NOT SUPPORT SUB-QUERIES so it showed me how to rewrite the following as a LEFT join instead of a sub-query. [/b:1268bfa39e][/i:1268bfa39e]........
  • Latest Articles

  • Apache PHP sending expires header solution cannot use cache with CDN
  • How to install virt-manager in Mint 22/Ubuntu 22
  • Infiniband Guide
  • python mysql install error: /bin/sh: 1: mysql_config: not found /bin/sh: 1: mariadb_config: not found /bin/sh: 1: mysql_config: not found mysql_config --version
  • FreePBX 17 How To Add a Trunk
  • Docker Container Onboot Policy - How to make sure a container is always running
  • FreePBX 17 How To Add Phones / Extensions and Register
  • Warning: The driver descriptor says the physical block size is 2048 bytes, but Linux says it is 512 bytes. solution
  • Cisco How To Use a Third Party SIP Phone (eg. Avaya, 3CX)
  • Cisco Unified Communication Manager (CUCM) - How To Add Phones
  • pptp / pptpd not working in DD-WRT iptables / router
  • systemd-journald high memory usage solution
  • How to Install FreePBX 17 in Linux Debian Ubuntu Mint Guide
  • How To Install Cisco's CUCM (Cisco Unified Communication Manager) 12 Guide
  • Linux Ubuntu Redhat How To Extract Images from PDF
  • Linux and Windows Dual Boot Issue NIC Won't work After Booting Windows
  • Cisco CME How To Enable ACD hunt groups
  • How to install gns3 on Linux Ubuntu Mint
  • How to convert audio for Asterisk .wav format
  • Using Cisco CME Router with Asterisk as a dial-peer