Category: Linux

  • ISPmanager

    ISPmanager

    ISPmanager is a hosting control panel. The price starts at $5 per month for the lite version.

    To install ISPmanager, run

    wget http://download.ispsystem.com/install.sh
sh install.sh ISPmanager
  • APCu

    APCu

    APCu is an in-memory key-value store for PHP. Keys are of type string and values can be any PHP variables.

    APCu only supports userland caching of variables. APCu is APC stripped of opcode caching.

    https://github.com/krakjoe/apcu/

    Install PHP APC Cache on CentOS 7 using yum

  • apt force IPv4

    One of my internet provider only provide IPv4 connection. When i run apt install command, it failed with error as it try to connect using IPv6.

    boby@sok-01:~$ sudo apt install php7.3-curl
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:
  php7.3-curl
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 29.6 kB of archives.
After this operation, 123 kB of additional disk space will be used.
Err:1 http://ppa.launchpad.net/ondrej/php/ubuntu bionic/main amd64 php7.3-curl amd64 7.3.13-1+ubuntu18.04.1+deb.sury.org+1
  Could not connect to ppa.launchpad.net:80 (2001:67c:1560:8008::15). - connect (101: Network is unreachable) Could not connect to ppa.launchpad.net:80 (91.189.95.83), connection timed out
E: Failed to fetch http://ppa.launchpad.net/ondrej/php/ubuntu/pool/main/p/php7.3/php7.3-curl_7.3.13-1+ubuntu18.04.1+deb.sury.org+1_amd64.deb  Could not connect to ppa.launchpad.net:80 (2001:67c:1560:8008::15). - connect (101: Network is unreachable) Could not connect to ppa.launchpad.net:80 (91.189.95.83), connection timed out
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
boby@sok-01:~$

    To force apt to use IPv4 only, edit

    sudo vi /etc/apt/apt.conf.d/99-force-ipv4

    Add

    Acquire::ForceIPv4 "true";

    If you want to force IPv6, add

    Acquire::ForceIPv6 "true";

  • Set tab width in vim

    To set tab width in Vim, run

    :set tabstop=4

    To make it permanent, edit ~/.vimrc and add

    set tabstop=4

    back to vim

  • CentOS 7 resolv.conf make changes permanent

    On rebooting the CentOS 7 server, changes made to resolv.conf is lost. This is because one of the network interface is configured to use DNS server.

    [root@server ~]# grep DNS /etc/sysconfig/network-scripts/ifcfg-*
/etc/sysconfig/network-scripts/ifcfg-eno1:DNS1="127.0.0.1"
[root@server ~]#

    To fix, edit

    vi /etc/sysconfig/network-scripts/ifcfg-eno1

    Remove the line

    DNS1="127.0.0.1"

    Now NetworkManager will not modify /etc/resolv.conf file on boot.

    Or you can set valid DNS servers in network config file like

    [root@server ~]# cat /etc/sysconfig/network-scripts/ifcfg-eno1 | grep DNS
DNS1="1.1.1.1"
DNS2="8.8.8.8"
[root@server ~]#

    If your network configuration use DHCP, set set PEERDNS=no.

    BOOTPROTO=dhcp
PEERDNS=no

    Another solution is to make file immutable with

    chattr +i /etc/resolv.conf

    Related Posts

    Domain Resolver

  • Install Pure-FTPd on CentOS with Virtual Users

    To install Pure-FTPd on CentOS, run

    yum install -y pure-ftpd

    Edit configuration file

    vi /etc/pure-ftpd/pure-ftpd.conf

    To disable anonymous FTP, find

    NoAnonymous                  no

    Replace with

    NoAnonymous                  yes

    To enable Virtual Users, find

    # PureDB                        /etc/pure-ftpd/pureftpd.pdb

    Uncomment the line.

    PureDB                        /etc/pure-ftpd/pureftpd.pdb

    To Allow Apache user to login via FTP, find

    MinUID                      1000

    Replace with

    MinUID                      47

    I set MinUID value to 47, as apache user have UID/GID of 48. By setting MinUID below that apache user should be able to login.

    Set pureftpd to start on Boot

    systemctl enable pure-ftpd

    Restart pure-ftpd

    systemctl start pure-ftpd

    Create a Virual User

    To create a virtual user, run

    pure-pw useradd  USER_NAME_HERE -u apache -g apache -d /var/www/html/

    It will ask you to enter password two times.

    Now run

    pure-pw mkdb
systemctl restart pure-ftpd

    Change Password of an existing Virual User

    pure-pw passwd USER_NAME_HERE

    It will ask you to enter new password.

    Rebuild password database and restart pure-ftpd with

    pure-pw mkdb
systemctl restart pure-ftpd

    Related Posts

    Install pureftpd on Ubuntu

    pureftpd

  • Install vim from source on CentOS

    To install vim from source on the CentOS server, run

    yum -y install  ncurses-devel
cd /usr/local/src
wget https://github.com/vim/vim/archive/master.zip	
unzip master.zip
cd vim-master/src/
./configure
make
make install

    This will install the latest version of Vim. You can start it with the command

    vim

    To get it work with “vi” command, i removed preinstalled vim editor with command

    rpm -e --nodeps  vim-minimal

    Now create a symlink with

    ln -s /usr/local/bin/vim /bin/vi
  • Updating Kernel on Oracle Linux with Ksplice

    Updating Kernel on Oracle Linux with Ksplice

    Oracle Linux come with Ksplice, it allow you to upgrade Kernel with out rebooting.

    To update kernel, run

    uptrack-upgrade

    Example

    Oracle Ksplice

  • Install clamav Antivirus on CentOS 7

    ClamAV is provided by the EPEL repo. Install epel repo 

    yum install -y epel-release

    Install ClamAV with

    yum install clamav

    Back to ClamAV

  • Install OpenLiteSpeed on CentOS

    Install OpenLiteSpeed on CentOS

    To install OpenLiteSpeed web server on CentOS, install repository for your CentOS version

    For CentOS 6

    rpm -Uvh http://rpms.litespeedtech.com/centos/litespeed-repo-1.1-1.el6.noarch.rpm

    For CentOS 7

    rpm -Uvh http://rpms.litespeedtech.com/centos/litespeed-repo-1.1-1.el7.noarch.rpm

    For CentOS 8

    rpm -Uvh http://rpms.litespeedtech.com/centos/litespeed-repo-1.1-1.el8.noarch.rpm

    To install OpenLiteSpeed, run

    yum install openlitespeed

    Before you can install PHP, you need epel repository enabled with

    yum install epel-release

    Install PHP with

    yum install lsphp73 lsphp73-common lsphp73-mysql lsphp73-gd lsphp73-process lsphp73-mbstring lsphp73-xml lsphp73-mcrypt lsphp73-pdo lsphp73-imap lsphp73-soap lsphp73-bcmath lsphp73-json lsphp73-mysqlnd

    Set symlink

    ln -sf /usr/local/lsws/lsphp73/bin/lsphp /usr/local/lsws/fcgi-bin/lsphp5

    Start OpenLiteSpeed with

    /usr/local/lsws/bin/lswsctrl start

    To stop OpenLiteSpeed, run

    /usr/local/lsws/bin/lswsctrl stop

    By default, OpenLiteSpeed will run on port 8088

    http://YOUR_SERVER_IP_HERE:8088

    You can login to Admin Interface at

    http://YOUR_SERVER_IP_HERE:7080
User = admin
PW = 123456

    By default, you see an example application. The configuration file for this is at

    /usr/local/lsws/conf/vhosts/Example/vhconf.conf

    Default DocumentRoot is /usr/local/lsws/Example/html. To change, edit file

    vi /usr/local/lsws/conf/vhosts/Example/vhconf.conf

    Find

    docRoot $VH_ROOT/html/

    Replace $VH_ROOT/html/ with whatever path you need. You need to restart OpenLiteSpeed to make the change go live

    /usr/local/lsws/bin/lswsctrl restart
  • Ubuntu 18.04 MariaDB 10.2 Too many open files

    Ubuntu 18.04 MariaDB 10.2 Too many open files

    On my computer running Ubuntu 18.04, MriaDB stopped working. PHP application i run on my computer failed with error

    SQLSTATE[42S02]: Base table or view not found: 1146 Table 'ok_test.feeds' doesn't exist (SQL: select * from `feeds` where `processed` = 0)

    Application can’t find the table. So i tried to login to MySQL and see if table is there or not. But i get error

    boby@sok-01:~$ mysql
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 2504
Server version: 10.2.30-MariaDB-1:10.2.30+maria~bionic-log mariadb.org binary distribution

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> show databases;
ERROR 1018 (HY000): Can't read dir of '.' (errno: 24 "Too many open files")
MariaDB [(none)]>

    Next i checked if this is due to any MySQL upgrade. I found MySQL got updated today

    root@sok-01:~# grep mariadb /var/log/dpkg.log
2019-12-13 08:02:46 status triggers-pending mariadb-server-10.2:amd64 1:10.2.29+maria~bionic
2019-12-13 08:02:46 upgrade mariadb-common:all 1:10.2.29+maria~bionic 1:10.2.30+maria~bionic
2019-12-13 08:02:46 status half-configured mariadb-common:all 1:10.2.29+maria~bionic
2019-12-13 08:02:46 status unpacked mariadb-common:all 1:10.2.29+maria~bionic
2019-12-13 08:02:46 status half-installed mariadb-common:all 1:10.2.29+maria~bionic

    To fix this error, run

    systemctl edit mysql

    This wil open a text editor. Add following

    [Service]
LimitNOFILE=8192

    Save and quit the editor. Restart MaraDB with

    systemctl restart mysql

    MySQL will work properly now. systemctl edit mysql will create file /etc/systemd/system/mysql.service.d/override.conf

    root@sok-01:~# cat /etc/systemd/system/mysql.service.d/override.conf 
[Service]
LimitNOFILE=8192

root@sok-01:~#
  • OpenLiteSpeed

    OpenLiteSpeed

    OpenLiteSpeed is an open-source version of the popular commercial web server LiteSpeed. OpenLiteSpeed contains all of the essential features found in LiteSpeed Enterprise.

    You can get OpenLiteSpeed from

    https://openlitespeed.org

    Here is a benchmark from the OpenLiteSpeed website that compares OpenLiteSpeed with Nginx.

    OpenLiteSpeed Benchmark

    OpenLiteSpeed configuration file

    /usr/local/lsws/conf/httpd_config.conf

    To start/stop/restart, use

    /usr/local/lsws/bin/lswsctrl start
/usr/local/lsws/bin/lswsctrl stop
/usr/local/lsws/bin/lswsctrl restart
/usr/local/lsws/bin/lswsctrl status

    OpenLiteSpeed web server stores cache in directory /usr/local/lsws/cachedata. This can grow big over time. You can delete this folder to free up space or move it to another partition with free disk space and create a symlink.

    To set/reset the WebAdmin password, run

    /usr/local/lsws/admin/misc/admpass.sh

    Update OpenLiteSpeed

    /usr/local/lsws/admin/misc/lsup.sh -v 1.8.1

    You can login to WebAdmin at

    https://server-ip:7080

    Web Server