Migrating opensource Zimbra 8.6.0 on Centos 6.8 to Zimbra 8.7.1 on Centos 7 safely and with no downtime

 Backup, CentOS 7 / RHEL 7, Clusterweb, ClusterWeb, Hospedagem, Leitura Recomendada, Linux, Profissional de TI, Programação, Redes, Servidor de E-mail, Zimbra  Comentários desativados em Migrating opensource Zimbra 8.6.0 on Centos 6.8 to Zimbra 8.7.1 on Centos 7 safely and with no downtime
dez 032020

A bit of history for the context

After running a Zimbra mail server in a 500Gb Virtual Machine, for about 4 years, the server started feeling a bit crowded and with  #df -h reporting less than 50Gb of space left, it was time to move to a larger machine.

The version I was (and still am) running is the open source version, there are no migration tools available as part of the package, although you can find plenty of tutorials on the web forums about how to rsync stuff between the old and the new server. I was not comfortable with that. For starters, there would be down time involved, but apart from that I would have to rsync between two identical servers, meaning that the new server would still need to be zimbra 8.6 and running on an identical Centos 6 machine.

There was also the fact that some time ago, the server did a very bad shutdown (due to a power failure), and the database had been corrupted, and every so often a problem or two would crop up in the logs. This became very evident when an upgrade to 8.7.1 failed miserably, and the only thing that saved the day was the backup from the previous night ! I was afraid that most likely, an rsync migration would also transfer the problematic data, and that it would be back to haunt me down the road.

Since I was going to have to go through all the aches and  pains of  a server migration  I wanted to end up not only with more space,  but also to move to a newer O.S., and a newer release, so rsync was out of the question.

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Install Apache2, MariaDB And PHP 7.2 With PhpMyAdmin On Ubuntu 16.04 | 18.04 | 18.10 (LAMP + PhpMyAdmin)

 Apache2, Banco de Dados, CentOS 7 / RHEL 7, Clusterweb, ClusterWeb, Debian, Hospedagem, Leitura Recomendada, Linux, Profissional de TI, Ubuntu  Comentários desativados em Install Apache2, MariaDB And PHP 7.2 With PhpMyAdmin On Ubuntu 16.04 | 18.04 | 18.10 (LAMP + PhpMyAdmin)
nov 072019

This brief tutorial shows students and new users how to install LAMP + phpMyAdmin on Ubuntu 16.04 | 18.04 | 18.10 servers….

LAMP is an acronym for Linux (Ubuntu), Apache2 HTTP Server, MariaDB or MySQL Database Server and PHP Scripting Language… It is a group of open source software and building blocks of many of the web applications and majority of the content management systems (CMS) in use today…

phpMyAdmin is a web-based tool that allows you to interact with MariaDB databases, manage user accounts and privileges, execute SQL-statements, import and export data and much, much more.

If you’re going to be developing any PHP based applications or websites, then you’re probably going to be using the LAMP and phpMyAdmin allows you to easily manage your databases from your favorites web browsers…

This brief tutorial is going to show students and new users how to install Apache2, MariaDB, PHP with phpMyAdmin support on Ubuntu Linux 16.04 | 18.04 and 18.10 servers…

To get started with installing the LAMP Stack, follow the steps below:

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fev 112019

On some of our development servers, we run many instances of the Apache httpd web server on the same system. By “many”, I mean 30 or more separate Apache instances, each with its own configuration file and child processes. This is not unusual on DevCamps setups with many developers working on many projects on the same server at the same time, each project having a complete software stack nearly identical to production.

On Red Hat Enterprise Linux 5, with somewhere in the range of 30 to 40 Apache instances on a server, you can run into failures at startup time with this error or another similar one in the error log:

[error] (28)No space left on device: Cannot create SSLMutex

The exact error will depend on what Apache modules you are running. The “space left on device” error does not mean you’ve run out of disk space or free inodes on your filesystem, but that you have run out of SysV IPC semaphores.

You can see what your limits are like this:

# cat /proc/sys/kernel/sem
250 32000 32 128

I typically double those limits by adding this line to /etc/sysctl.conf:

kernel.sem = 500 64000 64 256

That makes sure you’ll get the change at the next boot. To make the change take immediate effect:

# sysctl -p

With those limits I’ve run 100 Apache instances on the same server.

out 072015

cPanel logs most activity that happens on a server to log files so you can go back and review log entries for problems, instead of having to be on the server at the time of them happening.

This guide will cover the locations of the log files for things such as access logs, Apache web server logs, email logs, error logs, ftp logs, MySQL logs, and WHM logs.

If you’d like to have a poster of the 2013 cPanel logs location reference, you can request them from cPanel directly.

You can also view a digitial copy of this poster directly online at go.cPanel.net/logposter.

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Install NTOP on Debian and Configure to Use NetFlow on Mikrotik RouterOS

 Apache2, Clusterweb, Leitura Recomendada, Linux, Mikrotik, Profissional de TI, Redes, Segurança  Comentários desativados em Install NTOP on Debian and Configure to Use NetFlow on Mikrotik RouterOS
jun 182014

Ntop is a network monitoring tool similar to Unix top, which shows network traffic usage. It can act as a NetFlow collector for flows generated by routers such as Cisco or Mikrotik. NetFlow is an industry standard for flow-based traffic monitoring.

We will install and configure Ntop to collect flows generated by Mikrotik router. Note: “Ntop” != “NtopNG”.

Install Pre-required Software

We’re using Debian Wheezy:

$ uname -rv
3.2.0-4-686-pae #1 SMP Debian 3.2.51-1

Update the system first:

# apt-get update && apt-get upgrade -uV

Install required software:

# apt-get install libtool automake autoconf make build-essential python-dev subversion

Install external tools and libraries required by ntop:

# apt-get install libpcap-dev libgdbm-dev zlib1g-dev libgeoip-dev libgraphviz-dev \
> graphviz rrdtool librrd-dev

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