Déconnexion de la batterie pendant 10 minutes, reconnecter la batterie et puis remise en route sans toucher l’accélérateur et laisser tourner le moteur au ralenti jusqu’au premier démarrage du ventilateur et puis l’arrêt. Le tout prend +/-15 min au total.
Il faut attendre que le ventilo tourne et attendre qu’il s’arrête… (Cela évite une pointe de température au moteur)
This CodePlex project is a simple forms
application that will allow you to easily calculate the maximum SQL
Server memory according to MS best practices
By Default, SQL Server is set to use max 2TB of Ram, however I am
sure that in 2013 no one has that much! This effectively means that
SQL can consume all of the RAM in your server leaving nothing for the
OS or other applications. This can cause performance issues. Here is
how Thomas Larock, from SQL Rockstar explains it:
SQL Server (and other
database systems such as Oracle and Sybase) need to read data pages
into their internal memory before they can be used. Of course your
server needs memory to operate as well. When your database engine and
your server are competing for the same memory resources, you get bad
performance. You want your server and your database engine to be like
dancing partners, and less like my kids fighting over the last
There is a nice formula to define how much RAM you should
dedicate to all the SQL instances on the server, to make sure there
is enough left for the OS but… unfortunately it’s not easy!
SQL Max Memory = TotalPhyMem – (NumOfSQLThreads * ThreadStackSize) – (1GB * CEILING(NumOfCores/4)) – OS Reserved
ThreadStackSize = 2MB on x64 or 4 MB on 64-bit (IA64)
OS Reserved = 20% of total ram for under if system has 15GB. 12.5% for over 20GB
I know, it’s not easy, and what I think it’s missing is a part really dedicated for the OS. To help you set the correct values, I developed this utility that let’s you easily calculate how much Memory you actually got available for all your SQL instances.
Pour un serveur SQL Server 2016 de 6 CPU et 24Go de RAM allouée :
NumOfSQLThreads = 256 + (6 – 4) * 8, donc 272Mo ThreadStackSize = On est en x64 donc 2Mo OS Reserved = Pour 24Go de RAM, donc 3Go
On a donc : SQL Max Memory = 24Go – 576Mo – 2Go – 3Go = 18,5G Maxi !
Update your operating system packages (software). This is an
important first step because it ensures you have the latest updates and
security fixes for your operating system’s default software packages:
sudo yum upgdate -y
Install some essential packages that are necessary for basic administration of the CentOS operating system:
8 is distributed with PHP 7.2. This version supports most of the modern
PHP applications, but will no longer be actively maintained as of
November 2019. The newer PHP versions are available from the Remi repository.
Enable the Remi repository
you’re going to install the distro stable PHP version 7.2, skip this
step. Otherwise, if you want to install PHP 7.3 or 7.4 enable the Remi
repository by running the following command as root or user with sudo privileges:
Once the installation is complete, run the command below to get a list of all available PHP versions:
sudo dnf module list php
The output will show a list of all available modules, including the associated stream, version, and installation profiles.
Last metadata expiration check: 0:02:11 ago on Fri 18 Oct 2019 08:31:43 PM UTC.
CentOS-8 - AppStream
Name Stream Profiles Summary
php 7.2 [d][e] common [d], devel, minimal PHP scripting language
Remi's Modular repository for Enterprise Linux 8 - x86_64
Name Stream Profiles Summary
php remi-7.2 common [d], devel, minimal PHP scripting language
php remi-7.3 common [d], devel, minimal PHP scripting language
php remi-7.4 common [d], devel, minimal PHP scripting language
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled
The default PHP module is set to PHP 7.2. To install a newer PHP release, enable the appropriate version:
7.2 is available for installation from the default CentOS 8
repositories. If you want to install more recent version you need to
enable the Remi repository.
Add php test page:
echo '<?php phpinfo();' | sudo tee /var/www/html/info.php
Browse to your server IP on http://localhost/info.php to see php in action.
Enjoy using PHP 7.2 on CentOS 8 / RHEL 8
By default, CentOS 8/RHEL 8 forbids public access to port 80. To
allow other computers to access the web page, we need to open port 80 in
firewalld, the dynamic firewall manager on RHEL/CentOS. Run the
following command to open port 80.
The --permanent option will make this firewall rule
persistent across system reboots. Next, reload the firewall daemon for
the change to take effect.
systemctl reload firewalld
Now the Apache web page is accessible publicly.
Finally, we need to make user apache as the owner of web directory. By default it’s owned by the root user.
chown apache:apache /var/www/html -R
Step 2 – Installing MariaDB
Now, it’s time to install the database server
sudo yum install mariadb-server mariadb
When the MariaDB is installed, issue the command below to start it
sudo systemctl start mariadb
Enable auto start at system boot time.
systemctl enable mariadb
systemctl status mariadb
● mariadb.service - MariaDB 10.3 database server
Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled)
Active: active (running) since Sat 2019-10-12 09:02:53 UTC; 33s ago
Main PID: 18608 (mysqld)
Status: "Taking your SQL requests now..."
Tasks: 30 (limit: 5092)
└─18608 /usr/libexec/mysqld --basedir=/usr
“Enabled” indicates that auto start at boot time is
enabled and we can see that MariaDB server is running. Now we need to
run the security script.
When it asks you to enter MariaDB root password, press Enter key as the root password isn’t set yet. Then enter y to set the root password for MariaDB server.
Next, you can press Enter to answer all remaining questions, which
will remove anonymous user, disable remote root login and remove test
database. This step is a basic requirement for MariaDB database
security. (Note that the letter Y is capitalized, which means it’s the default answer.)
Now you can run the following command and enter MariaDB root password to log into MariaDB shell.
mysql -u root -p
Connect to MariaDB shell as the root user:
sudo mysql -u root -p
# Enter password
Create an empty MariaDB database and user for Cachet and remember the credentials:
MariaDB> CREATE DATABASE cachet;
MariaDB> GRANT ALL ON cachet.* TO 'dbuser_cachet' IDENTIFIED BY 'password';
MariaDB> FLUSH PRIVILEGES;
Securing your website with HTTPS is not necessary, but it is a good
practice to secure your site traffic. In order to obtain a TLS
certificate from Let’s Encrypt we will use acme.sh client. Acme.sh is a
pure UNIX shell software for obtaining TLS certificates from Let’s
Encrypt with zero dependencies.
Download and install acme.sh:
sudo su - root
git clone https://github.com/Neilpang/acme.sh.git
./acme.sh --install --accountemail firstname.lastname@example.org
source ~/.bashrccd ~
Check acme.sh version:
Obtain RSA and ECC/ECDSA certificates for your domain/hostname: