Preparing the Software and Hardware Installation Environment

This chapter describes the preparations for the installation.

Software and Hardware Requirements
Modifying OS Configuration
Setting Remote Login of User root

Software and Hardware Requirements

This section describes hardware and software requirements of openGauss. It is recommended that servers to be deployed on openGauss have the same software and hardware configurations.

Hardware Requirements

Table 1 describes the minimum hardware requirements of openGauss. When planning the hardware configuration of a product, consider the data scale and expected database response speed. Plan hardware as required.

Table 1 Hardware requirements

Hardware	Description
Minimum memory	Minimum 32 GB of memory is required for function debugging. In performance tests and commercial deployment, the single-instance deployment is performed. It is recommended that the memory be greater than 128 GB. Complex queries require much memory but the memory may be insufficient in high-concurrency scenarios. In this case, it is recommended that a large-memory server or load management be used to restrict concurrences on the system.
CPU	Minimum one 8-core 2.0 GHz CPU is required for function debugging. In performance tests and commercial deployment, the single-instance deployment is performed. It is recommended that one 16-core 2.0 GHz CPU be used. You can set CPUs to hyper-threading or non-hyper-threading mode, but ensure the setting is consistent across all the openGauss nodes.
Hard disk	Hard disks used for installing the openGauss must meet the following requirements: At least 1 GB is used to install the openGauss application package. About 300 MB is used for each host to store metadata. More than 70% of available disk space is reserved to store data. You are advised to configure the system disk to RAID 1 and data disk to RAID 5 and plan four groups of RAID 5 data disks for installing openGauss. RAID configuration is not described in this document. You can configure RAID by following instructions in the hardware vendors' manuals or using common methods found on the Internet. Set Disk Cache Policy to Disabled to avoid data loss in an unexpected power-off. openGauss supports using an SSD with the SAS interface and NVMe protocol deployed in RAID mode as the primary storage device of the database.
Network requirements	Minimum 300 Mbit/s Ethernet is required. You are advised to bond two NICs for redundancy. The configuration is not described in this document. You can configure it by following instructions in the manual provided by the hardware manufacturer or using the methods provided on the Internet. If bonds are configured for the openGauss, ensure the consistency among these bond modes, because inconsistent bond modes may cause openGauss running exceptions.

Software Requirements

Table 2 Software requirements

Software	Description
Linux OS	Arm: openEuler 20.3LTS (recommended) x86: openEuler 20.3LTS CentOS 7.6 NOTE: You are advised to use the English OS. The current installation package can be installed and used only on the English version.
Linux file system	It is recommended that the number of remaining inodes be greater than 1.5 billion.
Tool	bzip2
Python	openEuler: Python 3.7.X is supported. CentOS: Python 3.6.X is supported. NOTE: Python needs to be compiled in --enable-shared mode.

Software Dependency Requirements

#EN-US_TOPIC_0249784577/table11459151513383 lists the software dependency requirements for the openGauss.

You are advised to use the default installation packages of the following dependent software in the listed OS installation CD-ROMs or sources. If the following software does not exist, refer to the recommended versions of the software.

Modifying OS Configuration

Disabling the OS Firewall

To ensure that the openGauss can work properly when the firewall is enabled, related services, protocols, IP addresses, and ports need to be added to the firewall whitelist of each host in the openGauss.

Take openEuler OS as an example. Assume that the openGauss information is listed in Table 1.

Table 1 Information of openGauss

Host Name	Internal IP Address	External IP Address
plat1	192.168.0.11	10.10.0.11
plat2	192.168.0.12	10.10.0.12
plat3	192.168.0.13	10.10.0.13
plat4	192.168.0.14	10.10.0.14
Management network	-	10.10.64.236

Procedure

Currently, EulerOS can be installed only when the firewall is disabled.

Check whether the firewall is disabled.
```
systemctl status firewalld
```
If the firewall is not disabled, go to 2.
If the firewall is disabled, skip 2.

Disable the firewall.

systemctl disable firewalld.service
systemctl stop firewalld.service

Set the value of SELINUX in the /etc/selinux/config file to disabled.
1. Run the vim command to open the config file.
```
vim /etc/selinux/config
```
2. Set the value of SELINUX to disabled.
```
SELINUX=disabled
```
Restart the OS.
```
reboot
```
Repeat steps 1 to 3 on other hosts.

Setting Character Set Parameters

Set the same character set for all database nodes. You can add export LANG=Unicode in the /etc/profile file.

vim /etc/profile

Setting the Time Zone and Time

Set the same time zone for all database nodes by copying the /etc/localtime time zone file to the /usr/share/zoneinfo/ directory.

cp /usr/share/zoneinfo/$Locale/$Time zone /etc/localtime

NOTE: $Locale/$Time zone indicates the locale and time zone to be set, for example, Asia/Shanghai.

Run the date -s command to set the time of each host to the same time. For example:

date -s Mon May 11 16:42:11 CST 2020

NOTE: You can run the date command to query the time zone of the host.

Disabling the Swap Memory

Run the swapoff -a command on each database node to disable the swap memory.

swapoff -a

Setting the NIC MTU

Set the NIC MTU value on each database node to the same value. For X86, the recommended MTU value is 1500. For ARM, the recommended MTU value is 8192.

ifconfig NIC ID mtu Value

During the openGauss installation, the user root is required for remote login. This section describes how to set the user root for remote login.

Modify the PermitRootLogin configuration to enable remote login of user root.
1. Open the sshd_config file.
```
vim /etc/ssh/sshd_config
```
2. Modify permissions of user root using either of the following methods:
  - Comment out PermitRootLogin no.
```
#PermitRootLogin no
```
  - Set the value of PermitRootLogin to yes.
```
PermitRootLogin yes
```
3. Run the :wq command to save the modification and exit.
Modify the Banner configuration to delete the welcome information displayed when you connect to the system. The welcome information affects the return result of remote operations during the installation.
1. Open the sshd_config file.
```
vim /etc/ssh/sshd_config
```
2. Comment out the line where Banner is located.
```
#Banner XXXX
```
3. Run the :wq command to save the modification and exit.
Run the following command to validate the settings:
```
service sshd restart
```
CAUTION: If Redirecting to /bin/systemctl restart sshd.service is displayed, run the /bin/systemctl restart sshd.service command.
Re-log in to the system as user root.
```
ssh xxx.xxx.xxx.xxx
```
NOTE: xxx.xxx.xxx.xxx indicates the IP address of the openGauss installation environment.