Checking OS Parameters

Check Method

Use the gs_checkos tool provided by MogDB to check the OS status.

Prerequisites

The hardware and network are working properly.
The trust relationship of user root among the hosts is normal.
Only user root is authorized to run the gs_checkos command.

Procedure

Log in to a server as user root.
Run the following command to check OS parameters of servers where the MogDB nodes are deployed:
```
gs_checkos -i A
```
Check the OS parameters to ensure that MogDB has passed the pre-installation check and can efficiently operate after it is installed.

Examples

Before running the gs_checkos command, execute pre-processing scripts by running gs_preinstall to prepare the environment. The following uses parameter A as an example:

gs_checkos -i A
Checking items:
    A1. [ OS version status ]                                   : Normal
    A2. [ Kernel version status ]                               : Normal
    A3. [ Unicode status ]                                      : Normal
    A4. [ Time zone status ]                                    : Normal
    A5. [ Swap memory status ]                                  : Normal
    A6. [ System control parameters status ]                    : Normal
    A7. [ File system configuration status ]                    : Normal
    A8. [ Disk configuration status ]                           : Normal
    A9. [ Pre-read block size status ]                          : Normal
    A10.[ IO scheduler status ]                                 : Normal
    A11.[ Network card configuration status ]                   : Normal
    A12.[ Time consistency status ]                             : Warning
    A13.[ Firewall service status ]                             : Normal
    A14.[ THP service status ]                                  : Normal
Total numbers:14. Abnormal numbers:0. Warning number:1.

The following uses parameter B as an example:

gs_checkos -i B
Setting items:
    B1. [ Set system control parameters ]                       : Normal
    B2. [ Set file system configuration value ]                 : Normal
    B3. [ Set pre-read block size value ]                       : Normal
    B4. [ Set IO scheduler value ]                              : Normal
    B5. [ Set network card configuration value ]                : Normal
    B6. [ Set THP service ]                                     : Normal
    B7. [ Set RemoveIPC value ]                                 : Normal
    B8. [ Set Session Process ]                                 : Normal
Total numbers:6. Abnormal numbers:0. Warning number:0.

Exception Handling

If you use the gs_checkos tool to check the OS and the command output shows Abnormal, run the following command to view detailed error information:

gs_checkos -i A --detail

The Abnormal state cannot be ignored because the OS in this state affects cluster installation. The Warning state does not affect cluster installation and thereby can be ignored.

If the check result for OS version status (A1) is Abnormal, replace OSs out of the mixed programming scope with those within the scope.
If the check result for kernel version status (A2) is Warning, the platform kernel versions in the cluster are inconsistent.
If the check result for Unicode status (A3) is Abnormal, set the same character set for all the hosts. You can add **export LANG=**unicode to the /etc/profile file.
```
vim /etc/profile
```
If the check result for time zone status (A4) is Abnormal, set the same time zone for all the hosts. You can copy the time zone file in the /usr/share/zoneinfo/ directory as the /etc/localtime file.
```
cp /usr/share/zoneinfo/$primary time zone/$secondary time zone /etc/localtime
```
If the check result for swap memory status (A5) is Abnormal, a possible cause is that the swap memory is larger than the physical memory. You can troubleshoot this issue by reducing the swap memory or increasing the physical memory.
If the check result for system control parameter status (A6) is Abnormal, troubleshoot this issue in either of the following two ways:
- Run the following command:
```
gs_checkos -i B1
```
- Modify the /etc/sysctl.conf file based on the error message and run sysctl -p to make it take effect.
```
vim /etc/sysctl.conf
```
If the check result for file system configuration status (A7) is Abnormal, run the following command to troubleshoot this issue:
```
gs_checkos -i B2
```
If the check result for disk configuration status (A8) is Abnormal, set the disk mounting format to rw,noatime,inode64,allocsize=16m.

Run the man mount command to mount the XFS parameter:
```
rw,noatime,inode64,allocsize=16m
```
You can also set the XFS parameter in the /etc/fstab file. For example:
```
/dev/data /data xfs rw,noatime,inode64,allocsize=16m 0 0
```
If the check result for pre-read block size status (A9) is Abnormal, run the following command to troubleshoot this issue:
```
gs_checkos -i B3
```
If the check result for I/O scheduling status (A10) is Abnormal, run the following command to troubleshoot this issue:
```
gs_checkos -i B4
```
If the check result for NIC configuration status (A11) is Warning, run the following command to troubleshoot this issue:
```
gs_checkos -i B5
```
If the check result for time consistency status (A12) is Abnormal, verify that the NTP service has been installed and started and has synchronized time from the NTP clock.
If the check result for firewall status (A13) is Abnormal, disable the firewall. Run the following commands:
- SUSE:
```
SuSEfirewall2 stop
```
- RedHat7:
```
systemctl disable firewalld
```
- RedHat6:
```
service iptables stop
```
If the check result for THP service status (A14) is Abnormal, run the following command to troubleshoot this issue:
```
gs_checkos -i B6
```

Issue