Upgrade considerations for customized configuration files in the /etc directory

德cember 12, 2022

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The following configuration files are supported to be modified in the/etcdirectory:

inetd.conf
syslog.conf
newsyslog.conf
ntp.conf
crontab
host.conf
hosts
ttys
sshd_config
httpd . conf
monitrc
rc.conf
ssh_config
localtime
issue
issue.net
ldap.conf
motd

Note:

New files might be added to the above list depending on the Citrix ADC build running on the appliance. You can display an updated list of files by running the following shell command in the Citrix ADC command line interface:

grep NSETC= /etc/rc

If you have modified any of the configuration files in the/etcdirectory and copied it to the/nsconfigdirectory, to maintain persistency, the Citrix ADC appliance creates a symlink in/etcpointing to the file in/nsconfig.

For example:/etc/httpd.conf -> /nsconfig /httpd.conf

A release package might contain its own version of the configuration files in the/etcdirectory. These configuration files include important updates that are required for the Citrix ADC appliance to properly function. Upgrading a Citrix ADC appliance to a release replaces the configuration files in the/etcdirectory with the configuration files containing the release updates.

Consider an example of a customized configuration file,example.conf, which is present in the/etcdirectory. Theexample.conffile is copied to the/nsconfigdirectory to maintain persistency. The Citrix ADC appliance creates a symlink in/etcpointing to the file in/nsconfig:/etc/example.conf -> / nsconfig /example.conf

Also, a release package includes its own version ofexample.conf, which contains important updates. The following behavior is observed when you upgrade the Citrix ADC appliance to the release:

Because the symlink/etc/example.confis already present, the Citrix ADC appliance does not place the release package copy of theexample.confin the/etcdirectory during the upgrade process.

As the release package copy ofexample.confcontains important updates, the absence of it in the/etcdirectory can cause the Citrix ADC appliance to fail or to not properly function.

Steps to preserve upgrade changes and customization

To ensure that both release updates and your customizations are not lost, perform the following steps:

Pre-upgrade steps:
- Back up customized file before upgrade
- Remove persistency of customized file before upgrade
Post-upgrade steps:
- Apply customizations to upgraded file and add persistency after upgrade
  
  Important:
  
  Do NOT directly replace your customized file in the/etcfolder. Directly replacing a/etcfile with the back-up customized file removes any release updates added to the file during the upgrade process.

Back up customized file before upgrade

Take a backup of the customized files present in the/nsconfigdirectory before upgrading the appliance.

克雷亚te a/var/nsconfig_backupdirectory and move the customized files to this directory. That is, move any files that you modified in the/etc目录和复制到/nsconfigby running the following command at the shell prompt:

mv /nsconfig/ /var/nsconfig_backup/

Example:

mv /nsconfig/httpd.conf /var/nsconfig_backup/

Remove persistency of customized file before upgrade

德lete the/etcsymlinks that are pointing to the/nsconfigfiles before upgrading the appliance.

Check the existing symlinks in the/etcdirectory by running the following command at the shell prompt:
```
ls -la /etc 
```
德lete a/etcsymlink pointing to a/nsconfigfile by running the following command at the shell prompt:
```
unlink /etc/ 
```
Example:
```
unlink /etc/httpd.conf 
```
Verify that the symlink is removed by running the following command at the shell prompt:
```
cat /etc/ 
```
Example:
```
cat /etc/httpd.conf 
```
This command does not display any content if the symlink is removed.

Apply customizations to upgraded file and add persistency after upgrade

If you have taken a backup of any modified/nsconfigconfig file to the/var/nsconfig_backup, do the following after upgrading the appliance:

Compare the file present in the/var/nsconfig_backupand the/etcdirectories. Manually add the appropriate changes to the/etcfile already containing the release updates.

Important:

Directly replacing the/etcfile with the/var/nsconfig_backupfile removes any release updates added to the file during the upgrade process. This removal of updates can cause the related Citrix ADC functionalities to fail or to not work properly.
To maintain persistency, copy the updated file present in the/etcdirectory to the/nsconfigdirectory by running the following command at the shell prompt:
```
cp /etc/ /nsconfig/ 
```
Example:
```
cp /etc/httpd.conf /nsconfig/ 
```
Repeat the above two steps for each customized file present in the/var/nsconfig_backupdirectory.
Restart the appliance to put the changes into effect.

The official version of this content is in English. Some of the Citrix documentation content is machine translated for your convenience only. Citrix has no control over machine-translated content, which may contain errors, inaccuracies or unsuitable language. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, suitability, or correctness of any translations made from the English original into any other language, or that your Citrix product or service conforms to any machine translated content, and any warranty provided under the applicable end user license agreement or terms of service, or any other agreement with Citrix, that the product or service conforms with any documentation shall not apply to the extent that such documentation has been machine translated. Citrix will not be held responsible for any damage or issues that may arise from using machine-translated content.

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Upgrade considerations for customized configuration files in the /etc directory

德cember 12, 2022

Contributed by:

德cember 12, 2022

Contributed by:

Upgrade considerations for customized configuration files in the /etc directory

Steps to preserve upgrade changes and customization

Back up customized file before upgrade

Remove persistency of customized file before upgrade

Apply customizations to upgraded file and add persistency after upgrade

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