Graceful Bootup with Backup Configuration

When the system’s startup file pica_startup.boot is damaged due to incorrect configuration, the system will fail to startup. PICA8 provides a feature of Graceful Bootup with Backup Configuration to solve this problem. It ensures the device boots up properly and with the backup configuration file pica.conf when startup configuration file pica_startup.boot is damaged due to incorrect configuration.

pica.conf is a backup of the pica_startup.boot file which is saved in directory /pica/config. When the user commits a configuration successfully, the system automatically saves the configuration to the pica_startup.boot file and synchronizes the configuration to the pica.conf file. In the event of an upgrade, the upgraded system will retain the previous pica_startup.boot, and the pica.conf file is a copy of pica_startup.boot file. But in the case of newly installed image, the system will not have the pica_startup.boot, and the pica.conf file is a copy of pica_default.boot file. The boot process is further explained below.

Process of Loading Boot File

Figure 1 Process of loading boot file when system rebooting

As shown in Figure 1, the process of loading boot file when system rebooting is as follows:

1.  The system starts loading the configuration file by parsing the pica_startup.boot file to the syntax.

• If the result of the check is success, system will load pica_startup.boot file, go to step 2.
• If the result of the check is fail, that is, the pica_startup.boot file is damaged, the system will check the syntax of pica.conf, and a syslog message is provided, go to step 3.

2.  Load pica_startup.boot file.

• If load pica_startup.boot file successfully, it will go on with the normal boot process.
• If failed to load pica_startup.boot file, the system will check the syntax of pica.conf, and a syslog message is provided, go to step 3.

3.  Check the syntax of pica.conf file.

• If the result of the check is success, the system will load pica.conf file, go to step 4.
• If the result of the check is fail, that is, the pica.conf file is damaged, the system will load pica_default.boot file, and a syslog message is provided, go to step 5.

4.  Load pica.conf file.

• If load pica.conffile successfully, it will go on with the normal boot process.
• If failed to load pica.conf file, the system will load pica_default.boot file, and a syslog message is provided, go to step 5.

5.  Load pica_default.boot file in directory /pica/bin, and go on with the normal boot process.