Flash Features

The software contains a number of features that optimize the way the router restores its configuration if it is shut down improperly:

• The router tracks improper shutdowns.
• After an improper shutdown, the router runs an investigation of the file allocation table (FAT) the next time it reboots.
• The router creates backups of critical files.
• When you install a new flash card or restart the router after shutting it down incorrectly, a utility scans the flash card to detect corrupt sectors. If the utility finds files or directories that contain corrupt sectors, it removes the files and directories, because they can no longer be used. The utility also fixes problems with unused sectors. If the utility cannot correct a corrupt sector, it marks the sectors so that they cannot be reused. Errors in the boot block, FAT, or root directory are fatal and cannot be corrected by the scan utility.
• In a router that contains two SRP modules, if the scanning utility detects corrupt sectors in flash on the primary SRP module during rebooting, the primary SRP module reboots again. Both SRP modules now have standby status and reboot. The first SRP module to complete rebooting becomes the primary. Because the former redundant module started to reboot first, it likely becomes the primary. When the former primary module has rebooted and the scan utility has fixed corrupt sectors in its flash card, the SRP modules will synchronize. Any files or directories removed by the scan utility are restored during the synchronization.
• If you reboot the router before it has completely written configuration updates to the flash card, the router starts with the last saved configuration. If you reboot the router after it has written the configuration updates to the flash card, but before it has applied those updates to actual configuration data, the configuration update process resumes immediately following the reboot and is completed before any application accesses its configuration data.

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