Core issue
This message indicates that the configuration block has been restored from backup. [chars] is the block type that can be modified by the user or the process.
A corrupted block in NVRAM has been identified and restored. The NVRAM is checked on an hourly basis for corrupted blocks. If one is found, it is restored by a copy in DRAM to ensure that the configuration is not lost.
For more information, refer to Common CatOS Error Messages on Catalyst 6500/6000 Series Switches.
Resolution
The message is informational only. Normally, this is a one-time occurrence. If this message is seen very frequently, contact Cisco Technical Support for further investigation.