Core issue
This issue is documented in Cisco bug ID CSCec56677. It occurs when the write memory command is issued.
The root cause of this bug is Cisco bug ID CSCeb45692.
This bug indicates that whenever the write memory command is issued, a small amount of free space in the NVRAM is wasted and lost. These error messages are displayed:
switch#copy running-config startup-config
Destination filename [startup-config]?
Building configuration...
%Warning: Saving this config to nvram may corrupt any network management or security files stored at the end of nvram. Continue? [no]:
Switch#wr mem
Building configuration...
% Warning: Saving this config to nvram may corrupt any network management or
security files stored at the end of nvram. Continue? [no]:
Resolution
To resolve this issue, upgrade the Cisco IOS Software Release to .12.1(20)EA1a or later.
For a workaround, save the contents of the NVRAM, and issue the write erase command. This resets the file system on NVRAM and resolves the issue. Issuing the command also eliminates any corruption of the file structures found on the NVRAM.
To download Cisco IOS image 12.1(20)EA1a or later, refer to Downloads.
