System information

Operation 1-25
Software Release 2.0.1
C613-03018-00 REV A
deleted, read and written by any router module. Files can also be manipulated
directly using the command line interface. This allows FLASH to be used to
store any type of data, including releases, patches, configurations and logs.
Physical Characteristics
FLASH memory is a special type of nonvolatile memory which can be erased
and reprogrammed many times in-situ. FLASH memory has advantages over
other types of nonvolatile memory in that it has a very large storage capacity
and it does not require power from a battery to retain stored data. The main
limitations of FLASH memory are that it has a fixed erase block size, so
individual bytes can not be changed without first clearing a whole block of
data, and a limit on the number of erase cycles that can be performed.
However, the erase limit is very high, typically at least 100000 cycles, which
would allow three erases per day for 100 years before the limit was exceeded.
In the router, FLASH memory can be installed directly onto the system board
during manufacture, or subsequently as FLASH SIMM sticks mounted on the
80-pin SIMM connector.
The FLASH SIMM sticks used are specially designed for the router and must be
obtained from your distributor or reseller.
The presence and amount of FLASH memory installed is displayed using the
command:
SHOW SYSTEM
More detailed information about the FLASH memory can be displayed using
the command:
SHOW FLASH PHYSICAL
The File Subsystem
The file subsystem provides a consistent file-based interface to all physical
memory devices on the router used for data storage, including NVS and
FLASH memory. The file subsystem allows data, such as code releases, licence
information and configuration scripts, to be stored on the router in a file
structure and manipulated in the same way with the same commands,
regardless of whether the file is physically stored in NVS or FLASH.
File Naming Conventions
The file subsystem provides a flat file system—directories are not supported.
Files are uniquely identified by a file name of the form:
[device:]filename.ext
where:
■ device specifies the physical memory device on which the file is stored, and
must be one of NVS or FLASH. If device is specified, it must be separated
from the rest of the file name by a colon (“:”). If device is not specified, the
default is FLASH.