File System Management on Cisco IOS Router:

Usually when login to Router we are in Flash File System(Flash drive) of the IOS Router, this drive holds IOS image files and retained on rebooting the router. Usually .bin, .tar, pkg files there, But system file like startup-config, private-config etc resides on nvram.

Output from Flash drive:#dir

Directory of flash:/

    1  -rw-    13937472  Dec 19 2006 06:03:00 +00:00  c1841-ipbase-mz.124-1c.bin
    2  -rw-        1821  Dec 19 2006 06:17:24 +00:00  sdmconfig-18xx.cfg
    3  -rw-     4734464  Dec 19 2006 06:18:12 +00:00  sdm.tar
    4  -rw-      833024  Dec 19 2006 06:18:46 +00:00  es.tar
    5  -rw-     1052160  Dec 19 2006 06:19:20 +00:00  common.tar
    6  -rw-        1038  Dec 19 2006 06:19:58 +00:00  home.shtml
    7  -rw-      102400  Dec 19 2006 06:20:26 +00:00  home.tar
    8  -rw-      491213  Dec 19 2006 06:21:02 +00:00  128MB.sdf
    9  -rw-     1684577  Dec 19 2006 06:22:00 +00:00  securedesktop-ios-3.1.1.27-k9.pkg
   10  -rw-      398305  Dec 19 2006 06:22:44 +00:00  sslclient-win-1.1.0.154.pkg

Output form nvram: #cd nvram:

#dir
Directory of nvram:/

  190  -rw-        1304                    <no date>  startup-config
  191  ----           5                    <no date>  private-config
  192  -rw-        1304                    <no date>  underlying-config
    1  -rw-           0                    <no date>  ifIndex-table
    2  ----          12                    <no date>  persistent-data

196600 bytes total (193191 bytes free)

Commands:

Dir: shows the directories

Copy: Copy command is used to copy the content like in linux. 

Example: copy "source" "destination"

Like: copy nvram:stratup-configuration tftp://IP_of_tftp/directory/file_name

Show file: show file command display information about sa specific file or a file system.

Like: #show file information flash:c1841-ipbase-mz.124-1c.bin

flash:c1841-ipbase-mz.124-1c.bin:
  type is image (elf) []
  file size is 13937472 bytes, run size is 14103140 bytes
  Runnable image, entry point 0x8000F000, run from ram

More: More command works as it works in linux, it shows the content of file.

Like: more nvram:stratup-config

Delete: Delete command works as it know for.

Earse or Formate: Both the command do the same, but depend what type of memory is being used, both commands are used to wipe out the entire content of memory, Erase is mostly used.

CD and PWD: Cd command is used to change directory as in DOS and Linux, this command change your present directory to whatever directory you specified. and PWD command verifies in what directory you are at present.

Mkdir and Rmdir: mkdir is used to make directory and rmdir is used to remove any directory, Not all router and switch offer of creation and deletion of directory, few of then do.