Working with Flash

We have non-volatile storage available to us, this may be an internal flash or pluggable CF, in many devices we have USB. To identify the file systems we have available to us, type the command show file systems

Router#show file systems 
File Systems:

 	Size(b)		Free(b)		Type	Flags	Prefixes
*      64016384		12822561	flash	rw	flash:
29688		23590		nvram	rw	nvram:
Router#

In this case, we have two file systems, flash (which is default) and nvram. On larger devices (for example, chassis-based switches) There can be many spare storage locations in the file system. To view the contents of flash, type show flash

Router# show flash

System flash directory:
File  Length   Name/status
  3   50938004 c2800nm-advipservicesk9-mz.124-15.T1.bin
  2   28282    sigdef-category.xml
  1   227537   sigdef-default.xml
[51193823 bytes used, 12822561 available, 64016384 total]
63488K bytes of processor board System flash (Read/Write)

I can clearly see any files stored in flash, including my software image. I can also see how much free space I have, very important if I want to copy a new IOS image to the flash!

Just to finish off, have a look at the contents of flash and nvram using the dir command….after all we still have not found our start-up configuration file. Try the commands dir flash: and dir nvram: