Lessons · Network switches · the switch's flash
The switch has a disk, and it can fill up
Flash is the switch's storage: the software image lives there, and `dir flash:` lists what is on it with the free space at the bottom.
Hone is a place to practise programming. This is one of its lessons, written out in full and free to read without an account.
What it is for
An upgrade that runs out of room halfway leaves a part-written file on a box you may not be standing next to. The free-space line is the thirty seconds that prevents it.
How to think about it
Read the listing before you copy anything. Note the size of the image you are bringing and the free figure at the bottom, and if it does not fit, delete deliberately rather than hoping.
Worked example
enableFlash is not visible from user mode.
dir flash:The files, their sizes, and the total and free bytes on the last line. That last line is the one that matters.
show flash:The same listing under its other name. Both are typed by real people; neither is more correct.
show versionNames the image file the switch is actually running, which is not always the newest one on the disk.
Your turn
List what is on the switch's flash.
dir
Console into a switch
The trap
Assuming the switch will make room. There is no housekeeping: a copy that does not fit fails, and nothing is deleted for you.