In preparation of our CCNA exam, we want to make sure we cover the various concepts that we could see on our Cisco CCNA exam. So to assist you, below we will discuss Cisco Router with Multiple Partitions.
Cisco Router with multiple partitions
Many times we get questions from new CCNA canidates stating that they can’t upgrade their Cisco router IOS because there is not enough flash space available on the Cisco router. Although this may be true on occasion, we suggest that you first check a few things on your Cisco router to verify that this is the actual case.
You can generally tell how much flash memory you need on the Cisco router by looking at the size of the IOS file you are looking to load. If you see that the file size is 12 or 14MB, well in those cases you need 16MB of flash by rounding up to the next 8MB increment of flash(ex. 8MB, 16MB, 24MB, 36MB). Now that is a loose rule, but it is pretty safe to go by that most of the time.
As a side note, just because you have enough flash memory to burn the IOS file into flash, that does not mean it will be able to be successfully run on your Cisco router. Why not you may ask? Let’s say you have a Cisco router that has 4MB of DRAM and 16MB of flash. Some of the newer IOS files will require additional DRAM. So not only do you want to check out the IOS file requirements for flash, but you also want to make sure you have met the DRAM memory requirements too.
Ok, so now you have enough DRAM and flash memory in the Cisco router to load the IOS. But it still will not load. You now are getting an error about not enough flash available. But why? You have two 8MB flash sticks in the router for a total of 16MB flash. Well, it most likely is that the flash is partitioned and thus you don’t have enough contiguous space to load the IOS. How can you tell? Well one of two ways. First when your router boots, during the POST you may see something like below. Note the two partitions in bold:
cisco 2500 (68030) processor (revision L) with 14332K/2048K bytes of memory.
Processor board serial number 02094596
X.25 software, Version 2.0, NET2, BFE and GOSIP compliant.
Authorized for Enterprise software set. (0x0)
1 Ethernet/IEEE 802.3 interface.
2 Serial network interfaces.
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash partition 1 (Read ONLY)
8192K bytes of processor board System flash partition 2 (Read/Write)
See how the flash is broken into two 8MB partitions instead of one 16MB contagious partition? That is the issue!
Another way you can tell if you have multiple partitions on your Cisco router is if you are in privileged mode and you run the “show flash” command. The show commands are some commands you will definately want to be familiar with for your CCNA exam. You can see that there are two partitions as in the example below:
Router# show flash
System flash directory, partition 1:
1 3813972 c2500-y-l.111-6.1