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.

Many times we get questions from new CCNA candidates 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. (0×0) 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 [3814036 bytes used, 4574572 available, 8388608 total] 8192K bytes of processor board System flash (Read/Write)

System flash directory, partition 2: 1 3813972 c2500-y-l.111-6.1 [3814036 bytes used, 4574572 available, 8388608 total] 8192K bytes of processor board System flash (Read/Write)

So now you can just run the “no partition flash” command and make it one big partition? No, not so quick. You have to know by now it can’t be that easy! If you see an IOS image in partition 2, you will have to delete it before you can proceed to the “no partition flash” command otherwise it will error out. You can erase the IOS file in partition 2 by following the example below:

Router# erase flash

Partition Size Used Free Bank-Size State Copy Mode 1 8192K 3724K 4467K 8192K Read ONLY RXBOOT-manual 2 8192K 3724K 4467K 8192K Read/Write Direct

System flash directory, partition 2: File Length Name/status 1 3813972 c2500-y-l.111-6.1 [3814036 bytes used, 4574572 available, 8388608 total]

Erase flash device, partition 2? [confirm] Are you sure? [yes/no]: y

Erasing device… eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee …erased

Router#

Enter the show flash command to verify that the desired Flash memory partitions have been erased: Router# show flash

System flash directory, partition 1: 1 3813972 c2500-y-l.111-6.1 [3814036 bytes used, 4574572 available, 8388608 total] 8192K bytes of processor board System flash (Read/Write)

System flash directory, partition 2: No files in System flash [0 bytes used, 8388608 available, 8388608 total] 8192K bytes of processor board System flash (Read/Write)

Finally, now you are now ready to run the “no partition flash” command. Enter the configuration mode and enter the no partition flash command to create a single flash memory partition, as follows: Router# config t

Enter configuration commands, one per line. End with cntrl/z. Router(config)# no partition flash Router(config)# exit Router#copy run start

Now when you do a show flash you should see the following: System flash directory: 1 3813972 c2500-y-l.111-6.1 [3813972 bytes used, 12963244 available, 16777216 total] 16384K bytes of processor board System flash (Read/Write)

At this point, you can start your IOS upgrade with the “copy tftp flash” command by following that article from our site. You are now on your way to understanding Cisco routers and obtaining your Cisco CCNA certification!

We hope you found this Cisco certification article helpful. We pride ourselves on not only providing top notch Cisco CCNA exam information, but also providing you with the real world Cisco CCNA skills to advance in your networking career.

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