DRAM and FLASH

[qwertys21]

I need to replace the IOS on a Cat 3550. Looking at the website I see

DRAM: 64M Flash: 16MB

When I do a show flash or show boot flash, I see the flash but where do I get the DRAM from?

Thanks

[smothuku]

Hi ,

When you execute the command " show version" you can see the size of the DRAM.

i.e

#sh version

Cisco Internetwork Operating System Software

IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(22)EA6, RELEASE SOFTWARE

(fc1)

Copyright (c) 1986-2005 by cisco Systems, Inc.

Compiled Fri 21-Oct-05 01:59 by yenanh

Image text-base: 0x80010000, data-base: 0x80568000

ROM: Bootstrap program is C2950 boot loader

System returned to ROM by power-on

System restarted at 18:04:09 IST Mon Mar 5 2007

System image file is "flash:/c2950-i6q4l2-mz.121-22.EA6.bin"

cisco WS-C2950G-48-EI (RC32300) processor (revision Q0) with 21013K bytes of mem

ory. -----------shows the DRAM Size....

i.e 21013K is the size of DRAM.

Thanks,

satish

[qwertys21]

On the Cat 3550

I see

cisco WS-C3550-48 (PowerPC) processor (revision L0) with 65526K/8192K bytes of memory.

and then I do sh flash

Directory of flash:/

15998976 bytes total (9575424 bytes free)

Pls can you explain which is which?

65526K --

8192K --

15998976 ---

Thanks

[smothuku · Accepted solution]

Hi ,

In every device of Cisco , some part of DRAM is reserved for IOMEM i.e in your case 8192K.

DRAM SIZE = 65526K + 8192K = 64Mb.

Flash size = 16Mb.

Below are for your knowledge's sake.

Before you install a new Cisco IOS Software image on your router, check if your router meets the memory requirements for that image. For this, issue the show version command on your router, and look for these lines:

...

cisco RSP4 (R5000) processor with 65536K/2072K bytes of memory

...

16384K bytes of processor board System flash (Read ONLY)The first line tells you how much Dynamic RAM (DRAM) and Packet memory are installed in your router. Some platforms use a fraction of their DRAM as Packet memory. The memory requirements take this into account, so you have to add both numbers to find the amount of DRAM available on your router (from a memory requirement point of view).

Example 1: Separate DRAM and Packet Memory

...

cisco RSP4 (R5000) processor with 65536K/2072K bytes of memory

...The 4000, 4500, 4700, and 7500 routers have separate DRAM and Packet memory, so you only need to look at the first number. This shows that the router has 65536 K (or 64 M) of DRAM.

Example 2: Combined DRAM and Packet Memory

...

cisco 2611 (MPC860) processor (revision 0x202) with 29696K/3072K bytes of memory

...The 1000, 1600, 2500, 2600, 3600, and 7200 routers use a fraction of DRAM as Packet memory, so you need to add both numbers to find out the real amount of DRAM. In this example, the router has 2969 K + 3072 K = 32768 K (or 32 M) of DRAM.

Example 3: Available Flash Memory

...

cisco RSP4 (R5000) processor with 65536K/2072K bytes of memory

...

16384K bytes of processor board System flash (Read ONLY)The bottom line tells you how much Flash memory is available. Some of it might already be in use. In order to find out the amount of free Flash memory, issue a show flash command:

Router#show flash

System flash directory:

File Length Name/status

1 8407884 c2600-io3s56i-mz.121-6

[8407948 bytes used, 8369268 available, 16777216 total]

16384K bytes of processor board System flash (Read/Write)

Thanks,

satish

[qwertys21]

Thank you very much