[c-nsp] ASR-1001 bgp memory usage

Thu Sep 22 15:07:34 EDT 2011

Hi,

On Thu, 22 Sep 2011, Arie Vayner (avayner) wrote:

> Sorry, just reread my post, and found a small thing to clarify:
> - ASR1001 can go up to 8G of RAM
> - Other ASR1K, with RP2, can go up to 16G RAM
> http://www.cisco.com/en/US/products/ps9343/prod_models_comparison.html

Looks like we can update our ASR1001 to 8GB then.

What bothers me is that we do not seem to have dual ios proceses
running, the box has 4GB of physical ram and the IOS still only
gets 1 GB.  Where do the other 3 GB go.

Is there any boot time sizing feature or is this hard coded ?

Will we get 2 GB usable ram for IOS after updating to 8 GB. Sounds silly.

Greetings
Christian

>
> Arie
>
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Arie Vayner
> (avayner)
> Sent: Thursday, September 22, 2011 08:44
> To: Christian Kratzer; cisco-nsp
> Subject: Re: [c-nsp] ASR-1001 bgp memory usage
>
> Christian,
>
> You are most likely running in software redundancy mode, where the Linux
> kernel takes a portion of the memory, and what is left is split 50/50
> for 2 separate IOS processes.
> You could disable software redundancy, and gain more memory for the
> single IOS process.
>
> Another option is to upgrade the RAM of the router. ASR1K can go up to
> 8G...
>
> Some info about software redundancy can be found here:
> http://www.cisco.com/en/US/docs/routers/asr1000/configuration/guide/chas
> sis/Software_Packaging_Architecture.html#wpxref69339
> http://www.cisco.com/en/US/docs/routers/asr1000/configuration/guide/chas
> sis/High_Availability.html#wp1058945
>
>
> Specifically for BGP, I would suggest you take a look at the output of
> "show ip bgp summary". It shows how much memory BGP actually uses for
> the different pieces of information.
> This means that adding a new peer not necessarily means the same block
> of memory is required for all the information, as network entries and
> paths use separate links memory structures. If you get 2 full feeds,
> most of the network entries would be the same, and there would just be
> an addition path entry (which takes substantially less memory per entry
> compared to a network entry).
>
> This document may give you some further hints:
> http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009
> 4a83.shtml
>
>
> A common memory related optimization for BGP is to disable inbound soft
> reconfiguration. This feature is not really needed today (due to dynamic
> inbound soft reset), and takes a substantial amount of memory if you
> take full routes with all the churn on the internet.
> Here is some info about the feature:
> http://www.cisco.com/en/US/docs/ios/11_3/np1/configuration/guide/1cbgp.h
> tml#wp10995
> http://www.cisco.com/en/US/products/ps6599/products_data_sheet09186a0080
> 087b3a.html
>
>
> Hope this helps.
> Arie
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Christian
> Kratzer
> Sent: Wednesday, September 21, 2011 11:13
> To: cisco-nsp
> Subject: [c-nsp] ASR-1001 bgp memory usage
>
> Hi,
>
> we have a pair of ASR-1001 taking a full bgp feed ipv4 and ipv6 from our
> upstream. We will have a second and third full feed soon and are quite a
> bit surprised by the memory usage of the first full feed.
>
>     Router-1#show memory
> 		    Head    Total(b)     Used(b)     Free(b)   Lowest(b)
> Largest(b)
>     Processor  7FC5CB741010   1235972656   884561540   351411116
> 350518960   350730684
>      lsmpi_io  7FC5CAEE61A8     6295128     6294212         916
> 916         916
>
> I doubt we will fit a further 2 full feeds into that remaining 350 MB.
>
> An old 2821 only used up 300 MB for one and a half full feeds. This box
> seems quite thirsty.
>
> The other router that is currently idle and not yet in the iBGP mesh
> already has on offset of 380MB.
>
>     Router-2#show memory
> 		    Head    Total(b)     Used(b)     Free(b)   Lowest(b)
> Largest(b)
>     Processor  7FBD6A7E2010   1235972656   387423056   848549600
> 817362160   816870148
>      lsmpi_io  7FBD69F871A8     6295128     6294212         916
> 916         916
>
> show versions shows this beast has 4GB memory of which the IOS process
> seems to use 1G
>
>     Cisco IOS Software, IOS-XE Software
> (X86_64_LINUX_IOSD-UNIVERSALK9-M), Version 15.1(1)S, RELEASE SOFTWARE
> (fc1)
>     Technical Support: http://www.cisco.com/techsupport
>     Copyright (c) 1986-2010 by Cisco Systems, Inc.
>     Compiled Mon 22-Nov-10 12:33 by mcpre
>
>     cisco ASR1001 (1RU) processor with 1207124K/6147K bytes of memory.
>     9 Gigabit Ethernet interfaces
>     32768K bytes of non-volatile configuration memory.
>     4194304K bytes of physical memory.
>     7782399K bytes of eUSB flash at bootflash:.
>
> I am currently not sure if I can assign the IOS process more memory
> somewhere or how I could check how the available memory is distributed
> to the subsystems or even if I have dual IOS processes running.
>
> Any pointers ???
>
> Greetings
> Christian
>
>

-- 
Christian Kratzer                      CK Software GmbH
Email:   ck at cksoft.de                  Wildberger Weg 24/2
Phone:   +49 7032 893 997 - 0          D-71126 Gaeufelden
Fax:     +49 7032 893 997 - 9          HRB 245288, Amtsgericht Stuttgart
Web:     http://www.cksoft.de/         Geschaeftsfuehrer: Christian Kratzer