Apr 30

SFlow Vs. NetFlow

At a high level both SFlow and NetFlow provide some level of data analysis of traffic flows going through a switch or router. I am not going to go into specific detail about the protocols in this article.

I want to talk about the use of the protocols. On a Brocade device, SFlow can be enabled on every port on the switch (L2 & L3 Ports). On a Cisco device NetFlow is applied only to SVI’s or routed ports. I recently looked into Cisco’s Bridged NetFlow, but I didn’t have the correct line cards, Supervisors, and IOS to run it. Bridged NetFlow became a daunting task of figuring out the hardware and software matrix to run it.


SFlow gives the ability to view flow statistics on every switch port, not just the layer 3 interface. I like this because I can collect statistics on the layer 2 inter-cluster links between servers. I can see all of the traffic going out to my layer 2 edge switches, ultimately to the end user.

When there are problems identified by SFlow, it tells me the layer 2 switch port that the source and destination are connected to. I don’t have to do any research to figure that out.

For those of you that use NetFlow, would you like it to collect layer 2 data?
For those of you that have used both, What do you like better?
Bridged NetFlow, Is working well? or is it taxing your systems?
I don’t have access to Juniper’s JFlow, How does JFlow compare to SFlow or NetFlow?

Apr 23

Cisco Prime NCS – The system is running low on diskspace

If you are running the Cisco Prime NCS or Infrastructure Appliance you may see the following error.

The system is running low on diskspace, please refer to online help to perform disk cleanup

I have received this twice now with my Prime Infrastructure (NCS) appliance. Each time I have found that the upgrade or install files were left in the defaultRepo directory along with all of the back up files.



To view these files you should start by looking in the defaultRepo directory. If you place your backup files or your install files some other place, you will have to look there.

This is what mine looked like

GoatPrime# dir disk:/defaultRepo

Directory of disk:/defaultRepo
1730387219 Dec 28 2012 09:43:50 PI-upgrade-bundle-1.2.1.12.tar.gz
1860472744 Feb 20 2013 15:16:09 PI-upgrade-bundle-1.3.0.20.tar.gz
16575516315 Apr 08 2013 01:19:54 backup-20130408-1200.tar.gpg
16875498727 Apr 10 2013 01:27:00 backup-20130410-1200.tar.gpg
16952316499 Apr 12 2013 01:27:06 backup-20130412-1200.tar.gpg
16893108395 Apr 14 2013 01:21:38 backup-20130414-1200.tar.gpg
17115151700 Apr 16 2013 01:26:38 backup-20130416-1200.tar.gpg
0 Dec 28 2012 09:40:40 ncs_patch-1.1.1.24-upgrade-12.tar.gz
11734212 Feb 20 2013 14:35:23 pi_1.2.1.12_update.tar.gz
0 Dec 28 2012 09:41:54 pi_1.2.1.12_upgrade-12.tar.gz

Usage for disk: filesystem
88297095168 bytes total used
35130003456 bytes free
130144694272 bytes available

To clear out files to create more disk space, you need to delete some files that are no longer needed. This is how you delete the files that are no longer needed.

GoatPrime# delete disk:/defaultRepo/PI-upgrade-bundle-1.2.1.12.tar.gz
GoatPrime# delete disk:/defaultRepo/pi_1.2.1.12_update.tar.gz
Repeat this process until you have deleted all of the files that are no longer needed. If you have too many backup files, you should delete some of the older back up files.

Cisco made an attempt to fix this issue a bit easier then what I presented to you. You can always go to the command line and use the ncs cleanup command. This command deletes files from your system. Read all of the prompts carefully so you don’t delete something that you find important.

Reference: http://www.cisco.com/en/US/docs/wireless/prime_infrastructure/1.2/configuration/guide/tasks.html

**Either way, you use to resolve your problem, be careful and don’t delete files you need.

For the location in Prime to adjust your backup frequency click here.

If this does not solve your problem, please let us know what did fix your problem!!!

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