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Introduction to Cisco NX-OS

Chapter Description

This chapter provides an introduction and overview of NX-OS and a comparison between traditional IOS and NX-OS configurations and terminology.

Managing System Files

Directories can be created on bootflash: and external flash memory (slot0:, usb1:, and usb2:); you can also navigate through these directories and use them for files. Files can be created and accessed on bootflash:, volatile:, slot0:, usb1:, and usb2: file systems. Files can be accessed only on the system: file systems. Debug file system can be used for debug log files specified in the debug logfile command. System image files, from remote servers using FTP, Secure Copy (SCP), Secure Shell FTP (SFTP), and TFTP can also be downloaded.

File Systems

Table 1-1 outlines the parameters for the syntax for specifying a local file system, which is:

filesystem:[//module/]

Table 1-1. Syntax for Specifying a Local File System

File System Name

Module

Description

Bootflash

sup-active

sup-local

Internal CompactFlash memory located on the active supervisor module used for storing image files, configuration files, and other miscellaneous files. The initial default directory is bootflash.

Bootflash

sup-standby

sup-remote

Internal CompactFlash memory located on the standby supervisor module used for storing image files, configuration files, and other miscellaneous files.

slot0

Not applicable

External CompactFlash memory installed in a supervisor module used for storing system images, configuration files, and other miscellaneous files.

volatile

Not applicable

Volatile random-access memory (VRAM) located on a supervisor module used for temporary or pending changes.

Nvram

Not applicable

Nonvolatile random-access memory (NVRAM) located on a supervisor module used for storing the startup-configuration file.

Log

Not applicable

Memory on the active supervisor that stores logging file statistics.

system

Not applicable

Memory on a supervisor module used for storing the running-configuration file.

debug

Not applicable

Memory on a supervisor module used for debug logs.

usb1

Not applicable

External USB flash memory installed in a supervisor module used for storing image files, configuration files, and other miscellaneous files.

usb2

Not applicable

External USB flash memory installed in a supervisor module used for storing image files, configuration files, and other miscellaneous files.

Example 1-9 demonstrates some file system commands and how to copy a file.

Example 1-9. File System Commands/Copying a File

N7010-1# dir bootflash:
        311     Jun 20 05:15:05 2009  MDS20090619155920643.lic
        309     Jun 20 05:15:56 2009  MDS20090619155929839.lic
    2470887     Aug 01 08:13:35 2009  dp42
    8533440     Apr 17 23:17:14 2009  lacp_tech_all.log
     308249     Aug 01 09:08:39 2009  libcmd.so
        134     Jun 19 23:06:53 2009  libglbp.log
        175     Jun 20 04:14:22 2009  libotm.log
      49152     Jun 19 22:50:53 2009  lost+found/
   87081184     Jan 02 06:21:20 2008  congo-s1-dk9.4.0.2.bin
   87755113     Dec 11 13:35:25 2008  congo-s1-dk9.4.0.4.bin
   92000595     Apr 16 21:55:19 2009  congo-s1-dk9.4.1.4.bin
   92645614     Apr 08 06:08:35 2009  congo-s1-dk9.4.1.5.bin
   92004757     Jun 02 04:29:19 2009  congo-s1-dk9.4.1.5E2.bin
   99851395     Aug 03 05:17:46 2009  congo-s1-dk9.4.2.0.601.bin
  100122301     Aug 12 04:42:13 2009  congo-s1-dk9.4.2.1.bin
    9905740     Jan 02 06:21:29 2008  congo-s1-epld.4.0.2.img
    9730124     Dec 11 13:42:30 2008  congo-s1-epld.4.0.4.img
   23584768     Jan 02 06:21:26 2008  congo-s1-kickstart.4.0.2.bin
   23785984     Dec 11 13:34:37 2008  congo-s1-kickstart.4.0.4.bin
   24718848     Apr 16 21:52:40 2009  congo-s1-kickstart.4.1.4.bin
   25173504     Apr 08 06:00:57 2009  congo-s1-kickstart.4.1.5.bin
   23936512     Aug 03 05:03:13 2009  congo-s1-kickstart.4.1.5E2.bin
   25333248     Aug 03 05:18:37 2009  congo-s1-kickstart.4.2.0.601.bin
   25234944     Aug 12 04:40:52 2009  congo-s1-kickstart.4.2.1.bin
      12558     Aug 01 08:51:22 2009  shrun
     916893     Apr 17 23:23:03 2009  stp_tech.og
       4096     Dec 11 14:04:50 2008  vdc_2/
       4096     Dec 11 14:04:50 2008  vdc_3/
       4096     Dec 11 14:04:50 2008  vdc_4/
     592649     Apr 17 23:18:16 2009  vpc_tech.log
        942     Jul 10 09:45:27 2009  wireshark
Usage for bootflash://sup-local
  982306816 bytes used
  827592704 bytes free
 1809899520 bytes total
N7010-1# dir bootflash://sup-remote
      12349     Dec 05 02:15:33 2008  7k-1-vdc-all.run
       4096     Apr 04 06:45:28 2009  eem/
      18180     Apr 02 23:47:26 2009  eem_script.cfg
   99851395     Aug 03 05:20:20 2009  congo-s1-dk9.4.2.0.601.bin
  100122301     Aug 12 04:46:18 2009  congo-s1-dk9.4.2.1.bin
      19021     Apr 03 21:04:50 2009  eem_script_counters.cfg
      19781     Apr 05 23:30:51 2009  eem_script_iptrack.cfg
      29104     Jun 19 22:44:51 2009  ethpm_act_logs.log
          0     Jun 19 22:44:51 2009  ethpm_syslogs.log
        175     Jun 20 04:14:37 2009  libotm.log
      49152     Jun 19 22:38:45 2009  lost+found/
   87755113     Apr 07 23:54:07 2009  congo-s1-dk9.4.0.4.bin
   92000595     Apr 16 21:55:19 2009  congo-s1-dk9.4.1.4.bin
   92645614     Apr 08 06:08:35 2009  congo-s1-dk9.4.1.5.bin
   92004757     Jun 02 04:29:19 2009  congo-s1-dk9.4.1.5E2.bin
   10993389     Mar 22 04:55:13 2009  congo-s1-epld.4.1.3.33.img
   23785984     Apr 07 23:47:43 2009  congo-s1-kickstart.4.0.4.bin
   24718848     Apr 16 21:52:40 2009  congo-s1-kickstart.4.1.4.bin
   25173504     Apr 08 06:00:57 2009  congo-s1-kickstart.4.1.5.bin
   23936512     Jun 02 04:26:35 2009  congo-s1-kickstart.4.1.5E2.bin
   25333248     Aug 03 05:19:26 2009  congo-s1-kickstart.4.2.0.601.bin
   25234944     Aug 12 04:45:24 2009  congo-s1-kickstart.4.2.1.bin
        310     Sep 19 03:58:55 2008  n7k-rhs-1.lic
      12699     Jan 23 14:02:52 2009  run_vpc_jan22
      11562     Mar 13 07:52:42 2009  startup-robert-cfg
      16008     Mar 12 02:02:40 2009  startup-vss-cfg
      17315     Mar 19 06:24:32 2009  startup-vss-cfg_roberto_mar18
         99     Apr 04 06:51:15 2009  test1
       9991     Jun 19 23:12:48 2009  vdc.cfg
       4096     Jan 22 13:37:57 2009  vdc_2/
       4096     Jan 22 00:40:57 2009  vdc_3/

       4096     Sep 11 12:54:10 2008  vdc_4/
     111096     Dec 20 04:40:17 2008  vpc.cap
          0     Feb 03 08:02:14 2009  vpc_hw_check_disable
      18166     Apr 03 03:24:22 2009  vpc_vss_apr02
      18223     Apr 02 22:40:57 2009  vss_vpc_apr2

Usage for bootflash://sup-remote
  863535104 bytes used
  946364416 bytes free
 1809899520 bytes total
N7010-1# copy bootflash://sup
bootflash://sup-1/        bootflash://sup-active/   bootflash://sup-remote/
bootflash://sup-2/        bootflash://sup-local/    bootflash://sup-standby/

N7010-1# copy bootflash://sup-local/congo-s1-epld.4.0.4.img bootflash://sup-
remote/congo-s1-epld.4.0.4.img
N7010-1# dir bootflash://sup-remote
      12349     Dec 05 02:15:33 2008  7k-1-vdc-all.run
       4096     Apr 04 06:45:28 2009  eem/
      18180     Apr 02 23:47:26 2009  eem_script.cfg
      19021     Apr 03 21:04:50 2009  eem_script_counters.cfg
      19781     Apr 05 23:30:51 2009  eem_script_iptrack.cfg
      29104     Jun 19 22:44:51 2009  ethpm_act_logs.log
          0     Jun 19 22:44:51 2009  ethpm_syslogs.log
        175     Jun 20 04:14:37 2009  libotm.log
      49152     Jun 19 22:38:45 2009  lost+found/
   87755113     Apr 07 23:54:07 2009  congo-s1-dk9.4.0.4.bin
   92000595     Apr 16 21:55:19 2009  congo-s1-dk9.4.1.4.bin
   92645614     Apr 08 06:08:35 2009  congo-s1-dk9.4.1.5.bin
   92004757     Jun 02 04:29:19 2009  congo-s1-dk9.4.1.5E2.bin
   99851395     Aug 03 05:20:20 2009  congo-s1-dk9.4.2.0.601.bin
  100122301     Aug 12 04:46:18 2009  congo-s1-dk9.4.2.1.bin
    9730124     Aug 12 22:02:57 2009  congo-s1-epld.4.0.4.img
   10993389     Mar 22 04:55:13 2009  congo-s1-epld.4.1.3.33.img
   23785984     Apr 07 23:47:43 2009  congo-s1-kickstart.4.0.4.bin
   24718848     Apr 16 21:52:40 2009  congo-s1-kickstart.4.1.4.bin
   25173504     Apr 08 06:00:57 2009  congo-s1-kickstart.4.1.5.bin
   23936512     Jun 02 04:26:35 2009  congo-s1-kickstart.4.1.5E2.bin
   25333248     Aug 03 05:19:26 2009  congo-s1-kickstart.4.2.0.601.bin
   25234944     Aug 12 04:45:24 2009  congo-s1-kickstart.4.2.1.bin
        310     Sep 19 03:58:55 2008  n7k-rhs-1.lic
      12699     Jan 23 14:02:52 2009  run_vpc_jan22
      11562     Mar 13 07:52:42 2009  startup-robert-cfg
      16008     Mar 12 02:02:40 2009  startup-vss-cfg
      17315     Mar 19 06:24:32 2009  startup-vss-cfg_roberto_mar18
         99     Apr 04 06:51:15 2009  test1

       9991     Jun 19 23:12:48 2009  vdc.cfg
       4096     Jan 22 13:37:57 2009  vdc_2/
       4096     Jan 22 00:40:57 2009  vdc_3/
       4096     Sep 11 12:54:10 2008  vdc_4/
     111096     Dec 20 04:40:17 2008  vpc.cap
          0     Feb 03 08:02:14 2009  vpc_hw_check_disable
      18166     Apr 03 03:24:22 2009  vpc_vss_apr02
      18223     Apr 02 22:40:57 2009  vss_vpc_apr2

Usage for bootflash://sup-remote
  873283584 bytes used
  936615936 bytes free
 1809899520 bytes total
N7010-1#

Configuration Files: Configuration Rollback

The configuration rollback feature enables you to take a snapshot, or checkpoint, of the Cisco NX-OS configuration and then reapply that configuration to your device at any point without having to reload the device. Rollback allows any authorized administrator to apply this checkpoint configuration without requiring expert knowledge of the features configured in the checkpoint.

You can create a checkpoint copy of the current running configuration at any time. Cisco NX-OS saves this checkpoint as an ASCII file that you can use to roll back the running configuration to the checkpoint configuration at a future time. You can create multiple checkpoints to save different versions of your running configuration.

When you roll back the running configuration, you can trigger the following rollback types:

  • Atomic: Implement the rollback only if no errors occur. This is the default rollback type.
  • Best-effort: Implement a rollback and skip any errors.
  • Stop-at-first-failure: Implement a rollback that stops if an error occurs.

When you are ready to roll back to a checkpoint configuration, you can view the changes that will be applied to your current running configuration before committing to the rollback operation. If an error occurs during the rollback operation, you can choose to cancel the operation or ignore the error and proceed with the rollback. If you cancel the operation, Cisco NX-OS provides a list of changes already applied before the error occurred. You need to clean up these changes manually.

Configuration rollback limitations are as follows:

  • Allowed to create up to ten checkpoint copies per VDC.
  • You are not allowed to apply a checkpoint file of one VDC into another VDC.
  • You are not allowed to apply a checkpoint configuration in a nondefault VDC if there is a change in the global configuration portion of the running configuration compared to the checkpoint configuration.
  • The checkpoint filenames must be 75 characters or less.
  • You are not allowed to start a checkpoint filename with the word auto.
  • You cannot name a checkpoint file with summary or any abbreviation of the word summary.
  • Only one user can perform a checkpoint, rollback, or copy the running configuration to the startup configuration at the same time in a VDC.
  • After execution of write erase and reload commands, checkpoints are deleted. You can use the clear checkpoint database command to clear out all checkpoint files.
  • Rollback fails for NetFlow if during rollback you try to modify a record that is programmed in the hardware.
  • Although rollback is not supported for checkpoints across software versions, users can perform rollback at their own discretion and can use the best-effort mode to recover from errors.
  • When checkpoints are created on bootflash, differences with the running-system configuration cannot be performed before performing the rollback, and the system reports "No Changes."

Example 1-10 demonstrates how to create a configuration rollback.

Example 1-10. Creating a Configuration Rollback

N7010-1# checkpoint changes
...........Done
N7010-1# show diff rollback-patch checkpoint changes running-config
Collecting Running-Config
Generating Rollback Patch
Rollback Patch is Empty
N7010-1# conf t
Enter configuration commands, one per line. End with CNTL/Z.
N7010-1(config)# no snmp-server user nxos-admin
N7010-1(config)# exit
N7010-1# show diff rollback-patch checkpoint changes running-config
Collecting Running-Config
Generating Rollback Patch
!!
no username nxos-admin sshkey ssh-rsa
AAAAB3NzaC1yc2EAAAABIwAAAQEA6+TdX+ABH/mq1gQbfhhsjBmm65ksgfQb3Mb3qbwUbNlcAa6fjJCGdHu
f3kJ
ox/hjgPDChJOd-
kUXHjESlV59OhZP/NHlBrBq0TGRr+hfdAssD3wG5oPkywgM4+bR/ssCzoj6jVG41tGmfPip4pr3dqsMzR21
DXSK
K/tdj7bipWKy1wSkYQzZwatIVPIXRqTJY7L9a+JqVIJEA0QlJM1l0wZ5YbxccB2GKNKCM2x2BZl4okVgl80
CCJg
7vmn+8RqIOQ5jNAPNeb9kFw9nsPj/r5xFC1RcSKeQbdYAjItU6cX1TslRnKjlWewCgIa26dEaGdawMVuftg
u0uM
97VCOxZPQ==
no username nxos-admin
N7010-1# rollback running-config checkpoint changes
Note: Applying config in parallel may fail Rollback verification
Collecting Running-Config
Generating Rollback Patch
Executing Rollback Patch
Generating Running-config for verification
Generating Patch for verification
N7010-1# show snmp user nxos-admin
______________________________________________________________
                  SNMP USER
______________________________________________________________

User                          Auth  Priv(enforce) Groups
____                          ____  _____________ ______
nxos-admin                    sha   des(no)       network-operator

You can also enable specific SNMP traps:
N7010-1(config)# snmp-server enable traps eigrp
N7010-1(config)# snmp-server enable traps callhome
N7010-1(config)# snmp-server enable traps link
N7010-1(config)# exit
N7010-1#

Operating System Files

Cisco NX-OS Software consists of three images:

  • The kickstart image, contains the Linux kernel, basic drivers, and initial file system.
  • The system image contains the system software, infrastructure, Layers 4 through 7.
  • The Erasable Programmable Logic Device (EPLD) image: EPLDs are found on the Nexus 7000 currently shipping I/O modules. EPLD images are not released frequently,\; even if an EPLD image is released, the network administrator is not forced to upgrade to the new image. EPLD image upgrades for I/O modules disrupt traffic going through the I/O module. The I/O module powers down briefly during the upgrade. The EPLD image upgrades are performed one module at a time.

On the Nexus 7000 with dual-supervisor modules installed, NX-OS supports in-service software upgrades (ISSU). NX-OS ISSU upgrades are performed without disrupting data traffic. If the upgrade requires EPLD to be installed onto the line cards that causes a disruption of data traffic, the NX-OS software warns you before proceeding so that you can stop the upgrade and reschedule it to a time that minimizes the impact on your network.

NX-OS ISSU updates the following images:

  • Kickstart image
  • System image
  • Supervisor module BIOS
  • Data module image
  • Data module BIOS
  • Connectivity management processor (CMP) image
  • CMP BIOS

The ISSU process performs a certain sequence of events, as outlined here:

  1. Step 1. Upgrade the BIOS on the active and standby supervisor modules and the line cards (data cards/nonsupervisor modules).
  2. Step 2. Bring up the standby supervisor module with the new kickstart and system images.
  3. Step 3. Switch over from the active supervisor module to the upgraded standby supervisor module.
  4. Step 4. Bring up the old active supervisor module with the new kickstart image and the new system image.
  5. Step 5. Upgrade the CMP on both supervisor modules.
  6. Step 6. Perform nondisruptive image upgrade for line card (data cards/nonsupervisor modules), one at a time.
  7. Step 7. ISSU upgrade is complete.
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