Show Tech on NX-OS

[Carlos Victorino]

When we run show tech on our NX-OS device it generates a ridiculously large file (over 300MB before we kill the process).

The culprit being the 'show system internal biosd messages'.

When we remove that section it goes from a 300+MB file to 1MB.

With that being said is there a way to run show tech while excluding sections?

Or run a Show Tech and only include sections that we need?

Please advise

[MHM Cisco World]

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/7-x/command_references/show_commands/b_Using_Show_Commands/b_Using_Show_Commands_chapter_010011.html

this command reference is for show tech ...... 

[Carlos Victorino]

Yes I had seen that link but it didnt answer my question in regards to excluding sections.

Additionally I was trying to figure out if we could possibly run a show tech with only sections that we need in a single command 

For Ex:

show tech-support arp, bfd, bgp ...

[MHM Cisco World]

I test command and I see 
show tech-support with 
> to file (to file I think is better for your case you can send show tech-support to file and then read it)
brief 
| include..exclude ....etc. 

so I see all these option, 
but show tech-support is for cisco TAC, some info. appear can not full understand. 

[Christopher Hart · Accepted solution]

Hi Carlos!

The output of show tech-support and show tech-support details on Cisco Nexus switches can be quite large depending upon a variety of factors, including:

• The uptime of the switch
• The features (and quantity of features) configured on the switch
• Whether the switch has a fixed form factor (e.g. top-of-rack Nexus 9300 switches) or is a modular switch (e.g. end-of-row Nexus 9500 series switches)
• The amount of network activity and general entropy on the switch (control plane protocol churn, churn in the data plane [such as MAC addresses moving between interfaces], interface flap activity, etc.)

The output of show tech-support on Nexus switches is technically an alias for the show tech-support brief command, so I would not expect it contain nearly the same amount of information as the output of show tech-support details. With that being said, very large show tech-support output can be expected on Nexus switches - I have seen them range from as "small" as 100 megabytes to as large as ~2.5 gigabytes (in the case of a fully-loaded Nexus 9508 or 9516 chassis with a long uptime in a very active network). When written to the bootflash of the switch (which is the most efficient method of gathering this output), the show tech-support details can take anywhere from ~5 minutes to ~60 minutes to complete, depending on the aforementioned factors.

To directly answer your question, you cannot filter out a specific command or set of commands from within a show tech-support command. To use your example, you cannot execute the show tech-support command, but "skip" the show system internal biosd messages command. However, on Nexus switches, you can gather feature-specific data through the show tech-support <feature> command, wherein <feature> is the name of the feature you'd like to gather information about. For example, if you'd like to troubleshoot an OSPF issue, the output of show tech-support ospf is what you most likely want to gather. A generic IPv4 routing issue can be troubleshot through the output of show tech-support ipv4 unicast.

You can see the full list of show tech-support commands you can execute through the context-sensitive help of the command line interface by typing show tech-support ?. An example of this from a switch in my lab is shown below.

switch# show tech-support ?
                      
  >                       Redirect it to a file
  >>                      Redirect it to a file in append mode
  aaa                     Display aaa information
  aclmgr                  ACL commands
  aclqos                  Show information for aclqos technical support
  adjmgr                  Display Adjmgr information
  all                     Gather detailed information for troubleshooting
  arp                     Display ARP information
  ascii-cfg               Show ascii-cfg information for technical support personnel
  bfd                     BFD commands
  bgp                     Display BGP status and configuration
  biosd                   Gather bios install log for trouble shooting
  bloggerd                Gather detailed information for bloggerd troubleshooting
  bloggerd-all            Gather detailed information for bloggerd troubleshooting from ALL modules
  bootvar                 Gather detailed information for bootvar troubleshooting
  brief                   Gather summary information for troubleshooting
  callhome                Callhome troubleshooting information
  cdp                     Gather information for CDP trouble shooting
  cert-enroll             Display certificates information
  cfs                     Gather detailed information for cfs troubleshooting
  cli                     Gather information for parser troubleshooting
  clis                    Gather information for CLI Server troubleshooting
  clock_manager           Gather detailed information for clock manager troubleshooting
  commands                Show commands executed as part of show tech-support commands
  config-profile          Gather information for troubleshooting config-profiles
  copp                    Gather information for copp trouble shooting
  cores                   Debugging information for process crashes
  dcbx                    Gather detailed information for DCBX component
  details                 Gather detailed information for troubleshooting
  dhclient                Gather information for dhclient trouble shooting
  dhcp                    Gather detailed information for dhcp troubleshooting
  dme                     Gather detailed information for dme troubleshooting
  ecp                     ECP (Edge Control Protocol)
  eem                     Show EEM tech-support information
  eltm                    Eltm debug info
  epp                     Gather detailed information for EPP troubleshooting
  ethpm                   Gather detailed information for ETHPM troubleshooting
  fabric                  Fabric
  fc                      Get fibre channel related information
  fc2                     Show information for fc2 technical support
  feature                 Gather detailed information for feature troubleshooting
  fib                     Gather detailed information for FC/FCoE FIB troubleshooting
  fib-all                 Gather detailed information for FC/FCoE FIB from all modules
  fips                    Show tech support information for security
  forwarding              Forwarding debug info
  frequency               Gather detailed information for frequency synchronization troubleshooting
  gold                    Show gold tech-support information
  gpixm                   Gather detailed information for GLOBAL-PIXM troubleshooting
  ha                      Gather detailed information for HA troubleshooting
  ha_short                Gather shortened version of HA tech-support for troubleshooting
  icam                    Icam - TCAM Analytics
  icmpv6                  Display Icmpv6 information
  im                      Gather detailed information for IM troubleshooting
  inband                  Gather all information about inband data path
  include-time            Gather tech-support and capture time taken to execute each command
  install                 Gather detailed information for rpm/package install operation
  interface-vlan          Gather detailed information for interface-vlan troubleshooting
  interfaces (no abbrev)  Gather information for interfaces troubleshooting
  internal                Gather internal info for troubleshooting
  intersight              Intersight tech support
  ip                      Display IP information
  ipqos                   IP QoS Manager
  ipv4                    Display IP information
  ipv6                    Display IPv6 information
  issu                    Gather detailed information for issu troubleshooting
  kstack                  Kstack information
  l2                      Gather detailed information for layer 2 troubleshooting
  l2fm                    L2fm debug info
  l2pt                    Gather information for l2pt troubleshooting
  l2rib                   Display L2RIB information
  l3vm                    Display VRF information
  lacp                    Gather detailed information for LACP component
  license                 Display licensing information
  lim                     Gather detailed information for LIM troubleshooting
  lldp                    Gather detailed information for LLDP troubleshooting
  logging                 Show information on logging for technical support staff
  m2rib                   Gather detailed information for M2RIB troubleshooting
  macsec                  Macsec debug info
  memory                  Gather detailed information of memory for Kernal debugging
  mfwd                    Display MCASTFWD status and configuration
  mmode                   Gather information for troubleshooting mmode
  module                  Gather info related to a module
  monitor                 Gather detailed information for monitor troubleshooting
  monitorc-all            Gather detailed information for LC MONITORC troubleshooting
  mpls                    MPLS
  mplsfwd                 Display MPLS forwarding information
  multicast               Display V4 Multicast information
  multicast-vxlan-evpn    Multicast VxLAN EVPN feature
  netstack                Gather information for NETSTACK troubleshooting
  ngoam                   Ngoam
  nia                     NIA Element Python App
  npacl                   Display npacl information
  ns                      Gather detailed information for northstar asic
  ntp                     Gather information for NTP trouble shooting
  nve                     Display NVE information
  nxapi                   Gather detailed information for nxapi troubleshooting
  ofm                     Overlay Flow Manager
  openflow                Openflow component
  ospf                    Display OSPF status and configuration
  page                    Page through the output
  patch                   Gather detailed information for patch troubleshooting
  pfstat                  Gather detailed information for pfstat troubleshooting
  pie                     Gather detailed information of feature pie debugging
  pixm                    Gather detailed information for vdc-local-PIXM troubleshooting
  pixm-all                Gather detailed information for PIXM troubleshooting
  pixmc-all               Gather detailed information for LC PIXMC troubleshooting
  pktmgr                  Display Packet Manager information
  platform-sdk            Gather detailed information for platform-sdk troubleshooting
  plcmgr                  Policy Manager
  pltfm-config            Gather detailed information for pltfm-config troubleshooting
  pnp                     Show Technical support for Plug and Play
  poap                    Gather detailed information for poap troubleshooting
  poe                     Gather information for PoE trouble shooting
  port                    Gather detailed information for port manager troubleshooting
  port-channel            Gather detailed information for port channel troubleshooting
  port-client-all         Gather detailed information for LC port client troubleshooting
  port-profile            Gather information for troubleshooting port-profiles
  pss                     Gather detailed information for PSS troubleshooting
  ptp                     Gather detailed information for PTP troubleshooting
  radius                  Display radius information
  routing                 Display routing information
  rpm                     Display Route Policy Manager (RPM) information
  sal                     Show SAL tech-support information
  san-port-channel        Gather detailed information for san port channel troubleshooting
  satmgr                  Gather detailed information for satmgr troubleshooting
  security                Show tech support information for security
  session-mgr             Gather information for troubleshooting session manager
  sflow                   Gather detailed information for sflow feature
  sksd                    Show tech support information for sksd
  slowdrain               Gather detailed information for slowdrain troubleshooting
  smm                     Shared memory
  snmp                    Gather info related to snmp
  sockets                 Display sockets status and configuration
  spm                     Service Policy Manager
  statsclient             Gather statsclient tech-support
  stp                     Gather detailed information for STP troubleshooting
  sup-filesys             File-sys related issue
  super-bridging          Gather detailed information for super-bridging troubleshooting
  sysmgr                  Gather detailed information for sysmgr troubleshooting
  time-optimized          Gather tech-support faster, requires more memory & disk space
  track                   Show track tech-support information
  trm-pd                  TRM platform components
  tunnel                  Gather detailed information for tunnel troubleshooting
  udld                    Gather detailed information for udld troubleshooting
  usd-all                 Gather detailed information for LC USD troubleshooting
  vdc                     Gather detailed information for VDC troubleshooting
  virtual-service         Gather information for virtualization services trouble shooting
  vlan                    Gather detailed information for VLAN troubleshooting
  vpc                     Gather detailed information for VPC troubleshooting
  vshd                    Show vshd information for technical support
  vvlan                   Gather detailed information for Voice VLAN troubleshooting
  vxlan                   VxLAN components
  vxlan-evpn              VxLAN evpn feature
  xbar                    Show xbar tech-support information
  xml                     Gather information for xml trouble shooting
  xos                     Cross-OS Library Information and Traces
  |                       Pipe command output to filter

 I hope this helps - thank you!

-Christopher

[MHM Cisco World]

more info about this case 

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/93x/troubleshooting/guide/b-cisco-nexus-9000-nx-os-troubleshooting-guide-93x/b-cisco-nexus-9000-nx-os-troubleshooting-guide-93x_chapter_010000.html