Monthly Archives: September 2018

“x/xx on FI-A is connected by a unknown server device” on Cisco UCS

You may see following errors in ‘info’ category of error messages in the Cisco UCS Manager after upgrading infrastructure firmware to 3.2.x.

“x/xx on FI-A is connected by a unknown server device”

This is bug documented in CSCvk76095. You have to reset the port on FI to fix it.

  1. Go to “Equipment” in Cisco UCS Manager.
  2. Go to “Fabric Interconnects” -> Go to the corresponding FI.
  3. Right-click the port x/xx -> Choose “Disable“.
  4. You will see multiple major faults. Wait for 5 seconds.
  5. Right click the port x/xx -> Choose “Enable“.
  6. All warnings disappeared after 5 mins. You may still see the warning in GUI due to cache. Relogin and check.

This change impacts to one link between IOM and the FI port. You need downtime if the IOM only has a single path. I don’t see any impact to ESXi blades in the pod.

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“The update is not applicable to your computer” When Install Standalone Patch on Windows Server 2016

You may see error message below when installing standalone patches on Windows Server 2016.

The update is not applicable to your computer

2018-09-29 14_50_07-Windows Server 2016 GUI - VMware Workstation

It may be caused be servicing stack update is not installed on the server. Please install KB4132216 before installing the patch.

Connect to New Provisioned Raspberry Pi Less than $3

The IP configuration of new provisoined Raspberry Pi struggled me a long time. I need to connect to a monitor so I login to system and configure IP address. The problem was I don’t have monitor. I only have a laptop.

Last year, my old laptop dead. I connected the laptop monitor to a HDMI board to my Raspberry Pi. It’s not a low cost solution, it costed me more than $10. And the monitor, cables and board looks uglily.

IMG_1844

Actually there is another solution to leveraging laptop keyboard and monitor. It’s serials port to console. Something similar like when you configure Cisco network switches. Following is how to do it. I achieve that on Raspberry Pi 2.

  1. You need to buy a USB to TTL device with chipset CP2102.
  2. Connect the pins to Raspberry Pi 2. Refer here for GPIO layout.
    TXD > Pi RXD Pin #10 (GPIO 16)
    RXD > Pi TXD Pin #08 (GPIO 15)
    GND > Pi GND Pin #6
  3. Connect the USB to laptop. You will see a device in ‘Device Manager’ needs drivers.
  4. Download driver and install.
  5. Download Putty and install.
  6. Open Putty and “Serial”.
  7. “Serial line” is COM3 or COM4.
  8. “Speed” is 115200.

The USB to TTL I bought on Taobao (Chinese version of Aliexpress). It’s around $1.2 including shipping.

Show CDP Neighbor of Cisco UCS Uplinks

There are two ways to know which network switch ports the network uplinks of Cisco UCS Fabric Interconnects are connected to.

By CLI

  • SSH to the Cisco UCS Manager.
  • Connect to FI-A.
# connect nxos a
  • Show neighbor of network uplinks.
# show cdp neighbor interface ethernet <port num>

By PowerShell

  • Make sure Cisco PowerTool (For UCS Manager) is installed.
  • Enabling the Information Policy via UCSM GUI.
    • Go to “Equipment” -> “Policies” tab -> “Global Policies” tab -> “Info Policy” area.
    • Change to “Enabled“. (No impact to running blades)
  • Open a PowerShell window.
  • Connect to the UCS Manager.
# Connect-Ucs <UCS FQDN>
  • Show CDP neighbor details.
# Get-UcsNetworkLanNeighborEntry

Side notes

Following command can shows network switch name, network switch ports and FI ports

# Get-UcsNetworkLanNeighborEntry | Select deviceid,remoteinterface,localinterface

If you prefer to enable the “Info Policy” by PowerShell, run following command

# Get-UcsTopInfoPolicy | Set-UcsTopInfoPolicy -State enabled -Force

“default Keyring’s certificate is invalid” in Cisco UCS Manager

You may see following error in Cisco UCS Manager:

default Keyring’s certificate is invalid

The reason is Admin -> Key Management -> KeyRing default is expired. It’s not possible to delete or change the KeyRing in GUI. You have to log in to SSH of Cisco UCS Manager and run following commands (The strings after “#”):

lab-B# scope security
lab-B /security # scope keyring default
lab-B /security/keyring # set regenerate yes
lab-B /security/keyring* # commit-buffer
lab-B /security/keyring #

This will result in a disconnect of the Cisco UCS Manager GUI on your client computer. Just refreshing the page after 5 seconds. It’s no impact to blades.

A Huge Amount of Warnings of “Image is Deleted” in Cisco UCS Manager

A few days ago, I deleted some older firmware packages in Cisco UCS Manager. Suddenly more than 100 warnings were generated. The error messages are similar below:

blade-controller image with vendor Cisco System Inc……is deleted

Cause: image-deleted

Clearly, it’s triggered due to packages deletion. But all of my service profiles and service profile templates were using existing firmware packages. The deleted packages were not been used anywhere.

I also deleted download tasks and cleaned up everything I can. The warnings still persisted. I figured out it’s caused by the default firmware policy when I read a blog article.

In case you are facing same issue. Please go to Servers -> Policies -> Host Firmware Packages -> default ->  Click Modify Package Versions -> Change it to available version.

 

Install LXC on CentOS 7 Minimal Version

Some notes for LXC. CentOS 7 minimal version doesn’t support LXC installation by default since LXC is deprecated in version 7. The new container solution is based on docker framework.

There is an alternative to install LXC. Following are procedures:

  1. Install Epel (Extra Packages for Enterprise Linux) repository.
    # yum install epel-release
  2. Install some dependencies.
    # yum install perl debootstrap libvirt
  3. Now you can install LXC in the epel repository.
    # yum install lxc lxc-template