Cisco Catalyst: Configure a Trunk Port with a Native Vlan

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This post will show you how to configure a trunk port with a native vlan. In this specific example I am configuring a range of ports, but the commands for an individual interface will be the same once you have entered the config for a particular port.

First enter configuration mode

s3560#conf terminal

Now we configure the range of ports. Here we are configuring the range of ports to be a trunk, using dot1q encapsulation. We are allowing vlans 96-99, and vlan 101. We are also setting vlan101 to be the native vlan (no vlan tagging required).

s3560(config)#interface range gigabitEthernet 0/13 – 24
s3560(config-if-range)#description generic trunk ports
s3560(config-if-range)#switchport trunk encapsulation dot1q
s3560(config-if-range)#switchport mode trunk
s3560(config-if-range)#switchport trunk native vlan 101
s3560(config-if-range)switchport trunk allowed vlan 96-99,101

Now we enable spanning-tree portfast and bpduguard

s3560(config-if-range)#spanning-tree portfast

%Warning: portfast should only be enabled on ports connected to a single
host. Connecting hubs, concentrators, switches, bridges, etc… to this
interface when portfast is enabled, can cause temporary bridging loops.
Use with CAUTION

%Portfast will be configured in 13 interfaces due to the range command
but will only have effect when the interfaces are in a non-trunking mode.

s3560(config-if-range)#spanning-tree bpduguard enable
s3560(config-if-range)#end

Save your config changes

s3560#copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
0 bytes copied in 1.443 secs (0 bytes/sec)
s3560#

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Cisco Catalyst: Reset/Clear Port Config

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Reset Port Config to Default for One Port

Use the command below to clear the configuration on a port.

s3560(config)#default interface gigabitEthernet 0/3
Interface GigabitEthernet0/3 set to default configuration

Use the command below to verify that the running config for the port has been reset to the default configuration.

s3560#show running-config interface gigabitEthernet0/3
Building configuration…

Current configuration : 36 bytes
!
interface GigabitEthernet0/3
end

Now write your changes to memory.

s3560#copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
0 bytes copied in 1.427 secs (0 bytes/sec)

Reset Port Config to Default for a Range of Ports

Below we are going to clear/delete the config from a range of ports

s3560#conf terminal

s3560(config)#default interface range gigabitEthernet 0/13 – 24

Again, don’t forget to save your changes.

 

 

OpenStack: 9 tips to properly configure your OpenStack Instances

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Qcow vs Raw, Performance Tweaks, Cloud-init, and a short guide on Kernel Tuning – courtesy of redhatstackblog.redhat.com

via 9 tips to properly configure your OpenStack Instance

OpenStack: Deleting Zombie Cinder Volumes and VMs

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First off let me start by saying that the new Cinder logo is wonderful. Nothing helps me think of backend storage better than the backend of a horse.

In an environment I am working in, we have a large number of cinder volumes that are in error state, due to the backend storage being ripped out. The volumes were not deleted, nor were they detached from the VMs.

End result, you cannot delete the zombie VM (at it has an attached volume) and you cannot delete the zombie/orphaned volume (as it is attached to a VM).

The following process allows you to work around the chicken-and-egg scenario above.

First we get a list of all volumes in error state.

# openstack volume list –all | grep -i error

Then we take a closer look at the volume to see if it exists/existed on the backend that was removed.

# openstack volume show 05b372ef-ee45-499b-9676-72cc4170e1b3

First we check the backend to ensure it is the affected backend – in this case it is.

| os-vol-host-attr:host | hostgroup@dellsc#openstack_dellsc

We also check for any current attachments. Below we see that this volume is attached to a vm with the uuid shown below.

| attachments | [{u’server_id’: u’d142eb4b-823d-4abd-95a0-3b02a3194c9f’,

Now we reset the state of the volume, so that it is no longer in an error state

# cinder reset-state –state available 05b372ef-ee45-499b-9676-72cc4170e1b3

Now we detach the volume via cinder.

# cinder reset-state –attach-status detached 05b372ef-ee45-499b-9676-72cc4170e1b3

Now we are free to delete the volume

# openstack volume delete 05b372ef-ee45-499b-9676-72cc4170e1b3

Confirm volume deletion

# openstack volume show 05b372ef-ee45-499b-9676-72cc4170e1b3
No volume with a name or ID of ’05b372ef-ee45-499b-9676-72cc4170e1b3′ exists

Now we can delete the VM.

# openstack server delete d142eb4b-823d-4abd-95a0-3b02a3194c9f

And now we confirm its deletion.

#openstack server show d142eb4b-823d-4abd-95a0-3b02a3194c9f
No server with a name or ID of ‘d142eb4b-823d-4abd-95a0-3b02a3194c9f’ exists.

OpenStack: Mapping Ironic Hostnames to Nova Hostnames

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The Hostname Problem

When deploying OpenStack via Red Hat OSP director you configure the hostname of your baremetal (ironic) nodes at time of import. This is done via json file, by default named instack-env.json (but often re-named, nodes.json). Below is an excerpt from that file.

{
“nodes” :  [
{
“arch”: “x86_64”,
“cpu”: “4”,
“disk”: “40”,
“mac”: [
“58:8a:5a:e6:c0:40”
],
“memory”: “6144”,
“name”: “fatmin-ctrl0”,
“pm_addr”: “10.10.1.100”,
“pm_password”: “Mix-A-Lot”,
“pm_type”: “pxe_ipmitool”,
“pm_user”: “sir”
}

 

In the sample instance above, I am importing a node named, “fatmin-ctrl01”. This will be the server name as it appears in Ironic.  When heat deploys the overcloud, this node will by default be renamed overcloud-controller0, and any controller nodes will iterate by 1. Same situation for compute nodes.

What is preferable is to configure what is referred to as “Predictable Hostnames”. Using “Predictable Hostnames” we can do one of two things.

  1. Specify the hostname format to use and allow nova to iterate through nodes on its own.
  2. Specify the exact hostname for nova to use for each baremetal node

Nova Scheduler Hints

Before we can use either of the two options above, we must first update each baremetal node with a nova scheduler hint. In the examples below we are tagging one node to build as controller-0 (overcloud-controller0) and one node to build as (overcloud-compute-0).

For Controllers: Repeat for each controller

# ironic node-update <id> replace properties/capabilities=”node:controller-0,boot_option:local”

For Compute Node: Repeat for each compute node

# ironic node-update <id> replace properties/capabilities=”node:compute-0,boot_option:local”

You will then need to set your nova hints

parameter_defaults:
ControllerSchedulerHints:
‘capabilities:node’: ‘controller-%index%’
ComputeSchedulerHints:
‘capabilities:node’: ‘compute-%index%’

FYI – the same process can be used for the following hostname types

  • ControllerSchedulerHints
  • ComputeSchedulerHints
  • BlockStorageSchedulerHints
  • ObjectStorageSchedulerHints
  • CephStorageSchedulerHints

Custom Nova Hostname Format

Referring to option 1 shown above, we can set a specific format to be used for hostnames instead of the default.

 ControllerHostnameFormat: ‘fatmin-controller-%index%’
ComputeHostnameFormat: ‘fatmin-compute-%index%’

Using the method above the first compute node will be names fatmin-controller-01, and the first compute node will be names fatmin-compute-01. Additional nodes will iterate the index.

While this is nice, as it allows us to set a customized hostname format  for each type of node, it does not allow us to specify the exact hostname to be used for a specific ironic node.  We can do that will the HostnameMap.

HostnameMap

Now you may want to take this a bit further. You may want to use a custom nova name for each node compute/controller node. You can accomplish this using a HostnameMap as shown below.

HostnameMap:
overcloud-controller-0: fatmin-controller-0
overcloud-controller-1: fatmin-controller-1
overcloud-controller-2: fatmin-controller-2
overcloud-compute-0: fatmin-compute-0

 

Note, when specifying the flavor profiles in the deploy command for preassigned nodes, they should be specified as ‘baremetal‘ instead of ‘control‘ and ‘compute‘. This means that you will not have to assign a profile to each host. You will let the nova scheduler hints handle the decision

–control-flavor baremetal \
–compute-flavor baremetal \

So at this point – we will be able to allign the compute or controller index in ironic, with the index in Ironic. For example you can now map your ironic-node name (for example) fatmin-ctrl0 to fatmin-controller0.

Special Notes for Special People

  1. I do not suggest setting the nova name to the exactly the same name that you defined for the ironic name. While the indexes should match, the name formats should vary enough that you can easily tell if you are looking at a nova name or an ironic name.
  2. The use of HostnameMap will easily facilitate the replacement of a failed node so that you can provision the new node with the same nova name that was used by the original node before its premature death. Otherwise, nova will blacklist the nova name of the failed node. For example if controller0 dies and you need to replace and redeploy it, it will end up being named controller4 since this is the next number in the index.