Tag: systemd

Renaming a network interface with systemd-networkd on Ubuntu 18.04

On a Ubuntu system where I’m creating a VXLAN Proof of Concept with CloudStack I wanted to rename the interface enp5s0 to cloudbr0.

I found many documentation on the internet on how to do this with *.link files, but I was missing the golden tip, which was you need to re-generate your initramfs.

/etc/systemd/network/50-cloudbr0.link

[Match]
MACAddress=00:25:90:4b:81:54

[Link]
Name=cloudbr0

After you create this file, re-generate your initramfs:

update-initramfs -c -k all

You can now use cloudbr0 in *.network files to use it like any other network interface.

In my case this is how my interfaces look like:

1: lo:  mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
6: cloudbr0:  mtu 9000 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:25:90:4b:81:54 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.11/24 brd 192.168.0.255 scope global cloudbr0
       valid_lft forever preferred_lft forever
    inet6 2a00:f10:114:0:225:90ff:fe4b:8154/64 scope global dynamic mngtmpaddr noprefixroute 
       valid_lft 2591993sec preferred_lft 604793sec
    inet6 fe80::225:90ff:fe4b:8154/64 scope link 
       valid_lft forever preferred_lft forever
8: cloudbr1:  mtu 1450 qdisc noqueue state UP group default qlen 1000
    link/ether 86:fa:b6:31:6e:c1 brd ff:ff:ff:ff:ff:ff
    inet 172.16.0.11/24 brd 172.16.0.255 scope global cloudbr1
       valid_lft forever preferred_lft forever
    inet6 fe80::84fa:b6ff:fe31:6ec1/64 scope link 
       valid_lft forever preferred_lft forever
9: vxlan100:  mtu 1450 qdisc noqueue master cloudbr1 state UNKNOWN group default qlen 1000
    link/ether 56:df:29:8d:db:83 brd ff:ff:ff:ff:ff:ff

Using the new dashboard in ceph-mgr

The upcoming Ceph Luminous (12.2.0) release features the new ceph-mgr daemon which has a few default plugins. One of these plugins is a dashboard to give you a graphical overview of your cluster.

Enabling Module

To enable the dashboard you have to enable the module in your /etc/ceph/ceph.conf on all machines running the ceph-mgr daemon. These are usually your Monitors.

Add this to the configuration:

[mgr]
mgr_modules = dashboard

Don’t restart your ceph-mgr daemon yet. More configuration changes have to be made first.

Setting server address and port

A server address and optionally a port have to be configured as a config-key.

By setting the value to :: the dashboard will be available on all IPv4 and IPv6 addresses on port 7000 (default):

ceph config-key put mgr/dashboard/server_addr ::

Restart daemons

Now restart all ceph-mgr daemons on your hosts:

systemctl restart ceph-mgr@

Accessing the dashboard

The default port is 7000, so now go to the IP-Address of the active ceph-mgr and open the see the dashboard.

You can find the active ceph-mgr in the ceph status:

root@alpha:~# ceph -s
  cluster:
    id:     30d838cd-955f-42e5-bddb-5609e1c880f8
    health: HEALTH_OK
 
  services:
    mon: 3 daemons, quorum alpha,bravo,charlie
    mgr: charlie(active), standbys: alpha, bravo
    osd: 3 osds: 3 up, 3 in
 
  data:
    pools:   1 pools, 64 pgs
    objects: 0 objects, 0 bytes
    usage:   3173 MB used, 27243 MB / 30416 MB avail
    pgs:     64 active+clean
 
root@alpha:~#

In this case charlie is the active mgr which in my case has IPv6 Address 2001:db8::102.

Point your browser to: http://[2001:db8::102]:7000 and you will see the dashboard.