RDO quickstart

Tonight I installed OpenStack with RDO Quickstart on RHEL6. They've really made it easy.

rhel7 beta ifconfig is gone; now what?

My minimally installed rhel7 beta system didn't include ifconfig.

[root@rhel7 ~]# ifconfig 
-bash: ifconfig: command not found
[root@rhel7 ~]# 

You can get it with the net-tools package:

yum install net-tools

but the Networking Guide makes no mention of it and seems to encourage nmcli. If you need to get your system online quickly and are unable to get net-tools installed here's a nmcli crash course.

Edit /etc/sysconfig/network-scripts/ifcfg-ethX, like usual, and bring the device up with:

nmcli con up eth0

or bring it down with:

nmcli con down eth0

You can go as short as "nmcli c u eth0" or as long as "nmcli connection up eth0".

To see your active connections:

nmcli c s a

or do the long version:

[root@rhel7 ~]# nmcli connection show active
NAME  UUID                                  DEVICES  DEFAULT  VPN  MASTER-PATH 
eth0  5a26138b-99c5-4769-a036-7856598e696e  eth0     yes      no   --          
[root@rhel7 ~]# 

To then zoom in on the details of one of the devices see:

nmcli d sh eth0

or again do the long version and you'll get a lot more info:

[root@rhel7 ~]# nmcli device show eth0 | wc -l
55
[root@rhel7 ~]# 

So you might want to grep for just the IP or Mac:

[root@rhel7 ~]# nmcli d sh eth0 | grep ip
IP4.ADDRESS[1]:                         ip = 192.168.122.70/24, gw = 192.168.122.1
DHCP4.OPTION[6]:                        ip_address = 192.168.122.70
IP6.ADDRESS[1]:                         ip = fe80::5054:ff:fe5f:edfa/64, gw = ::
[root@rhel7 ~]# 

[root@rhel7 ~]# nmcli d sh eth0 | grep -i hw
GENERAL.HWADDR:                         52:54:00:5F:ED:FA
[root@rhel7 ~]# 

For bonus points, set your hostname using hostnamectl.

hostnamectl set-hostname $hostname

But don't forget to edit /etc/hosts.

The Slab

Today I learned about memory management via slab allocation and slabtop along with the move to slub after 2.6.23.