How to cleanup your /boot in Ubuntu

First check your kernel version, so you won’t delete the in-use kernel image, running:

uname -a

Now run this command for a list of installed kernels:

sudo dpkg --list 'linux-image*'

and delete the kernels you don’t want/need anymore by running this:

sudo apt-get remove linux-image-VERSION linux-image-VERSION

Replace VERSION with the version of the kernel you want to remove.

When you’re done removing the older kernels, you can run this to remove ever packages you won’t need anymore:

sudo apt-get autoremove

And finally you can run this to update grub kernel list:

sudo update-grub

Ubuntu set local hostname via DHCP

Sometime for automation you need to be able to set the ubuntu hostname at  boot ( or at network restart ) via DHCP / DNS .

To be able to do that you only have to add in /etc/dhcp/dhclient-exit-hooks.d a file named hostname with the following content:

 

if [ "$reason" != BOUND ] && [ "$reason" != RENEW ] \
&& [ "$reason" != REBIND ] && [ "$reason" != REBOOT ]
then
return
fi

host=$(host $new_ip_address | cut -d ' ' -f 5)
host=${hostname:0:-1}
echo $host > /etc/hostname
hostname $host

What it does ? Simple it hooks dhcpclient and after the client receives the new ip from dhcp it will make a simple reverse lookup for the ip received
and will set the hostname accordingly.

How to store git password in config and allow automatisations

One of the best git commands i found so far is the following:

git config credential.helper store

This way git doesn’t ask anymore for user / pass when you try to push / pull from a repository givind us the posibility to automate things. Automate code pushing to servers . Automatic folder sincronisations with a git repo and much more .

Synology wake it up on LAN

Synology like any other recent and decent device accepts WakeOnLan . This comes very handy when you don’t want to keep it always on .
Setting synology is pretty easy . Just go to control panel , on Hardware and Power menu from the synology web interface and check Enable WOL on LAN1
wol-synology

However in order to wake it up you need to send in the network the magic packet to wake it.

I found that etherwake does the job right. Since i have eth1 connected to the internal network i’m using it like this:


etherwake -i eth1 00:11:33:22:bb:aa

where 00:11:33:22:bb:aa is the mac address from synology network card.

Ubuntu 14.04 adding HP proliant support pack (hpacucli problem solved)

tfm_logoIn the begining there was nothing but few baremetal. After a while someone delivers a whole bunch of baremetal on your doorstep and say : “I need them installed by tomorrow”. Same configuration … With the harddisks in raid and ubuntu on all of them . What do you do ?

It’s a big problem. Like most big problems you split it in lots of little problems that can be managed easier.
What you need to do for one baremetal:

  1. Update the ILO firmware and Bios (if necessary) . This will come handy: https://play.google.com/store/apps/details?id=com.hp.essn.iss.ilo.iec.spa&feature=search_result . I’m not going into details about it in this post
  2. Create the disk arrays
  3. Install the operating system on it
  4.  Configure it and deploy it.

For one server let’s say you can do it in few hours , few beers and some pizza’s. But … wait a minute .. There are a LOT of baremetals to be installed. One option is to call some friends and do that while you watch a movie.

OR you can be smart and automate the tasks. How ? What i need ?

You need a baremetal installer server or a laptop or a virtual something (virtual box / vmware / you choose )  image that will do the job for you while you sit back and relax.

The ideea is simple:

  • Baremetal will boot from network
  • tftp server will deliver the boot image, boot it , get an ip addres from the dhcp server and register the new server into the baremetal installer and will fill the hardware configuration there.
  • Then you can ( using ansible  ) to actually do the raid configuration ,  bios updates ,  firmware updates, and operating system install.
  • Add the necessary configurations.
  • Once complete the system will boot from raid and you have a system up and and running ready to be deployed.

Now … Back to the post subject .

How you can configure HP raid from inside  ubuntu ? In order to have in the network bootable image the proper tools to do actually do the configurations…

First we install hpacucli :


sudo echo "deb http://downloads.linux.hp.com/SDR/downloads/MCP/ubuntu precise/current non-free" >>/etc/apt/sources.list
wget http://downloads.linux.hp.com/SDR/downloads/MCP/GPG-KEY-mcp
sudo apt-key add GPG-KEY-mcp
sudo apt-get update
apt-get install cpqacuxe hp-ams hp-health hpacucli hponcfg
service hpsmhd stop
update-rc.d hpsmhd disable
hpasmcli -s "show server"

Then when we boot the new baremetal to be installed we can gather the informations about the raids:


hpacucli ctrl all show config

That will produce an output like ( in this case i already configured the raid:


Smart Array E200i in Slot 0 (Embedded) (sn: VX9AMP1927 )

array A (SAS, Unused Space: 0 MB)

logicaldrive 1 (136.7 GB, RAID 1, OK)

physicaldrive 1I:1:1 (port 1I:box 1:bay 1, SAS, 146 GB, OK)
physicaldrive 1I:1:2 (port 1I:box 1:bay 2, SAS, 146 GB, OK)

At this point you can create some scripts that will create the partitions in the way that the shareholder wants them.

for example:


hpacucli ctrl slot=9 create type=logicaldrive drives=1I:1:3,1I:1:4 raid=1