Setting up a minimal Raspberrian on a Raspberry Pi2

by | Sep 4, 2016 | 0 comments

After resetting my previous installation of Observium on a Raspberry Pi I will move forward and install a LibreNMS instead. My first steps are:

  • Zapping the old installation
  • Downloading the
  • Installing that image
  • Booting the first time
  • Setting up initial networking
  • Updates
  • Installation of necessary toolset
  • Setup backup
  • Hook the system into my OpenVPN cloud
  • Setting up email sending and root mail forward
  • Getting SNMPd up and running
Zapping old installation

On my Mac I do:

sudo bash
diskutil list
# Use the correct disk or you delete your own installation
dd if=/dev/zero of=/dev/disk5 bs=1024k
Downloading image

Get your latest image of the Raspberian Lite here.

Installing the image
# See what we got and unpack it
shasum -a1 
# Compare with the SHA-1 on the website!!!
unzip -l 
  Length     Date   Time    Name
 --------    ----   ----    ----
1387266048  05-27-16 13:41   2016-05-27-raspbian-jessie-lite.img
 --------                   -------
1387266048                   1 file
  inflating: 2016-05-27-raspbian-jessie-lite.img  
-rw-r--r--@ 1 root  staff   1,3G 27 Mai 13:41 2016-05-27-raspbian-jessie-lite.img
# And now install it
dd if=2016-05-27-raspbian-jessie-lite.img of=/dev/disk5 bs=1024k
1323+0 records in
1323+0 records out
1387266048 bytes transferred in 529.211209 secs (2621384 bytes/sec)
First boot
Expand the filesystem

Expand the filesystem



Screen Shot 2016-09-04 at 12.01.56

Always boot on console

Always boot on console

Always set timezone to Etc/UTC

Always set timezone to Etc/UTC

The GPU does not need much

The GPU does not need much

Setting up initial network

As the system is setup to boot via DHCP, just give it a new name. I choose UniMatrixOne

sudo bash
aptitude update
aptitude safe-upgrade
aptitude clean
Installing necessary tools

I install my normal tool set and the part for borgbackup

aptitude install vim-nox htop screen tcpdump tshark iotop lvm2 rsync \
python3 python3-dev python3-pip python-virtualenv \
libssl-dev openssl \
libacl1-dev libacl1 \
liblz4-dev liblz4-1 \
pip3 install borgbackup
Setup Backup

I use borg backup on an external 3.5″ disk, which is hooked via SATA2USB Adapter.
To setup the backup disk I use lvm:

# I assume the disk is at /dev/sdb
# Add one primary partition and give it all the space
# as ext2
fdisk /dev/sdb
# Create the physical volume
pvcreate /dev/sdb1
# Create the volume group
vgcreate vg_backup /dev/sb1
# Create the logical volume
lvcreate -n v_backup -l 100%FREE vg_backup
# Create filesystem
mkfs.ext4 -m0 /dev/mapper/vg_backup-lv_backup
mkdir /backup
mount /dev/mapper/vg_backup-lv_backup /backup

And initialize the borg backup

/usr/local/sbin/borg init -e repokey /backup/`hostname`

After installing this /usr/local/sbin/ script

if [ ! -d /backup/`hostname` ]
echo "Mounting target /backup/"
/sbin/vgchange -a y vg_backup
mount /dev/mapper/vg_backup-lv_backup /backup
echo "done"

if [ -d /backup/`hostname` ]
/usr/local/bin/borg create -C zlib,9 -x /backup/{hostname}::{now:%Y%m%d-%H%M} / /boot
/usr/local/bin/borg prune --keep-hourly 6 --keep-daily 7 --keep-weekly 4 --keep-monthly 6 /backup/{hostname}
echo "Backup of `hostname` (/, /boot) failed as target was not mounted"
exit 1

and this /usr/local/sbin/


if [ ! -d /backup/`hostname` ]
/sbin/vgchange -a y vg_backup
mount /dev/mapper/vg_backup-lv_backup /backup

if [ -d /backup/`hostname` ]
echo "/backup/`hostname`"
/usr/local/bin/borg list /backup/{hostname}
/usr/local/bin/borg info /backup/{hostname}::`/usr/local/bin/borg list /backup/{hostname}|tail -n1|cut -d" " -f1`
du -sch /backup/`hostname`
echo "/backup/`hostname` not mounted"
exit 1

We need to check this once a week with this script:

if [ ! -d /backup/`hostname` ]
echo "Mounting target /backup/"
/sbin/vgchange -a y vg_backup
mount /dev/mapper/vg_backup-lv_backup /backup
echo "done"

if [ -d /backup/`hostname` ]
/usr/local/bin/borg check /backup/{hostname}
echo "Check of Backup of `hostname` failed as target was not mounted"
exit 1

I can add it to the cron system. Voila backup done.

chmod 700 /usr/local/sbin/????
echo "0 * * * * root /usr/local/sbin/" >/etc/cron.d/makeLocalBackup
echo '30 0 * * 0 root /usr/local/sbin/' >/etc/cron.d/checkLocalBackup
Hooking it up to OpenVPN

I added the openvpn package and installed my certs.

Mail support

I also install exim4 and mutt to do basic emailing with forwarding all root mail to my personal account.

aptitude install exim4 mutt
dpkg-reconfigure exim4-config
Adding SNMPd

Next step is to install the SNMPd and setting it up:

aptitude install snmpd
 cat <<EOM >/etc/snmp/snmpd.conf
> rocommunity PleaseSetYourOwn
> sysLocation UniMatrixOne
> sysContact
> disk /       5%
> disk /backup 5%
> disk /boot   5%
systemctl restart snmpd
systemctl enable snmpd

And now we have the minimal system running:

        │          ├─{in:imuxsock}
        │          └─{rs:main Q:Reg}
        │                    └─tail

df -h
Filesystem                       Size  Used Avail Use% Mounted on
/dev/root                         30G  1.3G   27G   5% /
devtmpfs                         483M     0  483M   0% /dev
tmpfs                            487M     0  487M   0% /dev/shm
tmpfs                            487M  6.5M  481M   2% /run
tmpfs                            5.0M  4.0K  5.0M   1% /run/lock
tmpfs                            487M     0  487M   0% /sys/fs/cgroup
/dev/mmcblk0p1                    63M   21M   43M  33% /boot
/dev/mapper/vg_backup-lv_backup  2.7T   45G  2.7T   2% /backup

free -h
             total       used       free     shared    buffers     cached
Mem:          973M       407M       565M       6.4M        55M       269M
-/+ buffers/cache:        82M       890M
Swap:          99M         0B        99M

That’s it!

We use this install for the various projects, which are coming soon.