Increase Ubuntu VM Disk Space

I ran into a very familiar problem (for me anyway) on an Ubuntu 18 virtual machine today. It started with, what I thought was, a Cisco ISE issue. Cisco ISE reports that I wanted to write to a repository ended up as empty files (0 bytes). Initial thought was that I ran into an Cisco ISE bug related to repositories, but it turned out that my Ubuntu server had run out of disk space;

Err:2 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
  Error writing to output file - write (28: No space left on device) [IP: 91.189.88.24 80]

A quick df -h revealed that my Ubuntu server had only 4GB (out of the 100GB I assigned in VMWare).

willem@ubuntu:~$ df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               967M     0  967M   0% /dev
tmpfs                              200M  1.1M  199M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  3.9G  3.9G    0M 100% /
tmpfs                              997M     0  997M   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              997M     0  997M   0% /sys/fs/cgroup
/dev/loop0                          90M   90M     0 100% /snap/core/7713
/dev/loop1                          90M   90M     0 100% /snap/core/7917
/dev/sda2                          976M  222M  688M  25% /boot
tmpfs                              200M     0  200M   0% /run/user/1000

So, now I had to add the unassigned 96GB to the Ubuntu filesystem. Thankfully, askubuntu to the rescue.

root@ubuntu:~# lvm
lvm> lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv
  Size of logical volume ubuntu-vg/ubuntu-lv changed from 4.00 GiB (1024 extents) to <99.00 GiB (25343 extents).
  Logical volume ubuntu-vg/ubuntu-lv successfully resized.
lvm> exit
  Exiting.
root@ubuntu:~# resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv
resize2fs 1.44.1 (24-Mar-2018)
Filesystem at /dev/mapper/ubuntu--vg-ubuntu--lv is mounted on /; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 13
The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 25951232 (4k) blocks long.

root@ubuntu:~# df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               967M     0  967M   0% /dev
tmpfs                              200M  1.1M  199M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   98G  3.4G   91G   4% /
tmpfs                              997M     0  997M   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              997M     0  997M   0% /sys/fs/cgroup
/dev/loop0                          90M   90M     0 100% /snap/core/7713
/dev/loop1                          90M   90M     0 100% /snap/core/7917
/dev/sda2                          976M  222M  688M  25% /boot
tmpfs                              200M     0  200M   0% /run/user/1000
root@ubuntu:~# 

Capture Network Traffic With Wireshark Under Ubuntu

When you install Wireshark on Ubuntu Linux you need to be root to be able to capture traffic. The standard user doesn't have enough privileges to do this. 

A workaround for this is to add the user to a wireshark group and give the group special permissions. Afterwards, you're able to cpature traffic in Ubuntu with Wireshark, without needing root access. 

The complete list of commands: 

sudo groupadd wireshark

sudo usermod -a -G wireshark <YOUR-USER-NAME>

sudo chgrp wireshark /usr/bin/dumpcap

sudo chmod 750 /usr/bin/dumpcap

sudo setcap cap_net_raw,cap_net_admin=eip /usr/bin/dumpcap

sudo getcap /usr/bin/dumpcap

Just reboot, or log out and back in, and you're finished. 

HAPPY CAPTURING

Wireshark on Ubuntu 10.10

Last week, I acquired a small netbook @ work for testing purposes (HP Mini 5103). You don't want to know how handy a second laptop is when you're testing authentication environments.

For flexibility purposes I installed a dual-boot with Microsoft Windows 7 Enterprise and Ubuntu Linux v10.10 from a USB Flashdrive (1, 2), erasing all the preinstalled HP/McAfee crap. This all worked like a charm, up to the installtion of Wireshark in Ubuntu. Starting the sniffer application resulted in an empty list of network adapters. No network adapters mean no capturing capabilities.

This was probably related to the lack of rights while starting the application. Running it from the terminal with sudo resulted in some weird error regarding a display-thingy (which is still the main reason why Linux isn't penetrating the desktop market).

While searching the Interwebs, I found the following solution. Which, after some alterations to the commands, the following worked for me;

In a terminal session, execute these commands:

sudo addgroup –quiet –system wireshark (this command simply didn't work in my case)
sudo chown root:wireshark /usr/bin/dumpcap
sudo setcap cap_net_raw,cap_net_admin=eip /usr/bin/dumpcap

usermod -a -G wireshark <my user name>

Reconfigure the Wireshark Common package and answer ‘Yes’ to the question ‘Should non-superusers be able to capture packets?

sudo dpkg-reconfigure wireshark-common (I needed to add the sudo part on this command)

After rebooting the laptop, Wireshark started normally with all the network interfaces available for capturing traffic.

UPDATE: I did a reinstall of the OS, and this time Wireshark started 'properly' from the Terminal application by typing (without the quotes) 'sudo wireshark'.

Why Linux Won't Work

.... for me at this moment (and probably for most others).

I'm still in the fase of migrating my Windows server to a more 'reliable' Operating System. The new server should cover the following basic functionalities:

• Filesharing (either via Samba or NFS)
• Webserver with PHP and Coldfusion
• SSH server
• RADIUS Server
• Central user database (e.g. an LDAP server)
• a NZB downloader of some sort
• etc.

Up till now I've tried several Linux distros (Ubuntu 7, Ubuntu 8, and CentOS 5), and none of them are that easy to configure.

It seems that NFS isn't that easy to configure, since Apple OSX requires some special features (standards anyone??). Especially when you want some sort of user authentication. Just do a search on Linux, NFS and Apple OSX.

So after NFS didn't really work, I tried SMB for filesharing. While CentOS has some GUI to configure the shares, it lacks the interface of permissions for users...
You create users within the Linux environment, and if you wanna connect to a Samba share you need to configure additional users (in a different userdatabase).
This can be done by synchronization, but you need to do some scripting etc.

So far I've managed to install a working SSH server (with x509 authentication) and a Webserver.

When I compare this with Windows.... Well, there's no real comparison. Windows has a real central user database (not talking about the Active Directory here, but the local user database). And every service I need can talk to this database, and every service recognizes this database. No need to start 'hacking' some configuration files to make it work.

Well, as long as there's no new (read:better) interface of configuring those services and combining them with a shared user database ....

LINUX >> /dev/null

Recommendations can be left in the comments (if there are any)......

Ubuntu 'Hardy Heron' Released

As of yesterday, the latest Ubuntu release 'Hardy Heron' is available for download (both client and server). Every time a major Linux distri(bution) hits 'the shelves', the Linux community roars. With each release (Ubuntu or whatever flavor) the Linux community gets closer, and closer to Windows.

Even though the OS itself is getting better and better. It still lacks the support of decent major software like Adobe Creative Suite, etc. It's missing the software people use in every day (business)life.
Sure, there a million different ways of running Microsoft Office or Adobe Photoshop on a Linux OS, but these require a commercial piece of software (CrossOver) , or in depth knowledge of the OS to make it work (Wine in some cases). Two things that shouldn't be required. Not if you're used to Windows (or Apple's OSX). And even if you find a 'substitute' it's most likely to have an awful user experience.

The average housewife won't use Linux, because her friends all use Windows. All those nice little Windows programs, which makes life easier (or a living hell with all the mal/spyware out there). So if the Linux community wants to make a difference they need to create some sort of critical mass (by their selves, or by Microsoft screwing up) to get the attention of the 'normal' user. But in a community where there's no real (commercial) business model, it's gonna be damn hard.

Microsoft created this critical mass by playing (probably) the best marketing trick in the world; Release Windows 95, and turn a blind eye to those who use a pirated copy at home. The home users create demand on the workfloor, so businesses start to use it on their workstations. Soon everyone was addicted. And now it's damn hard to beat the addiction.

B.t.w., Apple is doing it a lot better. They created a nice and stable OS (just like the average Linux desktop distribution), BUT the OS has ALL the relevant drivers for the hardware used. ALSO they have a complete (and cheap) software suite (iLife and iWork), which is more than enough for the average family. No need to search the caverns of the Internet for software, and they look and feel the same as the OS.

So, I guess that my conclusion is that the OS is nearing perfection, but it (Linux in general) lacks good and decent third party software (and a good marketing machine :) )

In the mean time; I'm gonna upgrade my Linux (mail, web, and ssh) servers at work to 'Hardy Heron'.

VMWare and Firewall / VPN Clients

Well, that was another morning well spent....

A couple off weeks ago I started experimenting with FreeRADIUS on Ubuntu server (v6.06.2 TLS). Mainly because I needed to test some things for work. So I used VMWare to experiment. The networking part was set-up as Bridged.

Today, I wanted to test with iperf (a tool for network performance testing). So I launched the virtual machine, but there was no network connectivity. ifconfig showed that eth1 didn't received an IP adres.
So I ran every possible test there was;

• restarted the interfaces (/etc/init.d/networking restart)

This resulted in the following;

Listening on LPF/eth1/00:0c:29:68:e3:eb
Sending on LPF/eth1/00:0c:29:68:e3:eb
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12

The "DHCPDISCOVER" messages continue about 4 times, then the message:

No DHCPOFFERS received.
No working leases in persistent database - sleeping.

• restarted the DHCP server
• rebooted the virtual machine
• changes the networking to NAT instead of Bridged (this way, connectivity was restored, but not the way I wanted. I needed Bridge-mode)
• Tried to run the virtual machine on OSX (VMWare Fusion), which worked surprisingly.

After this I ran Wireshark on my server to see if DHCP request were coming in.... And you might have guessed; No DHCP request were reaching the DHCP server. So the problem was work PC related.... As a matter of fact, I had the Cisco VPN client running..... Which didn't allow the DHCP request broadcast.

Shutting the VPN client down solved the DHCP problem. After the virtual machine worked I could reinitiate the VPN.

Mental note to myself: do NOT boot/restart the virtual machines when the VPN is up.