Category Archives: linux

Failure During Switch-Version: ERROR: Acquiring lock failed

Do you really want to switch between versions ?

Enter (yes/no)? yes
Switching Version and Restarting the Appliance …

Switch version duration can vary depending on the database size
and platform configuration. Please continue to monitor the
switchover process from here.
Waiting ……………………………………

Operation failed

ERROR: Acquiring lock failed

Easily solved with a simple reboot, then retry on the switch-version.

If this does fail, next steps would be:

  • Switch-version using Recovery CD
  • TAC case with Remote Account, and TAC to edit GRUB configuration file

 

#dontcalltac

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Adding Self-Signed Certificates to Ubuntu Trust Store

I’ve been testing AXL calls using Python, and encountered the following error:

 

Traceback (most recent call last):
 File "./axl_test.py", line 14, in <module>
 result = client.service.listPhone({'name':'SEP%'},{'name':'','model':''})
 File "/usr/lib/python2.7/dist-packages/suds/client.py", line 566, in __call__
 return client.invoke(args, kwargs)
 File "/usr/lib/python2.7/dist-packages/suds/client.py", line 705, in invoke
 result = self.send(soapenv)
 File "/usr/lib/python2.7/dist-packages/suds/client.py", line 747, in send
 reply = self.options.transport.send(request)
 File "/usr/lib/python2.7/dist-packages/suds/transport/https.py", line 66, in send
 return HttpTransport.send(self, request)
 File "/usr/lib/python2.7/dist-packages/suds/transport/http.py", line 80, in send
 fp = self.u2open(u2request)
 File "/usr/lib/python2.7/dist-packages/suds/transport/http.py", line 127, in u2open
 return url.open(u2request, timeout=tm)
 File "/usr/lib/python2.7/urllib2.py", line 429, in open
 response = self._open(req, data)
 File "/usr/lib/python2.7/urllib2.py", line 447, in _open
 '_open', req)
 File "/usr/lib/python2.7/urllib2.py", line 407, in _call_chain
 result = func(*args)
 File "/usr/lib/python2.7/urllib2.py", line 1241, in https_open
 context=self._context)
 File "/usr/lib/python2.7/urllib2.py", line 1198, in do_open
 raise URLError(err)
urllib2.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)>

 

This is an easy one, as I’m connecting from my Ubuntu machine to CUCM that’s has a self-signed certificate.  I need to add this to my Ubuntu trust store.

 

Steps to resolve are:

 

  1. Install mycertifcate.pem to local machine

  2. cp to /usr/local/share/ca-certificates

  3. Rename certificate to mycertificate.crt

  4. sudo update-ca-certificates

 

jonathan@mymachine:/usr/local/share/ca-certificates$ sudo update-ca-certificates
Updating certificates in /etc/ssl/certs…
1 added, 0 removed; done.
Running hooks in /etc/ca-certificates/update.d…

Adding debian:mycertifcate.pem
done.
done.

 

The certificate will now be concatenated to /etc/ssl/certs/ca-certificates.crt and will be trusted as required.

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WebEx in Ubuntu 14.04+ for x64 systems

As per Cisco’s WebEx System Requirements specification, WebEx is only supported in x86 for Linux, and for Ubuntu specifically in 12.x and 14.x with Gnome.

However, most modern machines use the x64 architecture, so this does create a problem.  I had some fun sorting out this one ( I need it for work, so it’s pretty important I guess 🙂 ).  The steps to resolve are fairly well documented, and in summary are as follows:

 

  1. WebEx requires Java.  The WebEx system requirements guide says Java 6, but it works just fine (eventually!) in Java 8.
  2. Regarding browsers, Chrome just doesn’t work – walk away.  Need Firefox here!
  3. Java may require certain security exceptions in certain cases to get this working
  4. Even after initiating a Webex, in-meeting features such as audio, desktop share etc. are not going to work.  At the time of meeting initiation, WebEx will prompt the user to accept the download of a number of shared libraries (.so files)  to the user’s /home directory, that are stored under /home/myuser/.webex/.  These will contain package dependencies that will prevent most features from working, and should be addressed using this process.

 

There is however still a caveat listed here that needs to be taken into consideration.  It’s important to install the correct icedtea plugin to remove any conflicts:

 

sudo apt-get -y remove icedtea-7-plugin:i386 icedtea-netx:i386
sudo apt-get install openjdk-7-jre:i386 libxmu6:i386 icedtea-7-plugin firefox
sudo update-alternatives --auto mozilla-javaplugin.so

 

It definitely doesn’t look too pretty in Ubuntu, but hey, for my purposes (support) I’m happy it’s working!

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Migrating to Ubuntu – Practical Guide for Voice/Network Engineers

I’ve recently migrated from Windows to Ubuntu.  I was issued a new Dell laptop at the office after suffering through an HP device for… too long!

I decided to take the opportunity to migrate to Ubuntu.  It’s been a long time coming.  I wasn’t new to the OS, but I’m not a guru either. 🙂

 

INSTALLATION AND SETUP

The key to success here is a good plan before even creating your LiveCD/USB and installing the OS!

CONVERTING FROM WINDOWS

Some planning is involved to make this a success.  These guides helped me:

 

DISK PARTITIONING

Ensure that you have a good plan on your disk partitioning, especially for /, /home, /boot, swap:

DUAL BOOT WITH WINDOWS

Very good guide – boot loader consideration, partitioning are key here:

OS INSTALLATION

The installation itself is straightforward.

 

GRUB2 BOOTLOADER

Becomes quite important, especially for non-trivial and dual boot.

 

BASIC UBUNTU DESKTOP SETUP

CLI COMMANDS

Just the basics for day 0 if you need it:

TEXT EDITOR – VI

I’m quite a fan.  For GUI-based editors, I like Geany as well (quite a lot like Notepad++ in Windows – its pretty much an IDE).

Noteinstall vim immediately! vi has issues with certain keys in 14.04.

FILE RENAMING – REMOVING WHITESPACE FROM MIGRATED WIN DOCS

Sounds silly, but this is a really key issue to resolve.

Migrate files, then update them.  Thankfully, this is what BASH was made for, and a one-liner find does this perfectly!

 

FILE SHARING AND SAMBA

Key topic in mixed office environments.

 

PRINTING

Setting up network printers for an office environment.

 

MAIL

I chose to use Thunderbird as my mail client.  Exchange generally is a problem, but there are some solutions… Took me a while to get this working, but wasn’t too emotional.

MIGRATING PST MAIL ARCHIVES

This process is key.  The realpst package is awesome!

INTEGRATING TO EXCHANGE FROM THUNDERBIRD

Use Exquilla if you can.

This is not a free tool!

 

INTEGRATING TO OWA FROM THUNDERBIRD

I ended up using this as our exchange team couldn’t get me the EWS integration information I needed for Exquilla and auto-discovery didn’t auth with my account.

This is an excellent solution.  Watch out for package dependencies needed (JDK will be required) and untrusted sources.

CALENDAR INTEGRATION

I used DavMail for this again with DavCal.

I also integrated Gmail with DavCal.

 

THUNDERBIRD CUSTOMIZATION

Thunderbird may require some tweaking to have your client act more like Outlook – I needed this to comply to office mail standards with signatures and reply/forwarding behaviour.

Consider installing the SmartTemplate4 add-on:

Creating customized HTML mail signatures:

 

PRINTING

Easy to set up.  A good read as well

 

VIRTUALIZATION

I decided to go for VirtualBox.  Just some pointers that for things that I needed to get working with a Ubuntu Host/Win7 Guest setup.

I had some performance issues (v. high host CPU) related to:

SHARING USB

Works with vmware-tools if you using vmware, but some considerations if you use VB:

SHARING FOLDERS

Not too difficult to get working:

However, you do need to have Guest Tools loaded:

LEAVE IN WINDOWS

Some things are not better and for non-trivial tasks I didn’t even look at open source alternatives:

  • Visio
  • Office

 

PROGRAMS / SOFTWARE IN LINUX

Just the basics – it’s a great blog! 🙂

NETWORK ENGINEERING TOOLS

Just a selection of Voice/Network Engineering tools that I found useful to immediately use in Ubuntu.  This is what Linux is made for, and why I migrated I guess 🙂

VOIP/SIP TOOLS

Just to get started, the usual suspects:

  • RTMT
  • TranslatorX
  • audacity – IVR-related stuff
  • Winimage for Answer Files? – wrote a simple BASH script for that!
  • SIP Workbench in Windows – will look for a decent alternative and update…

NETWORKING TOOLS

Just some to get started with:

  • geany  – I start with this because every good engineer needs a good text editor.  For GUI-based this is my favourite
  • nmap – n00bs like me can ease into the CLI by starting with zenmap
  • gns3 – much better in linux!
  • wireshark + tshark
  • pac – excellent PERL-based replacement for SecureCRT!

A lot of scripting in Python and BASH will replace awkward Windows programs…

VPNs

As a consulting engineer, I have a number of client VPNs to connect to – covering PPTP, Cisco VPN and AnyConnect/JunOs/FortiClient.

Here’s a general Ubuntu overview:

PPTP

This is a stock standard for smaller clients.  There are occasional errors, but most are easily solved by tailing /var/log/syslog.

VPNC

I’d had tremendous issues with this, usually related to poor encryption on the server-side configuration that Linux doesn’t accept.

I wrote this wrapper script that deals with the challenges relating to 1DES weak encryption-related issues if you want to use the terminal to initiate the connection:

#!/bin/sh
sudo vpnc –local-port 0 –enable-1des /etc/vpnc/myvpncconffile.conf

I named it vpnc-connect-wrapper, made it executable and placed in it /home/myuser/bin.  It’s now available to initiate weaker connections.  I saw some solutions re-naming the default binary, which I didn’t like.

Hard-coded with the .conf filename for now…  Will add shell options later.  It’s fairly trivial to do.

The Network Manager Gnome GUI also has added a weak encryption Advanced Setting option to deal with this as well

UPDATE:

I still can’t get this working for multiple VPN connections.  I’ve resorted to doing this in my Windows VM.  I see many online posts with the same logs, and no solution in 14.04 or 14.10.  Not sure about later versions, but its been broken since before 12.04.

SSL VPN:

Got this working as well!

CHECKPOINT SNX

Used to be available as a Linux command line tool, but sadly is now only available through a browser connection – a number of dependencies to get this working, including installing Java.

 

 

OS ADMINISTRATION

LINUX KERNEL

Quite advanced.  Keep for reference for later:

 

PACKAGE MANAGEMENT

Just an overview for Linux newbies…

LINUX SYSTEM DEBUGGING

This really is an excellent tutorial on this topic

 

HARDWARE TROUBLESHOOTING

A basic overview of common troubleshooting tools and tips:

 

BASIC SYS-ADMIN HACKS

Some sys-admins tasks to get you going.  Some were useful early on.

BACKUPS + SYSTEM IMAGING

Key topics when you are new to an OS and you wanna back out a f&^k up.

 

USEFUL LINUX FORUMS

I got a lot of value out of these:

Hope this helps a few folks!

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