Realtek RTL2838 DVB-T tuner failure

It would appear that my Realtek RTL2838 DVB-T tuner has failed. I can no longer get it to record any more using TvHeadEnd. I noticed I hadn’t got any recordings the past few days and I’ve just checked all the connections. At this stage I think it’s safe to conclude that it’s gone.

It certainly didn’t last very long. I might end up getting another one, however not in a big rush. I need to do some other work with the hardware, so I might move onto that project in the meantime.

I note that dmesg output is showing the following, which based on some of the word is related to the hardware failure of the device.

[ 5520.964222] kdvb-ad-0-fe-0  D ffff88011d96eb20     0  2406      2 0x00000000
[ 5520.964226]  ffff88011ce17d08 0000000000000046 ffff88011ce17cf8 ffff880127c54580
[ 5520.964230]  ffff88011ce17fd8 ffff88011ce17fd8 ffff88011ce17fd8 0000000000014580
[ 5520.964233]  ffff880121f29770 ffff88011cf05dc0 0000000000000286 ffff88011ce17d90
[ 5520.964237] Call Trace:
[ 5520.964242]  [] ? dvb_usb_data_complete_204+0x20/0x20 [dvb_usb_v2]
[ 5520.964246]  [] schedule+0x29/0x70
[ 5520.964250]  [] wait_schedule+0xe/0x20 [dvb_usb_v2]
[ 5520.964254]  [] __wait_on_bit+0x5f/0x90
[ 5520.964258]  [] ? dvb_usb_data_complete_204+0x20/0x20 [dvb_usb_v2]
[ 5520.964261]  [] out_of_line_wait_on_bit+0x7c/0x90
[ 5520.964265]  [] ? wake_atomic_t_function+0x40/0x40
[ 5520.964270]  [] dvb_usb_fe_sleep+0x114/0x1b0 [dvb_usb_v2]
[ 5520.964277]  [] dvb_frontend_thread+0x177/0x780 [dvb_core]
[ 5520.964281]  [] ? add_wait_queue+0x60/0x60
[ 5520.964288]  [] ? dvb_frontend_ioctl+0x160/0x160 [dvb_core]
[ 5520.964291]  [] kthread+0xc0/0xd0
[ 5520.964295]  [] ? flush_kthread_worker+0xb0/0xb0
[ 5520.964299]  [] ret_from_fork+0x7c/0xb0
[ 5520.964303]  [] ? flush_kthread_worker+0xb0/0xb0

Ubuntu 12.04.4, TvHeadend and Realtek RTL2832U USB tuner

This week I setup an old Dell Optiplex 755 tower with Ubuntu 12.04.4, TvHeadEnd and Realtek RTL2832U USB tuner to perform some DVB-T recordings. The installation I performed of TvHeadEnd is the exact same one I documented some months back when I used the same USB tuner on a Raspberry Pi. You can read about it here.

The installation was flawless and simple as you’d expect. The system has been running a few days now and capturing what I want. It also allows me to point VLC client on other machines at the system to network stream any of the DVB-T channels the tuner can tune against (also shown in the previous post linked above).

Thinking of buying another tuner to be honest, so I can record from 2 different channels that don’t share the same stream/multiplex id.

System security and sudo

Was reading twitter, as I would typically do when in transit. Came across a really good post on sudo[1] and security. Highly recommend having a read.

Check it out here.

Some excellent information contained in the post.

[1] – Sudo (su “do”) allows a system administrator to delegate authority to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while providing an audit trail of the commands and their arguments.

Linux installation on SSD

I am going to be installing a Linux desktop onto an SSD drive soon, and I have started to research. If you have done this already and found something you needed to do that was not documented, please drop me a line.

My aim is to setup my Intel i3 Mini-ITX system with a Linux Desktop install (Ubuntu probably) and eventually drop in some more storage, since the case and motherboard could handle 4 more SATA devices, not including the optical and SSD boot drive.

Figured I could end up running for additional storage, services and desktop environment for doing other tasks like maybe get VMware Workstation going so I can run my existing virtual machines.

The current duties it does that requires Windows will move onto a laptop I will purchase at the end of this month, or early next month.

Linux system hardening

I really need to sit down and do some research on Linux System Hardening, as I really want to take a look at any kernel hardening that can be done on the system. i.e. I don’t want users to be able to see who else is on the machine via the output of commands like ‘w’ and ‘who’. I remember grsecurity use to be available to do this, so I should look around to see if this is still valid or do we do it another one.

I did find the following web post about SSH hardening which I enjoyed reading here.

If you’ve done Linux System Hardening recently, chime in on the comments with your experience.

New PC laptop purchase

I was going to build up another mini-ITX desktop, however the more I look at it I am better off buying one of those Dell Outlet Inspirion laptops. As  I end up getting a PC that can be used as a desktop replacement and doesn’t need any more hardware purchased. i.e. keyboard/mouse/monitor. So I am monitoring the outlet site the past week watching what Intel i3 Third generation systems come up and the prices.

The PC laptop will probably run Windows 7 x64 Home (or Windows 8.1 if my work VPN finally ends up supporting it). While my existing mini-ITX desktop (i3/16gb ram) will probably be converted to a Ubuntu desktop, so I can implement lxc containers again and some other workload on it. Really want to get tvheadend setup on it and plug in the USB tuner I was using with my Raspberry Pi. Remember the post here, about that?

If I get some time this weekend one evening going to install a temporary hard disk into my desktop and do a Ubuntu 12.04.4 install and do some messing about to ensure the hardware all detects fine and resolution of monitors works fine. The system uses an Intel HD 4000 onboard, so I hope accelerated video works or that could be a problem.

Looking to purchase the laptop the end of this month or early next month.

Confluence 5.4.2 installation problem – Confluence not starting post install

This is not something I’ve hit before, however this is my first time installing Confluence 5.4.2 x32 on a Exigent VPS account. Post the installation, I got the message indicating that the service has started and you should connect to it to finish the configuration.

However, nothing was found to be running on the default port of 8090, so I checked the catalina.out file in the logs folder to determine what was written. It was showing the lines below;

Error occurred during initialization of VM
Could not reserve enough space for object heap
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

At this point I figured I needed to change the amount of memory being allocated to java during startup so I went looking to see where this was being set from. Turns out its in the setenv.sh file in the bin folder.

On the first line of the file, change the -Xmx512m to something a little smaller, if your running on a VPS that doesn’t have enough available memory to let it have 512Mb of ram. Save the change and fire it up via “start-confluence.sh” and it should load up fine.

EDIT: It’s safe to say that my low end VPS account cannot really run the Confluence install, as it failed to create the database in MySQL and put the box under serious load due to all memory being consumed, which subsequently pushed out the load average. See below;

top – 09:56:16 up 45 days, 16:50, 3 users, load average: 70.49, 37.55, 15.18
Tasks: 70 total, 3 running, 67 sleeping, 0 stopped, 0 zombie
Cpu(s): 12.1%us, 87.9%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 1048576k total, 1048576k used, 0k free, 0k buffers
Swap: 0k total, 0k used, 0k free, 0k cached

I gave it a go nonetheless :)

Confluence 5.4.2 x64 installation error

I was attempting an installation of Confluence 5.4.2 x64 from the binary file that can be executed and it failed like below;

root@hostname:/home/username# ./atlassian-confluence-5.4.2-x64.bin
Unpacking JRE …
Starting Installer …
./atlassian-confluence-5.4.2-x64.bin: 466: /home/username/atlassian-confluence-5.4.2-x64.bin.17671.dir/jre/bin/java: not found

I’ve seen this problem before with another product, so I knew immediately what the problem is. It’s due to executing the x64 version on a 32bit Linux.

Go download the 32bit version of the file and execute it. It will work.

Wifidog and Authpuppy

I’ve been trying to get Wifidog and Authpuppy going, however failed to get the end to end solution working.

I was able to get Wifidog installed and compiled. In addition to getting Authpuppy going, but getting them to work together is not working  for me.

I want to use a small pc with dual nics to connect to the local network (which gets out to internet) and the other nic connected to 1 or more Access Points.

The network with the Access Point doesn’t appear to have its traffic intercepted by Wifidog at all, and that’s the bit that I am stuck with currently.