In this blog post I am going to demonstrate how to easily setup a virtual server at Hetzner. This setup will work for most other vServer operators as well, but some adjustments may be required. Prerequisite is that you are able to access the console of the server while booting, as you need to be able to enter the passphrase. You also need to be able to boot into some sort of “Rescue System” for the setup. This is no in-place setup. In Hetzner’s “Robot” this is pretty easy.
One thing to consider regarding security: fully encrypting a vServer might seem… senseless, as the host operator can easily copy the whole memory of the VM while running and extract the key this way. True. There is no way around this fact. My reason for wanting a fully encrypted system is more of the way that I want to be sure that the data is encrypted on the storage system. I want to protect from being unable to ever fully wipe the persistent data from disk in case I cancel the VM, the VM gets moved to a new host, or a failed disk is sent in to the manufacturer. For me, this is a compromise I can accept. YMMV.
You can also try this HOWTO under VirtualBox with the System Rescue CD ISO images. Actually, that’s where I verified all steps are working.
So, let’s dive into the fun of the HOWTO. BEWARE! THIS TUTORIAL WILL WIPE ALL DATA ON YOUR VSERVER! I TAKE NO RESPONSIBILITY IF YOU LOSE DATA! IT MIGHT ALSO NOT WORK FOR YOU. USE THIS AT YOUR OWN RISK!
The following steps will partition the disk, setup LVM and LUKS, install Ubuntu 12.04 and prepare the system for reboot. Most parts can be copied line-by-line. Please beware that there are some parts in this tutorial that needs to be adjusted: UUIDs of partitions, hostname, username, and most important: network setup.
Continue reading “HOWTO: Fully encrypted vServer with Ubuntu 12.04”
When upgrading to Ubuntu 10.04 I noticed two annoyances (which actually are just a matter of personal taste):
- The OSX-like positioning of the close, minimize and maximize buttons on the left instead of the right of the window.
- The fade-out (invisibility) of other windows when using Alt-Tab for tabbing through the available windows on the current desktop.
As I tend to forget and need to Google every time I encounter a newly setup 10.04 system, I now jot down the settings to change.
For changing the window buttons:
- Change its value to
For changing the opacity of inactive windows during Alt+Tab window switching:
- Change it to any value you like, where 100 is fully visible and 0 is totally invisible.
Today I finally received my brand-new Ocz Vertex2 OCZSSD2-2VTXE120G 120GB and eagerly wanted to install it in my 4-year-old HP workstation which currently is running Ubuntu 10.10 exclusively.
After setting up the alignment according to some tutorials I found online, I started the setup process. Shortly after starting the copy step of the installation, the whole process came to a grinding halt with filesystem errors. Looking into the kernel debug messages it seemed like SATA commands were causing errors. After checking hardware, cables and switching SATA ports, I began researching the issue and soon found that the issue might be fixed in the next firmware version of the drive. So I wanted to upgrade from 1.23 to 1.24, which could only be done in Windows…
After installing a trial of Windows 7, I finally wanted to upgrade the firmware, but the drive was not detected, but was accessible. The release notes indicated that I would need to switch to AHCI mode. After several attempts, includig a BIOS update, I realized that there was no way to do this with my old hardware, as my nForce 430 chipset simply doesn’t support it.
So my only remaining option was to simply try the kernel arguments I read to be the fix for 1.24 with the 1.23 hardware.
So, if you add the following kernel option during installation and afterwards for every boot, the disk seems to work quite well (source):
Actually, this forces the ATA driver in Linux to not issue any reset commands on the bus. I really don’t understand why this improves/fixes the problem, but it seems the device has issues when being reset on my chipset. I can also notice this that in 2 out of 3 attempts if I reboot the PC the disk is not recognized any more before I reboot again.
Despite these issues, the SSD now runs with astonishing performance with the suggested 32 head / 32 sector alignment, and a 512kB partition alignment scheme. After an initial TRIM with hdparm‘s
wiper.sh I enabled
-o discard for my ext4 partition and could also verify using hdparm that this results in the sectors being trimmed. Please note, that you need to manually compile and install the latest hdparm version on Ubuntu 10.10, as the included version fails with the very long free block list and doesn’t handle splitting the sectors in multiple requests. The latest version doesn’t have this issue any more.
udev renames you network interfaces
Sometimes udev renames your devices. This happened to me when upgrading a server, eth0 suddenly became eth1 and vice-versa. Of course, this broke nearly all firewall scripts on the server… There is a nice explanation how to get udev to name your devices the way you want.
Visual Studio 2005 Service Pack 1 on Microsoft Windows Server 2003
When installing Visual Studio Service Pack 1 under Windows Server 2003, it might fail because it cannot verify the signature. You should take time and visit the link provided in the error message, because it will take you to a hotfix that will correct the problem.
(via Mark Caroll’s Blog)
VMWare Server on Ubuntu 8.04
A nice tutorial for getting free VMWare Server 1.0.5 running on Ubuntu 8.04.
As I definitely should post more on my blog, I now try to start a new series: “Nice to know”. It will be a collection of interesting things I consider memorable but which don’t deserve their own blog-post.
Tricke allows you to limit bandwith for processes that do not support bandwith limitation out-of-the-box. It works by preloading and simulating the socket API. You use it as a wrapper when starting the process, like trickle -d 80 someapp.
You can use it to limit rsync speed for instance (thanks to http://www.yak.net/fqa/404.html): rsync -auvPe “trickle -d 80 ssh” user@host:/src/ /dst/
VMWare Tools and Kernel 2.6.24
VMWare Tools out of the box do not install on kernel 2.6.24 (as used in Ubuntu 8.04 for instance). A possible solution is described here. It is based on using the open-source version of the VMWare tools (open-vm-tools).
After quite some time, a new version of my favorite encryption tool is out: TrueCrypt developers have released version 5 of their product, introducing a new killer feature (among others): System Volume Encryption with pre-boot authentification (only Windows 2000/XP/Vista). This means, that TrueCrypt will encrypt everything on your system drive, including page- and hibernation file,
finally making hibernation a safe and easy possibility.
I am going to look into this next week, as I need my notebook on Saturday (just in case anything goes wrong).
Update 2007-02-08: As my first commenter below points out, it seems hibernation is disabled by TrueCrypt while having your system partition encrypted. I don’t really understand why at the moment, but I will investigate further. For me this is a primary show-stopper, as this was the long-awaited functionality I was waiting for.
Nitpickers Corner¹: Of course I am aware why encryption and hibernation in general are no-goes together, but I don’t understand why this is an issue when full-system encryption is enabled.
Update 2007-02-08 (again): Ok, in this TrueCrypt forum thread they explain why they cannot support it at the moment: Windows treats the hibernation file differently, it seems to bypass the TrueCrypt driver and therefore would still write keys to disk without encryption. Ok, still get to wait for my dream feature then, but I still refuse to buy PGP 🙂 Thanks to the developers for their great work anyhow!
¹ a tribute to Raymond Chen 🙂
[tags]security, encryption, truecrypt, windows, linux, osx[/tags]
I am currently thinking a lot about the OpenMoko project. Unfortunately OpenMoko at the moment provides hardware which is limited to GPRS, Bluetooth, and/or USB 1.0 for connectivity. In autumn there should be the next generation which should include a WLAN (and maybe even UMTS?) support. It will be called Neo 1973 – GTA02.
Together with Austrian-based one “H.U.I. Starter” rate (250MB @ UMTS, reduction to 56kBit/s above, 10€/month) this would be a nice package. However, if I could have UMTS, well, that would be better. Personally, WLAN is even more important for me, I could use it in the office or in my home, where I have WLAN access available and fall back to GPRS while being “on the road”.
For me this means: standby for autumn, because I can’t afford to invest US-$300 now and another US-$450 in a couple of month. Still, I am really, really interested in OpenMoko (and normally I wouldn’t invest that amount of money into a hobby of mine). Which means, I am standing by and waiting for news from the OpenMoko community…
In the meantime, if you understand German, you could listen to this very interesting Chaosradio Express Podcast.
On YouTube there are some very interesting videos about the Neo 1973.
This is cool! If you want to have a mobile phone based on Linux and pure OpenSource software, OpenMoko might be the right thing for you! I’m not so much in mobile development, but I find this almost more appealing than the iPhone, which at the moment is a very closed platform. If I find some time for a hobby like this, this US-$ 300 would be a nice investment. I hope this becomes a success to reward the company and the idea to explictly invite hackers/developers (both software & hardware) to improve a phone. A nice contrast to the usual anti-reverse-engineering and “hacking” philosophy most companies go along with.
Edit 2007-07-18: I accidentially misspelled OpenMoko as OpenMonko in the inital release, both in the title and in the text. I corrected this and the URL of the article to reflect the real name of the project: OpenMoko.
I am using cryptsetup LUKS for storing encrypted office data on my USB memory stick (just in case I lose it). I recently installed Ubuntu 7.04 on one of my machines and wanted to open the encrypted partition using cryptsetup luksOpen, which failed with a rather strange
Unable to make device node for ‘temporary-cryptsetup-32733’
While searching around the net I found a lot of people asking the same question but hardly any answer, until I finally read this article
on the Ubuntu forum.
The solution to the whole problem is rather simple:
sudo mkdir /dev/.static/dev/mapper
With a little bit more verbose error message of cryptsetup I might have figured this out myself…
Ever happened to run out of random numbers?
Well, if you are using Apache together with mod_ssl you can easily run into the situation that after starting up Apache, requests to it will block up to several minutes or time out. This happenes, if Apache is configured to use /dev/random as a source for random numbers which are required in the initialisation of mod_ssl and similar, if you have to few entropy information left for the generation of more secure random numbers.
As suggested in a Gentoo Forums article, you can emerge the tool sys-apps/rng-tools, which provides you with rngd, a daemon collecting entropy from hardware random number generators and feeds /dev/random with this data.
If you happen (like me) to not having a hardware random number generator on your server’s mainbord, rngd will use /dev/urandom as a source of entropy and mix it with entropy collected from your system. While this will indeed result in a certain drop of “randomness” of /dev/random, it still has major advantages by reducing the startup time of apache to several seconds, as /dev/random will not block any more.
Don’t forget to add rngd to your server’s default runlevel (rc-update add rngd default).