I was going to write a post on how to install and configure your own virtual SSL-VPN server as I had in mind to make one myself as a means to surf safely while on hotspots and to access my System Center lab at home. I’m not gonna do that. Instead I just want to point to this free, already pre-configured, OpenVPN Virtual Appliance. Just follow its instructions and it will work quite nicely. Have fun.
Ok, so I got the task to install the Linux Integration Service for Hyper-V R2 on a RedHat Enterprise Server 5. Something that turned out to be a bit more to handle than I would have thought. So here’s a little How-To. Preparations Read the documentation provided in the Linux Integration Services download. Much of the information in this article is in there, but some parts are not. Otherwise I would not have bothered writing about it. 😉 I’m not going to go through the OS installation process here, but make sure to select the “Software Development” packages since you will be needing it. In case you missed it, you can install them later by running these commands. # yum groupinstall "Development Tools"# yum install kernel-headers I’m not actually sure that you need to run the kernel-headers install manually or if it’s included in the “Development Tools” package. The first gotcha i ran into was the fact that the link to the Linux Integration Services–previously known as Linux Integration Components or LinuxIC–on RedHat’s information pages gave me a 404 and a redirect to a bing-search that returned the exact same 404. The page have simply been removed by Microsoft without any form of redirection to the new page. Anyway, a search on http://download.microsoft.com for “Linux Integration Components” do return the new page, and that’s where I learned about the new name. Thank you for making it easy for us Microsoft! Here’s a direct link to the search on the current name. And here’s a direct link to the actual download page. This download contains an ISO file that you can mount using the Hyper-V- or VMM-console, or you can do as I did and download the ISO to the virtual machine, mount it locally, copy the files and unmount it. Like this. # mkdir /mnt/ISO# mount -o loop /root/LinuxIC v21.iso /mnt/ISO# mkdir /opt/linux_ic_v21_rtm# cp /mnt/ISO/* -R /opt/linux_ic_v21_rtm/# umount /mnt/ISO
Error Description Here’s a little trouble-shooting guide for discovering Linux systems from OpsMgr R2 when getting the following error from the wizard: <stdout>Generating certificate with hostname="COMPUTERNAME"[/home/serviceb/TfsCoreWrkSpcRedhat/source/code/tools/scx_ssl_config/scxsslcert.cpp:198]Failed to allocate resource of type random data: Failed to get random data - not enough entropy</stdout><stderr>error: %post(scx-1.0.4-248.i386) scriptlet failed, exit status 1</stderr><returnCode>1</returnCode><DataItem type="Microsoft.SSH.SSHCommandData" time="2009-08-05T11:15:01.5800358-04:00" sourceHealthServiceId="0EB1D6DA-202C-7FC5-3D46-BDBB9208547D"><SSHCommandData><stdout>Generating certificate with hostname="COMPUTERNAME"[/home/serviceb/TfsCoreWrkSpcRedhat/source/code/tools/scx_ssl_config/scxsslcert.cpp:198]Failed to allocate resource of type random data: Failed to get random data - not enough entropy</stdout><stderr>error: %post(scx-1.0.4-248.i386) scriptlet failed, exit status 1</stderr><returnCode>1</returnCode></SSHCommandData></DataItem> But first, a little background on the actual “problem”. To generate the certificate, the entropy needs to be high enough to generate random data for the certificate creation. Without the certificate, the OpsMgr agent won’t be able to open up communications with the MS. So, what creates this entropy we need? Bluntly put, a selection of hardware components that are likely to produce non-predictable data. Like a keyboard, mouse and a monitor or videocard. Of course, there’s a lot more to it, but we really don’t need to know this. What we need to know is that there has to be a “bit bucket” of more than 256bytes of entropy for the certificate creation process to succeed. We also need to know that more enterprise-ish servers, like rack- or blade-servers tend to be void of things like directly attached keyboards, mouses and monitors that the linux kernel needs to be able to generate entropy. And herein lies the problem. If you have a new server that is not in full service (likely since we are trying to deploy the monitoring on it) which means that there’s not much random data flowing through the hardware and there’s no keyboard or mouse or monitor connected to it there is quite the risk that the system entropy is going to be very low. Of the linux systems that I have been deploying OpsMgr agents to, about half have failed because of “Not enough entropy”. So, here’s the steps I usually takes to ensure that discovery works. I use PuTTY to connect to the soon-to-be-monitored servers. This guide also assumes that you have SU rights on the system since all of these steps (except #1) needs it. Workaround 1. Check you current entropy cat /proc/sys/kernel/random/entropy_avail Is it less than, or close to, 256? It probably is. If you don’t feel like connecting a mouse and start wiggling it around—not really feasible in a data center—and see if the entropy increases, you can generate your own random data. 2. Generate you own random data. Be advised that this forced entropy will not be as random as the system-created on and thus not as secure. How much more insecure it is, I don’t know, and quite frankly I prefer to have my systems monitored yet slightly less secure than not monitored at all. Anyway, you can force your own random data by running:
Ok, so I reinstalled my linux partition with Ubuntu 9.04 x64 and decided to try EXT4 on the root partition. Like, yesterday. Managed to get the Citrix client running (way more easy on Ubuntu than Fedora, I’ll be back on that) and all without too much fuzz. First reboot gave me a “let’s FSCK!”. So I FSCK-ed and booted up to the desktop. Second reboot gave me a “let’s FSCK!”. And I did. Booted to the desktop. Third boot went smoothly, but all of a sudden all the icons decided to go AWOL. Rebooted again. Fourth boot gave me a “let’s FSCK!”. I replied with “Well FSCK You!” Fifth boot gave me a “let’s FSCK!”. I rebooted back to Windows 7. Tonight I am reinstalling Ubuntu 9.04 x64 with EXT3.