Technology Archive

FAQ – KVM

Posted June 5, 2012 By Landis V

http://www.linux-kvm.org/page/FAQ

Kernel Virtual Machine FAQ – self explanatory.  Page has some good links to info on KVM, may help with troubleshooting blank screen when attempting to initiate a guest from libvirt in KVM-QEMU.

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Sensu, a monitoring framework – PorterTech

Posted June 5, 2012 By Landis V

http://portertech.ca/2011/11/01/sensu-a-monitoring-framework/

Think I’ve had this page open for a while now, and I can’t remember whether I had linked to it previously or not… so I guess I’ll go ahead and do it so I don’t lose it.  Interesting solution for truly large scale monitoring.  I need to spend some time with some of the MQ apps, I can see a lot of things they would be  useful for…

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Belkin ShareMax N300 Follow-ups

Posted June 3, 2012 By Landis V

As I mentioned in an earlier post, I bought one of these little 4-port wireless routers with a gigabit switch to use primarily as a NAS server.  I’ve been so happy with it that, when I recently discovered the need for a light duty broadband router and firewall on a loaner basis, I decided to pick up another one.  With the original, I took the firmware to a Tomato version and I have found it very pleasant to work with, so I plan to do the same.  I recall having a few problems getting it where I wanted it to be, so I’ve decided to make some notes on my steps through the process this time around.  I think I may have actually attempted a direct flash to the Tomato firmware the first time, and had to perform a recovery, so I’m going to “follow the directions” this time around 🙂  Much of the instruction comes from the FatWallet forum thread at http://www.fatwallet.com/forums/expired-deals/1180400/?start=0, and specifically this post and (primarily)  this post on page 3 of the discussion.  There’s also a good link discussing recovery in between those two posts should you happen to brick a box.  I just wanted to clean these up and put them in a slightly more organized fashion than sometimes happens in a forum thread, as well as document the steps that worked for me.

Please note that I disclaim any and all liability for any damage or loss, direct or indirect, as a result of these instructions.  These notes are primarily for my own benefit and may or may not work in your individual circumstances.  You acknowledge that installing third party firmware is an unsupported action and accept full responsibility for any problems or costs resulting therefrom.

  1. I transferred copies of the following files, which I had previously downloaded, to the laptop I planned to use for the process:
    • dd-wrt.v24-18946_NEWD-2_K2.6_mini_f7d3301.bin (other versions may work, your mileage may vary)
    • dd-wrt.v24-18946_NEWD-2_K2.6_mega.bin (as above, other versions may work, ymmv)
    • tomato-K26USB-1.28.7497.IMIPSR2-Toastman-RT-Ext.trx
  2. Connected the Belkin to the laptop via ethernet, booted it up, and disabled wireless, since I don’t need it in this instance and it is interfering with the wireless connection I’m using to read up as I go.  Hard set the IP on my laptop to 192.168.2.10 with a mask of 255.255.255.0.
  3. Logged into the Belkin at 192.168.2.1.  I disabled wireless because it won’t be needed in my scenario, and because it was interfering with the laptop I was using for reference on a wireless connection to my operational network.  Saved config and restarted the router.  These steps shouldn’t be necessary in most cases.
  4. Logged back into router, browsed filesystem for, and uploaded DD-WRT mini firmware referenced above, via Utilities section, Firmware Update (had to “submit” blank password, as I had not set one). (picture)
  5. As noted in the forum instructions, I waited about 10 minutes.  Then set static IP on laptop of 192.168.1.10 (same mask as above) and attempted to open browser to DD-WRT admin page at 192.168.1.1, successfully.  The router immediately presented a page indicating an unsafe username and password, which it would not allow me to proceed without changing.  Set username and password to a known but simple value.
  6. Proceeded to Administration tab (prompted for, and entered, username and password specified above), then the Firmware Upgrade subtab.  Set the “After flashing, reset to” box to “Reset to Default settings”, browsed for the dd-wrt mega file noted above, and proceeded with the upgrade.  The router completed the upload in approximately the 300 seconds it indicated, then provided a screen with a progress bar indicating the router was restarting.  I noted that a ping I had running to the router dropped shortly after that screen appeared.  Ping remained down even though the status screen indicated that it should be back online.  Router still appeared in ARP cache, and upon clearing ARP cache on the PC and restarting ping, the entry returned but I remained unable to connect to the device.
  7. Pulled power from the router at the wall outlet.  Waited at least 30 seconds, then reconnected.  Ping resumed a few seconds later, and I was then able to open the web interface.  Was again prompted that username/password was unsafe and again entered a simple combination in order to proceed.  Observed that the router did indicate it is on the “mega” firmware in the top right corner of the page.
  8. After entering password, returned to Administration tab, Firmware Upgrade subtab, set same option to “Reset to Default settings”, located and uploaded the Tomato firmware file.  Router again indicated that it was uploading the file for approximately 300 seconds, then produced “upgrade successful” screen indicating it was restarting.  As before, ping dropped, but this time only briefly.  Was prompted for username/password, entered the combo I had set above, and was provided with a screen to continue to the web administration page (prompt indicated the webserver was “DD-WRT”, which indicated the upgrade was not completely successful).  Upon clicking continue, received username password requests again and was unable to proceed with the previously entered username and password.
  9. Hard pulled power at the wall again for a minimum of 30 seconds.  Restored power, continued to see indication that the network cable was unplugged.  Tried power pull one more time with same results – light on on front of router, but computer indicating that there was no cable connected and no ping replies or arp entries.
  10. Proceeded with 30/30/30 reset (see below).  Did observe that I was getting replies from 192.168.1.1 with a TTL of 100 after approximately the first 30 seconds, and the same after restoring power and continuing to hold reset for 30 seconds.
  11. Attempted to open a browser to 192.168.1.1, and received the CFE miniWeb Server with a location to provide a firmware file.  Browsed to the firmware file, then uploaded.  Noted that ping response times increased from ~1ms to between 6 and 10ms, then back to 1 or 2 ms after a couple of minutes.  Noted that the web interface advised that the firmware file provided was not a valid firmware image.
  12. Selected “Continue” in the advisory page, issued the command from the miniWeb server to restore default NVRAM values.  Restarted router from the CFE miniWeb page.
  13. Amazingly enough, after restarting and attempting to access default page at 192.168.1.1 again, was provided with a password prompt, entered the password I had set previously, and was provided with the Tomato router interface.  How about that.
  14. Updated username and password to something more secure, and proceeded with my configuration.

Notes

Instructions are for the Belkin Share Max N300 (F7D3301/F7D7301) v1.

The two DD-WRT files are out of order when you browse for the files (mega is alphabetically before mini… keep it in mind)!

30/30/30 reset method:  Hold down reset button for 30 seconds.  While continuing to hold reset, power off by unplugging from wall outlet and leave unpowered for 30 seconds with reset held.  Without releasing reset button, restore power to modem; wait 30 seconds, then attempt connection to web interface again.

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http://bderzhavets.wordpress.com/2011/04/27/setup-kvmqemuspice-on-ubuntu-11-04-via-ppaserge-hallynspice2/

Just recently read about the spice protocol for remote display/audio/etc, and it looks very promising.  Finally got my new build system up and running on Ubuntu (turns out that “nomodeset” as a kernel option was key to that, and had to work around through a few hoops… still not sure whether it’s running UEFI or typical, but it’s running, so I’m done caring).  Next step is to get a couple of virtual machines running, and see if I can justify shutting down a couple of other systems and end up saving power, as I suspect my new build is quite a bit hungrier for juice than the miscellaneous small boxes I currently run.  Will have to hang the Kill-A-Watt off it at some point and test to be sure.

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http://www.virtualizationpractice.com/and-then-there-were-three-nxtop-enterprise-morphs-to-xenclient-enterprise-16018/

I’ve been watching this space for a while, and I continue to find it frustrating.  Virtual Computer’s NxTop was one of the more promising platforms to develop into what I’d really like to see this area of computing become:  a type 1 virtualized environment capable of running multiple operating systems simultaneously (much like the existing server virtualization environment) with the ability to display consoles for the running guests (which is lacking in the existing server environment), and perhaps eventually provide direct guest access to certain devices such as video cards to achieve maximum performance from that component.  XenClient/XCI was the other promising platform in this area, so hopefully Citrix does see this as an opportunity to develop and build out a product (hopefully without leaving open source behind… I see a lot of advantages in being able to run something like this at home too) rather than just an opportunity to swallow some competition and further entrench the VDI model, which I find immensely unpalatable.

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softflowd – fast software NetFlow probe

Posted May 14, 2012 By Landis V

http://www.mindrot.org/projects/softflowd/

Keep in mind for Linux-based infrastructure.

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http://raffy.ch/blog/2012/03/24/advanced-network-graph-visualization-with-afterglow/

Slick use of AfterGlow for log analysis.

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