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Docker to solve SuperMicro IPMI iKVM – JavaWS Problems

Docker to solve SuperMicro IPMI iKVM – JavaWS Problems

icedtea-web 1.6.2 does not seem to work with SuperMicro’s IPMI Java iKVM viewer. SuperMicro’s helpful response is to only use Oracle’s Java.

net.sourceforge.jnlp.LaunchException: Fatal: Initialization Error: Could not initialize application. The application has not been initialized, for more information execute javaws from the command line.

Even when you have the right version of Java you often have to dance through security hoops or Java versions just to get it to work.

If you have Docker installed there is a great solution that avoids installing Oracle’s Java and/or tweaking any security settings. solarkennedy has created a very nice Docker container that encapsulates everything needed to access various Java based IPMI consoles.

 docker run -p 8080:8080 solarkennedy/ipmi-kvm-docker

Now point your browser to http://localhost:8080 and voila:

You are looking at a Java enabled Firefox (and OS) through a web VNC client accessed from the Docker host. Not bad!

Enable Built-in Wifi on Pogoplug v3/Oxnas Running Debian Squeeze

Enable Built-in Wifi on Pogoplug v3/Oxnas Running Debian Squeeze

I’ve not had much luck with the Pogoplug lottery. With archlinux EOL on the oxnas Pogoplugs, I’ve been Debian Squeeze with the latest archlinuxarm kernel: 2.6.31.6_SMP_820

Turns out my Pogoplug Biz had a built in wifi, but getting it to work wasn’t straightforward.

These are the steps I remember off the top of my head.

It’s worth installing:

[email protected]:$ sudo apt-get install pciutils iw wireless-tools

Make sure you do indeed have a PCIe wireless card:

[email protected]:$ lspci
00:00.0 Network controller: RaLink RT3090 Wireless 802.11n 1T/1R PCIe

In my case the card wasn’t loaded correctly (it didn’t show in the output of ifconfig).

Although the device didn’t show in ifconfig, it did show in iwconfig as ra1.

ifconfig ra1 up gave me a controls permission error.

I followed these instructions:

mount -t ubifs -o ro ubi0:rootfs /tmp/ce
sudo mount -t ubifs -o ro ubi0:rootfs /tmp/ce
sudo mkdir /etc/Wireless
/bin/cp -rfv /tmp/ce/etc/Wireless/RT2860STA /etc/Wireless
sudo /bin/cp -rfv /tmp/ce/etc/Wireless/RT2860STA /etc/Wireless
sudo nano /etc/udev/rules.d/70-persistent-net.rules

Nothing was working so I restarted out of frustration.

[email protected]:$ lsmod
cfg80211 85932 1 rt3390sta

Looks good. Issued:
modprobe cfg80211

Now for the first time I think I could bring the interface up without errors:
sudo ifconfig ra1 up

And I could scan for networks:

iwlist ra1 scanning

Now the most painful part, actually getting it to connect to your wireless network!

ifconfig ra1 up
sleep 3
iwpriv ra1 set WpaSupport=0
iwpriv ra1 set WirelessMode=Managed
iwpriv ra1 set WirelessMode=7
iwpriv ra1 set AuthMode=WPA2PSK
iwpriv ra1 set EncrypType=AES
iwpriv ra1 set SSID="MySSID"
iwpriv ra1 set WPAPSK="MyPassword"

sleep 1
dhcpcd ra1

Here the most important line was the WpaSupport=0. Before that the interface would come up but not connect to the access point. Note, the SSID and Password are in quotes – I saw many places saying they should be unquoted but this worked for me.

Finally, the WirelessMode=7 refers to a mixed n/g network. I’m not sure this line is even needed.

Poor CIFS/SMB performance on KVM Guest

Poor CIFS/SMB performance on KVM Guest

This is kind of stating the obvious. Running OpenMediaVault 0.5.48 as a KVM guest.

CIFS transfers from Windows 8.1 to OMV over gigabit ethernet maxed out at ~30MB/s.

Despite selecting Generic Kernel > 2.6 from within Virt-Manager, KVM defaulted to the virtual Realtek 8139 NIC.

Switching to the virtio driver mostly resolved the performance issues with CIFS transfers fluctuating from 60MB/s to 110MB/s.

Not sure what the source of the throughput fluctuation is, as it will be stable at 110MB/s for 10 minutes and suddenly drop.

I recommend using iftop on the KVM host to measure performance.

Your First Chome Extension

Your First Chome Extension

I made my first browser extension recently. Turns out that it is refreshingly easy.

I use Google Chrome. One of my favorite websites is SlickDeals.net, which I must admit to occasionally browsing at work. The problem is that SlickDeals makes its money via referrals. i.e. if I post a link to newegg.com, SlickDeals parses the URL and generates a redirect via a referral URL.

So:

http://www.newegg.com/Product/Product.aspx?Item=N82E16889005129

becomes:

http://slickdeals.net/?sdtid=2702819&sdfpid=47595&sdop=1&sdfid=9&u2=http://www.newegg.com/Product/....

This would be fine, however my work blocks all the intermediate sites the modified link redirects via, so it is necessary to copy the http://www.newegg.com/…. URL, which fortunately is in plaintext, from the modified URL and paste it into a new window.

After doing this 100 times or so I was pretty fed up so I wrote an extension to parse the modified URLs and return them to their original form.

Creating a Chrome extension to parse and modify page content