Dank der baulichen Gegebenheiten (Stahlbeton) hatte ich bislang immer mindestens zwei WLAN-Router in Betrieb – pro Etage einen. Nur so war durchgÃ¤ngiger WLAN-Empfang zu gewÃ¤hrleisten. Dank stÃ¤ndiger Aktualisierung der Hardware war bislang noch 802.11n das MaÃŸ der Dinge. Seit einer Weile arbeitet hier aber auch ein Router, der das neue 802.11ac unterstÃ¼tzt: ein Belkin AC1200.
Und mit dessen Einzug fingen dann auch die Probleme an. Clients verloren immer wieder die Netzwerkverbindung, gelegentlich lieÃŸ sich gar keine Verbindung aufbauen und viele Ã„rgernisse mehr. Die LÃ¶sung war aber so einfach, dass ich zunÃ¤chst gar nicht drauf gekommen bin: Einfach den zweiten WLAN-Router abschalten. Der AC1200 deckt problemlos alle Stockwerke ab, auch durch die Betonmauern. Damit wÃ¤re fÃ¼r mich zumindest belegt, das 802.11ac tatsÃ¤chlich eine bessere Reichweite hat als seine VorgÃ¤nger. Und Strom fÃ¼r den zweiten Router spare ich auch noch. Fein.
Ever since some upgrade of my Ubuntu workstation it would took forever (10-15 seconds) to login to remote hosts using ssh. The solution is quite easy. Edit /etc/ssh/ssh_config and make sure you have set the following options:
Since I made these changes ssh logins again work in no time.
Today seems to be one of these days again. Just when I started working on some projects my wireless router died. LuckilyBelkin has sent me a PlayMax router just a couple of days ago so I decided to use that one as a drop-in replacement. Installing the hardware was a breeze since all cables were already attached. Connecting to my home network only required to plug in one additional network cable. I skipped configuration and used the credentials provided on the card attached to the router to connect to the wireless network. No problems there either so I was up and running again in under five minutes. Nice: from my first judgement the PlayMax has an enhanced coverage zone. Signal strength on my Macbook Pro is a lot better than with the old WLAN router. So my first impression is very positive, we’ll see how it plays out in the long run.
Two things I’ve always missed on the ReadyNAS were a DNS server to serve my local network and a fully fledged DHCP server allowing me to assign IP addresses to my machines based on their MAC address. Dnsmasq can do both and more. It even integrates a TFTP/BOOTP/PXE server to boot diskless machines off the network. So I dived into the realms of add-on programming again and baked some add-ons ;)
One popular method to connect Tomcat or JBoss to the Apache web server is using mod_proxy_ajp. This of course works very well except for the case where you want to pass some environment variables to the backends. This is especially true for those who want to implement a 404 error handler using Java or other languages backed by Java. A common request is to be able to pass the values of the REQUEST_… variables defined by Apache to the error handler. While the AJP13 protocol would actually allow for that to happen, mod_proxy_ajp doesn’t offer that functionality. Luckily it’s quite easy to patch the functionality in. All you need is the Apache source code. Download and unpack, then open the file modules/proxy/ajp_header.c in your favorite text editor. Look for this code snippet: Continue reading →
When running my preferred proxy cache Varnish on Linux I realized that I couldn’t start enough threads on heavily accessed systems. As I found out, reducing the stack size is the key to get to the number I need. Oh well, if everything would be easy, I wouldn’t get paid I guess ;) Continue reading →
I work with web sites for a living. I give them a place to live, I trash them when they’re no longer needed and I also move them. And believe me, moving a site is the trickiest of the jobs. But in all of my professional life, I’ve never ever seen a blunder like this (output shortened for brevity):
crow:~$ dig developer.lotus.com
; < <>> DiG 9.6.0-APPLE-P2 < <>> developer.lotus.com
;; QUESTION SECTION:
;developer.lotus.com. IN A
;; ANSWER SECTION:
developer.lotus.com. 127 IN CNAME 220.127.116.11.
18.104.22.168. 0 IN A 22.214.171.124
Really. Did they outsource the last thinking person in their networking department? Ok, maybe they fixed it and the change just hasn’t trickled down. So let’s try a different approach (again, shortened:)
After installation the server will start immediately. However, it will take some time for the server to actually sync time and date with the official time sources. So it takes about 15 to 20 minutes until any client on your network can actually sync its time with the time source on the ReadyNAS.
Have fun with the tool and remember: Works for me, ymmv.
Finally being bothered enough by always having to connect my USB scanner to yet another computer, I decided to bring the SANE backends to the ReadyNAS. As a result, I proudly presend sane-backends_1.0.20-readynas-0.1.0. Using this addon will add support for a vast variety of USB scanners to your ReadyNAS.
To use the scanner attached to your ReadyNAS, you’ll also need a compatible SANE frontend. Those are available for Linux and Windows (XSane) as well as for Mac OS/X (TWAIN SANE, even already with a version for Snow Leopard).
I just finished creating two Addons for the ReadyNAS Duo, NV, NV+, 1100 and X6 that allow you to host SVN repositories. The first obviously is Subversion itself. This addon includes all the subversion command line tools and also adds support for accessing the repositories on your ReadyNAS through the browser interface.
The second addon is WebSVN. In addition to browsing the repositories in a much nicer interface than SVN itself provides, this modified version also allows the creation of new repositories for authenticated users. To use WebSVN, PHP support has to be installed on the ReadyNAS which can be achieved by using the PHP_1.1.bin from Readynas.com.
As always: Works for me, ymmv. If these addons break your ReadyNAS you own the parts.
Ah, and before you ask: Yes, versions for the Intel based ReadyNAS products are to come shortly. Don’t hold your breath, though.
At Backblaze, we provide unlimited storage to our customers for only $5 per month, so we had to figure out how to store hundreds of petabytes of customer data in a reliable, scalable wayâ€”and keep our costs low. After looking at several overpriced commercial solutions, we decided to build our own custom Backblaze Storage Pods: 67 terabyte 4U servers for $7,867. In this post, weâ€™ll share how to make one of these storage pods, and youâ€™re welcome to use this design.
Wow. If I had the money to spare, I’d definitely go and try to build one myself.
We all love WordPress. But, honestly, it’s everything but fast. An easy way to speed it up a good deal is to make it use memcached for storing some of it’s data. And doing this is actually easier than one might think. There are some pre-requisites:
While re-installing the server hosting this site yesterday I ran into an interesting problem: The inital run of
on booting up the Linux image provided by my hoster would would report a file system inconsistency and wait for either the “root” password or a press of CTRL-D.
Since I didn’t know the “root” password (this is only supplied after installation has finished) and CTRL-D resulted in a reboot with the same result as before, I was stuck in a catch 22. Or so it seemed.
Luckily I had access to a serial console. So I could interrupt the boot process and edit the grub line with the kernel options. There adding the statement
made the Linux kernel skip the inital fsck run and voila, installation completed successfully.
To give you the whole picture: All I had to was to change this
Die ZyXEL Modelle MGS-3712 (1180 Euro inkl. MwSt.) und MGS-3712-F (1099 Euro inkl. MwSt.) sind speziell fÃ¼r den Aggregations-Bereich von Fiber to the Building (FTTB) Infrastrukturen konzipiert. Beide Versionen verfÃ¼gen Ã¼ber jeweils 12 Gigabit Ports. Beim MGS-3712 (786 Euro inkl. MwSt.) sind es 8x Kupfer und 4 Dual Personality Ports fÃ¼r den alternativen Anschluss von SFP Glasfasermodulen.
Noch 10 Zeilen mehr und man hÃ¤tte wahrscheinlich Geld fÃ¼r den MGS-3712 bekommen, wenn man ihn nimmt ;)
Network equipment vendors are getting a little buzzword-crazy when it comes to one of the biggest buzzwords today – “cloud computing” – and suddenly all of their switches and routers have “cloud” capabilities. Give me a break.