Best of Technical Support
Can I create my own IP header, with a new static field of 32 bits, and send it to a destination host?
—Muguntha Kumar, mugunth_kay@rediffmail.com
Sure. Look at sendip for a programming example: www.earth.li/projectpurple/progs/sendip.html.
—Marc Merlin, marc_bts@merlins.org
What does process state D mean in the output of ps? Why doesn't the system allow root to kill processes with state D? What should one do if these processes are consuming a lot of system resources, which need to be released for use by other processes?
—Ankit Doshi, doshiaj@yahoo.com
State D means the process is in uninterruptible sleep—sleeping, waiting for something to happen, but it cannot be interrupted, even by kill -9. Sometimes the D process is trying to access remote filesystems that are unmounted or no longer available. If that is the case, use the soft option to mount.
—Felipe Barousse Boué, fbarousse@piensa.com
At bootup I get:
lib/modules/2.4.9-34/kernel/drivers/crypto/ bcm/bcm5820.o:init_module Cannot locate memory.
I am not able to see any fault. Is this significant?
—George Robertson, grobertson29@earthlink.net
This is the driver module for Broadcom Cryptonet BCM5820. If you do not have this device, you can ignore this error.
—Usman Ansari, usmansansari@yahoo.com
I was trying to query all of the installed RPMs on my computer, so I used rpm -qaR. However, this gave me a lot of information that isn't user-friendly. I read a section in Maximum RPM about the --queryformat option. Now, I'm using this:
rpm -qaR "%{NAME}[%-8{REQUIRENAME}\n]"
The results, though, are exactly the same as those from the previous query. Anybody have any ideas how to make the output readable/usable?
—Joe, joeslapnuts@yahoo.com
You need to include --qf or --queryformat immediately before your query format string. Use rpm --querytags to list all the possible tags in the version of RPM you have.
—Don Marti, dmarti@ssc.com
I have Red Hat 7.2 on a Gateway PC with an ATI RADEON 8500. I installed XFree86 on a number of systems, but I'm stumped with this one. Initially, I set up /etc/X11/XF86Config-4 to use the RADEON driver and according to the log, it loads that driver as well as the ATI driver and a bunch more. All appears to be fine until the end; then it says:
(II) Primary Device is: PCI 01:00:0 (EE) No devices detected. Fatal server error: no screens found
Any ideas?
—Chris Carlson, cwcarlson@cox.net
To rule out configuration errors, try using an /etc/X11/XF86Config-4 generated by Xconfigurator.
—Christopher Wingert, cwingert@qualcomm.com
You may need to upgrade your XFree86 to 4.2 (stock Red Hat 7.2 comes with XFree86 4.1), which includes support for your ATI RADEON. See www.xfree86.org/4.2.0/Status6.html#6.
—Felipe Barousse Boué, fbarousse@piensa.com
I encountered a corrupted / filesystem last June. I tried to repair the filesystem (running fsck) but was unable to recover it, so I re-installed Red Hat 7.2. After a month, the same thing happened. Now we are trying to find out if this problem is hardware- or software-related. How can I find out?
—Bing, bingcruz@yahoo.com
If you have a stock Red Hat box (i.e., no custom software), it is unlikely to be the RH distribution. I would suspect your hard drive is about to fail.
—Christopher Wingert, cwingert@qualcomm.com
Are you shutting down correctly? If you hit the power switch while a lot is happening, that could corrupt two installs in two months.
—Don Marti, dmarti@ssc.com
Check your logs, especially /var/log/messages, for any indication of disk or disk controller failures or mishaps. If you're re-installing Linux, run the “check for disk bad blocks” option, which makes a more in-depth check of your disk.
—Felipe Barousse Boué, fbarousse@piensa.com
It's almost certainly the hardware. Other possibilities include an overclocked CPU or motherboard, turning the power off without shutting down, overheating and so on.
—Ben Ford, ben@kalifornia.com
1) Next time you install, make two root partitions, one called / and one called /safe. Copy the content of / to /safe every so often, and make sure LILO or GRUB is able to boot from there. That way you won't be dead in the water if this happens again. 2) It's hard to say if it's hardware or software without more information. Consider switching to a journaling filesystem, such as ext3, so your system can recover more easily if you have problems.
—Marc Merlin, marc_bts@merlins.org
Realizing the promise of Apache® Hadoop® requires the effective deployment of compute, memory, storage and networking to achieve optimal results. With its flexibility and multitude of options, it is easy to over or under provision the server infrastructure, resulting in poor performance and high TCO. Join us for an in depth, technical discussion with industry experts from leading Hadoop and server companies who will provide insights into the key considerations for designing and deploying an optimal Hadoop cluster.
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| Dynamic DNS—an Object Lesson in Problem Solving | May 21, 2013 |
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| Making Linux and Android Get Along (It's Not as Hard as It Sounds) | May 16, 2013 |
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| Home, My Backup Data Center | May 13, 2013 |
| Non-Linux FOSS: Seashore | May 10, 2013 |
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Enter to Win an Adafruit Pi Cobbler Breakout Kit for Raspberry Pi

It's Raspberry Pi month at Linux Journal. Each week in May, Adafruit will be giving away a Pi-related prize to a lucky, randomly drawn LJ reader. Winners will be announced weekly.
Fill out the fields below to enter to win this week's prize-- a Pi Cobbler Breakout Kit for Raspberry Pi.
Congratulations to our winners so far:
- 5-8-13, Pi Starter Pack: Jack Davis
- 5-15-13, Pi Model B 512MB RAM: Patrick Dunn
- 5-21-13, Prototyping Pi Plate Kit: Philip Kirby
- Next winner announced on 5-27-13!
Free Webinar: Hadoop
How to Build an Optimal Hadoop Cluster to Store and Maintain Unlimited Amounts of Data Using Microservers
Realizing the promise of Apache® Hadoop® requires the effective deployment of compute, memory, storage and networking to achieve optimal results. With its flexibility and multitude of options, it is easy to over or under provision the server infrastructure, resulting in poor performance and high TCO. Join us for an in depth, technical discussion with industry experts from leading Hadoop and server companies who will provide insights into the key considerations for designing and deploying an optimal Hadoop cluster.
Some of key questions to be discussed are:
- What is the “typical” Hadoop cluster and what should be installed on the different machine types?
- Why should you consider the typical workload patterns when making your hardware decisions?
- Are all microservers created equal for Hadoop deployments?
- How do I plan for expansion if I require more compute, memory, storage or networking?




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