list running processes in linux
i have always used
# ps aux
for listing system process information. but recently i wanted to list more specific memory and processor details in snapshot mode of the entire system. the command # top is great for monitoring a live system, but if you want to be able to store snapshots of processes for logging, # ps is the command to start from. i was led to the -u switch and have been using the following version:
# ps uxa
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
Ubuntu 11.04
I am loving the newest release of Ubuntu – it is fastest, leaner and more user friendly than ever. I also really like the docking bar on the side – all of the ease of access that previously was in the Ubuntu Netbook Remix, but with an intelligent autohide feature.
Some of the complaints that I have about this version of Ubuntu Linux are:
- Nvidia graphics support has taken a step backwards, drivers are less stable, and you are encouraged to use the native linux driver, which is not as advanced as Nvidia’s
- The Start Menu – this new start menu has a great search feature and usually is able to find what you are looking for, but i’m stubborn and old fashioned and i really miss being able to open a fulll listing of my apps (i don’t always know what I’m looking for when I go to my menus)
- Updates introduced issues – on two machines that are running the desktop version of this Ubuntu 11.04 hard crashes were introduced by system updates. One of them updated the grub files on a hard drive that was not the boot drive, and then removed the MBR records from the boot drive, this ultimately lead to the users data becoming corrupted due to a reboot link it introduced. The other user lost X (graphical mode) and was basically unable to dual screen (with Twinview) for a few days.
None of these issues are super-major, but they all were setbacks in the new version of Ubuntu. I guess that in the open source world when a person installs a bleeding edge software product, one must expect it to still be bloody
Don’t Forget About Live CD’s
So I’ve been troubleshooting this computer. It’s a Windows XP machine, relatively new, decent hardware, all SiS integrated components. Video works fine, USB works fine all SATA components are fine. No matter what I do I can’t get the network card to work –> fails to obtain a lease, static IP configuration doesn’t allow me to ping my local gateway. I have tried all my tricks, hard coding the MAC address into a static lease in the router, setting up both DHCP and a matching static in the machine. The network cable is good, DHCP works fine on other machines on the same cable. Also, the HD audio is not producing any noise either.
I’ve ran my personal tools, (ComboFix, CCleaner, Advanced System Care and Malware Bytes Anti-Malware) and they found a few things but nothing major. The customer’s machine currently has Spyware Doctor installed and it may have interfered with ComboFix, but I did disable it. I even uninstalled the NIC and rebooted (there were no previous drivers to roll back to). After exhausting these resources onsite, I asked if I could bring it back to the office for diagnosis. My initial gut told me it was a software issue, but at this point I’m leaning toward failed hardware.
Why I didn’t think of it while I was onsite I am not sure, but it occurred to me that I could runfull hardware tests from a Live CD – I downloaded and burned to disc the most recent CD-sized Knoppix (6.2.11) – a great tool for trying out hardware, trying out Linux and just all around access to things Winbloze just doesn’t allow.
Sure enough I booted Knoppix and was instantly online on the same network card that ethernet would not work in Windows. Software issue.
I’ve since booted the AVG Rescue CD and was scanning overnight, and have burned the newest SiS network and audio drivers to disc for a reinstall. I am not sure what the final issue will be proven to be, but the point is, don’t overlook live Linux CD’s as part of routine testing. It can save valuable hours of troubleshooting and truly isolate the problems to hardware or software.
Installing Zint Barcode Generator in Ubuntu 10.04
download from sourceforge http://sourceforge.net/projects/zint/
$ sudo ap-get install g++
$ sudo apt-get install cmake
$ sudo apt-get install libqt4-dev
$ cd /usr/local/src
$ sudo tar zxvf /home/{username}/Downloads/zint-version.tar.gz
$ cd zint-version
$ sudo cmake .
$ sudo make
$ sudo make install
DNS Server Basics
A description of DNS server functionality, and the steps required to remove a domain from one.
What is a DNS server?
DNS (Domain Name System) is the protocol that is used by computer networks to translate IP (Internet Protocol) addresses into domain names. A DNS server is a computer specifically set up to be queried by other computers for the IP-to-domain translations. There are many kinds of records that can be associated with a specific domain name, but the ones of primary interest for this document are A records (used to point websites to the computers that host them) and MX records (used to point email to their appropriate server). The result of a DNS query is a resolved IP address. Every time a web page is loaded or an email is sent, at least one DNS query has resolved by a DNS server.
What is required to remove a listed domain?
For a DNS server to stop answering for a domain, records associated with the specific domain must be removed from the list of records the DNS server has. In most situations, the minimum numbers of records associated with a domain for a website and email to function is 4. One record for each of the following:
1. A record domain.com XXX.XXX.XXX.XXX (ip address)
2. A record www.domain.com XXX.XXX.XXX.XXX (ip address)
3. MX record domain.com {name of email server} {priority 1}
4. MX record domain.com {name of email different server} {priority 2}8
How can having incorrect DNS entries affect domain and email queries?
When a potential contact sends an email to a company with a hosted email service ({user}@domain.com), the email leaves the client machine (by email client such as Outlook, or web client such as Gmail) and arrives at their email server for processing. First, the email server checks itself to see if it is the destination. If it is the destination server, the email gets delivered to the appropriate domain and account. Otherwise, the email server then performs a DNS query and resolves the address of the hosted email server and delivers the message to it.
When a queried server does not answer for a domain, it should return a result of Unknown or Failed. When a queried server knows the result, it returns the requested record type.
Root on comet
So I used z4root to exploit my t mobile comet and gain root access, used setcpu to enable frequency scaling to improve battery performance and rebooted. Then I mounted the filesystem read write and removed telenav and a bunch of other bloatware. SGS toolbox, astro file manager, autorun manager, root uninstaller, app2sd, superuser, advanced task killer and a few other tweaks and I am averaging 54 mb free of ram on boot. When I purge everything extra but leave the phone fully in tact, I reach up to 72 mb free. Seems pretty awesome considering the annoying apps are gone, it runs faster, and the battery life has drastically improved. I hope we start to see more manufacturers enabling cpu frequency scaling in the future so we the consumer dont have to risk our new phones safety for this must-have feature.
