Been too long since I’ve posted anything on this blog. What I have I been up to? Well, I sold the Archos 101 tablet in order to get a Viewsonic gtablet on the cheap from woot.com. It’s much more powerful than the Archos and actually has a dual core tegra2 processor in it. I’ve nuked the default version of android and installed Cyanogenmod 7 on it. It works very well and I’ve enjoyed using it every day. I even got the Netflix streaming application working on it without any issues. This year I’ve decided not to go to OLF (Ohio Linuxfest) for a couple reasons. First off I’ve been to the conference multiple times already. It’s a great show that I highly recommend people to attend if you’re interested in Linux and Open Source. Another reason I’m not going is that my proposed talk was rejected. While I enjoy going to Linux conferences and just hanging out I feel like I’ll get more out of the experience if I actually contribute with a talk. Finally I plan on attending the Maker Faire in NYC the weekend after OLF. I’ve heard so many good things about the Maker Faire (both in San Francisco and NYC) over the years that I feel I really need to finally check it out. I’m trying to get my kids interested in science and what better way than bringing the whole family along. Let me know if you plan on going and perhaps we can get together for a bit.
Archive for the 'Linux' Category
Bitten by the rsync bug? I was. Apparently in the new RHEL 5.7, and I am sure the RH clones like CentOS, Scientific Linux and ClearOS(?) as well, there is a bug in rsync when you use it with ssh transport like so:
rsync -avz -e ssh remotehost:/data /data
The fix is to make sure to append a username to your host and then it magically starts working properly again.
rsync -avz -e ssh username@remotehost:/data /data
I have had to spend a lot of time this week on my netbook. Normally I really dig the Linux Mint background, but the light background of Mint 11 on my little netbook was just too bright and annoying to me for some reason. So, I set out to find something a little darker.
Where do you go for a really great wallpaper? Well, my friend Bill just happened to post a link to probably the greatest wallpaper site I have ever seen at http://wallbase.cc/. Warning! You can easily lose several hours looking through wallpapers there.
Changing your background in Mint or any other Gnome 2 using distribution is pretty straight forward. You right click on your desktop, select “Change Desktop Background” and then pick the one you want. You also have the ability to add other wallpapers not already in your background collection with the “add” button.
Changing the login screen to match is a different matter altogether. I have found that the easiest way to accomplish this is to install http://ubuntu-tweak.com/. This is a great little package that will let you change all kinds of hard to find settings not the least of which is the login screen background. On ubuntu-tweak, youy simply select login settings, then unlock, click on the old wallpaper, surf to and choose the new one you want, then quit.
Lastly, there is changing the “lock screen” wallpaper. This is the screen you are presented with when you unlock your computer after locking your session with a
sudo gconftool-2 –direct –config-source xml:readwrite:/etc/gconf/gconf.xml.defaults –set /desktop/gnome/background/picture_filename –type string `gconftool-2 –get /desktop/gnome/background/picture_filename`
(note that the above command is all 1 line)
And that’s it folks! Again, this should all work on any Gnome 2 desktop.
So I stopped by the local BestBuy store and played with the Motorola Xoom for a bit. Is it a really nice Android tablet? Absolutely. Is it nicer than the Apple iPad? Of course it is. It’s not even close. Is Honeycomb beautiful and a major leap for Android into the world of tablets? Yes, it’s really really is nice. Is the Motorola Xoom worth $799 and being locked into data plan? No, it isn’t. If Motorola wants to seriously challenge Apple they need to offer a wi-fi only version and drop the price by $200. End of story. Honestly if you don’t want an Android tablet that will require selling your children and body to science there are far better choices. Amazon has the the Archos 101 for $294. They also have the Archos 70 for $270. You buy also buy a Barnes & Noble Nook Color for $200 until March 3rd. You can install Cyanogenmod and make it a totally kick ass Android tablet and not just an ebook reader. Another option is get a Samsung Galaxy Tab for $499 (without contract) or $249 (with a 2 year data contract). Save your money and let the price of the Xoom come down. There is going to be a flood of Android tablets in the next year. Prices will drop. There will be many many options. In fact there already are.
This is somewhat of a reprisal of some thoughts I shared on a recent episode of the LinuxLink TechShow.
I have been asked many times about being a Linux admin. After a few years of walking the walk and being in on a lot of interviews, I have compiled a few mental notes and thought I would share…
- Get a cert.
I have been doing Linux for a LONG time but I never had so many job offers until I got my RedHat cert and put it on LinkedIn. Once that happened I get, some weeks, upwards of 5 job offers per week. Seriously. These offers are also local – not like people are calling me to move out of state or even out of the area. The jobs are out there folks. Linux people are currently on the hot list. Just do it right and you should be a shoe in.
- Know your stuff.
Here’s the deal. You MIGHT run into a company where you can snow them into thinking you are a serious Linux guy even though you don’t know how to tell what directory you are in on the command line, but it sure won’t be MY company. I ask potential candidates lots of questions – ones that I am convinced that anyone that *actually uses Linux* should know. Make sure that you do. You should know all kinds of common Linux things down absolutely cold and this includes things like common userland commands, problem diagnosis and resolutions. If you don’t know the fix to a problem, you should be able and prepared to demonstrate that you can quickly find the correct answer / resolution.
- Don’t rely on the gui.
I used to think this was a given but after a dozen interviews it bears mentioning. You *cannot* correctly administer a hundred servers if you need to rely on gui tools. They may be handy in a pinch, but they are wildly inefficient. On the same tolkin, you should be familiar and comfortable with at least basic scripting. One of the questions I generally ask is if another administrator left your company, how would you change the root password on 100 servers in a hurry?
- Do be familiar with Desktop Linux.
Although I think it’s extremely important to be command line savvy on the server end of things, I am also convinced that a Linux guy should be comfortable with using it on the desktop as well. It always strikes me as strange when I ask a Linux guy what kinds of computers he has at home and what he uses them for and he (or she – it’s just a figure of speech) says they have a windows laptop that they only use for browsing the web and email.
- At least feign interest.
In my opinion, a Linux system administrator should be interested in Linux and system administration. Things like playing at home with different linux distributions, running your own home server, setting up , learning about and trying different Linux services are all big plusses.
- Don’t BS on your resume (or resume inflation).
A friend of mine I work with and I have this theory that a person’s actual skill level with Linux is conversely proportionate to the size of their resume. Actually, this goes back to that “Know your stuff” rule as well. Put the relevant things you know on your resume and *actually know them*. Trust me, I will ask you technical questions about the things you list on your resume and I *will* find out if you are lying. Inflated resumes may impress H.R. people but not the people who actually have to weed through them.
- Shake hands like you mean it.
When you come for an interview, if you offer to shake hands or take an offer to shake a hand, actually do it. Nothing weirds me out more than someone giving me one of those limp wristed, pantywaist, palm tickle handshakes. Grip my hand like you mean it and give it a good shake like you are happy to be there.
- Be genuine.
Don’t try and be someone you are not during the interview. Be yourself, relax a little, be honest. Don’t be overly cocky, snarky, apologetic or overtly eager. Also, try and dress decently and speak well.
That’s all I can think of right now – Knock ‘em dead!
Last night on the TechShow I was asked about providing some info on a decent default server build. Here are some quick notes to get people going. Adjust as necessary.
Just for ease, here, lets assume you are installing CentOS 5, a nice robust enterprise class Linux for your server needs.
CentOS 5 / RHEL 5 / Scientific Linux, etc., does a really great job picking the defaults, so sticking with those is just fine and has worked well for me on literally hundreds of servers.
- I let the partitioner remove all existing partitions and chose the default layout without modification.
- Configure your networking appropriately, make sure to set your system clock for the appropriate timezone (no I do not generally leave my hardware clock set to UTC).
- When picking general server packages I go for web server and software devel. I do not, generally, pick virtualization unless there is a specific reason to. I find that the web and devel meta server choices provide a robust background with all the tools I need to set up almost any kind of server I want without having to dredge for hundreds of packages later on.
- The install itself at this point should take you about 15 minutes depending on the speed of your hardware.
- Once installed, reboot the server and you should come to a setup agent prompt. Select the firewall configuration. Disable the firewall and SELinux completely (trust me here). Once that is done, exit the setup agent (no need to change anything else here), login to the machine as root and reboot it. This is necessary to completely disable SELinux.
From this point on it’s all post install config…:
- Add any software repositories you need to.
I not only have my own repo for custom applications, but also have a local RedHat repo for faster updates and lower network strain/congestion.
- Install your firewall.
I use an ingress and egress firewall built on iptables. While mine is a custom written app, there are several iptables firewall generator apps out there you can try.
- Install your backup software.
Doesn’t matter if this is a big company backup software like TSM or CommVault, or you are just using tar in a script. Make sure your system is not only being backed up regularly, but that you can actually restore data from those backups if you need to.
- Add your local admin account(s).
Don’t be an idiot and log into your server all the time as root. Make a local account and give yourself sudo access (and use it).
- Fix your mail forwarding.
Create a .forward file in your root directory and put your email address in there. You will get your servers root emails delivered to you so you can watch the logwatch reports and any cron results and errors. This is important sysadmin stuff to look at when it hits your inbox.
- Stop unnecessary services.
Yes, if you are running a server you can probably safely stop the bluetooth and cups services. Check through what you are running with a “service –status-all” or a “chkconfig –list” (according to your runlevel) and turn off / stop those services you are not and will not be using. This will go a long way toward securing your server as well.
- Install OSSEC and configure it to email you alerts.
- No root ssh.
Change your /etc/ssh/sshd_config and set “PermitRootLogin no”. Remember, you just added an admin account for yourself, you don’t need to ssh into this thing as root anymore. Restart your sshd service after making the change in order to apply it.
- Set runlevel 3 as default.
You do not need to have a GUI desktop running on your server. Run the gui on your workstation and save your server resources for serving stuff. Make the change in /etc/inittab “id:3:initdefault:”.
- Fix your syslog.
You really should consider having a separate syslog server. They are easy to set up (hey, Splunk is FREE up to so much usage) and it makes keeping track of whats happening on multiple servers much easier (try that Splunk stuff – you’ll like it).
- Set up NTPD.
Your server needs to know what time it is. ‘Nuff said.
- Install ClamAV.
Hey, it’s free and it works. If you do ANYTHING at all with handling emails or fileshares for windows folks on this machine, you owe it to yourself and your users to run Clam on there to help keep them safer.
- Do all your updates now.
Before you go letting the world in on your new server, make sure to run all the available updates. No sense starting a new server instance with out of date and potentially dangerous software.
- Lastly, update your logbook.
You should have SOME mechanism for keeping track of server changes, whether it be on paper or in a wiki or whathaveyou. Use it RELIGIOUSLY. You will be glad someday you did.
I wanted to try out Subsonic, so I really needed to put together a new machine to play with it a bit. As a RL System administrator, some things carry over into my home computing environment, and paranoia is one of them. I just *have* to test things outside of my “production” servers at home too. Since I run my servers in a virtualized environment, this shouldn’t be too much of a problem.
I run ESXi at home for my virtualization platform, and the norm there is to use virtualcenter (or the vic) to create and manipulate VMs. The problem there is I am just not a Windows fan (no kidding). I had gotten around this problem initially by creating a VM on VMware Server (running on Linux) and then using VMware Converter to move that VM to my ESXi machine. This time, I did a little more digging on the subject of using the command line to create those VMs natively and I actually found some great information that let me do just that. What I found was these two links that contain all the information I needed:
ESXi – creating new virtual machines (servers) from the command line
Without rehashing a lot of the detail provided in those two sites, the basics are using vmkfstools to create a disk image for you to use and then building a small minimal vmx file with enough info in it to get things going. To do the install, make sure have your vmx start an iso image from the cdrom drive and turn on vnc for the box. From there it’s quite easy to get an install working.
The server I decided upon installing is CentOS 5.5. I chose the standard server install and the only things that were required to get Subsonic working on it were:
yum install java-1.6.0-openjdk
and then to download and install the rpm from Subsonic’s website. A little later on I found that Subsonic would not stream my ogg files and that was easily fixed by:
rpm –import http://apt.sw.be/RPM-GPG-KEY.dag.txt
rpm -Uvh rpmforge-release-0.5.2-2.el5.rf.i386.rpm
yum install lame ffmpeg
After all that, pointing your web browser to http://
Early last week I had another burst of reading activity on my Kindle 3. Reading for me tends to come in spurts when the rest of my life doesn’t interfere and it had been a while. I loaded up the Kindle with some new goodies (Sh*t my dad says is hilarious, btw) and started peeling through not only the books but also the menus, setting things up just the way I like them.
RANT: As a side note here, why the heck are collections so freaking difficult to setup? I mean come on Amazon. Make them work by directory structure or something easy, or at least fix it so that when you add to collection, you are only shown books not already in another collection by default. OK, rant done
Anyhow, as I was reading and setting up different collections, etc. I noticed a familiar recurring problem. The short history is when I got my Kindle 3 I noticed every so often the e-ink would not fully display, but only display VERY faintly. I called Amazon and they had me update the firmware but ut was really hard to tell if that fixed it as it was not a constant thing. Queue up last week and I notice this a LOT more. Not only while reading the books, but now in the menus, etc.. So, I called Amazon right up as they instructed me to do the last time I noticed this. They IMMEDIATELY sent me out a replacement. I mean I had it the NEXT day, during a snowstorm. There was no arguing, no listening to some low end tech worker flip pages on the other end of the phone, no shipping or return costs, no hassle whatsoever. THIS is what customer service is all about and it’s easy to see that Amazon stands behind it’s products. This is why I will always recommend the Kindle. I don’t know what the other guys service is like, but Amazon is absolutely tops every time I have had to deal with them.
Shortly after I got my new Kindle (read hours) I got horribly sick (sinus infection) and have been that way for 4 or 5 days now. During my occasional bouts of lucidity and while waiting for the NyQuil to kick in again I was reading through my facebook posts and noticed Tom Higgins mentioning that he was enjoying using Subsonic, which is a new (to me anyway) software that manages your music collection for you. It’s a server side app with some seriously nifty clients you can run on you android phone, which made it catch my eye. I have (and still do for now) been using Kplaylist for quite some time and I really like it, but, hey, nothing wrong with checking out new things, right?
Well, the thought of me trying out some new music collection software got me looking at my music collection. You know what this is like. I have been hanging on to my music in digital form for better than 10 years, so, it’s substantial / sizable, in different formats, mixed up, formatted and named badly, bad mp3 and ogg tags, etc.. What’s a guy to do? Well, I searched around a bit and found a whole lot of programs for Linux that will let you manually fix tags. Ick. With thousands to do I kept searching. I found a bunch of programs for windows and mac that will help you reorganize and fix your collection, and, eventually, I found ONE that will do the same on a Linux box. It’s name is MusicBrainz Picard I have been using it here and there (still sick) for a couple days now, sicking it on a directory of my music collection here and there. It sure beats doing this all by hand! It’s not perfect software by any means, but it sure will be a timesaver compared to the alternative and the more people that use it and update those databases, the better it’ll work. Check it ut, I think you’ll like it!
Some days things just go right. It’s been a while since that happened to me, hence the lack of posts lately. Well, that changed tonight…
I decided it was high time to get a new printer. I have been using used HP LaserJets for years and my last, a LaserJet 5 was finally starting to show some wear, not to mention hogging enough electricity to power a small city. I have also endured about 4 years of complaints that we didn’t have a color printer.
I checked out the stock of some local electronic stores online and spent an hour or two googling whether this or that model printer wold work under Linux. I actually wanted to grab the same printer Dann bought, just because I knew that one would work, however, I couldn’t find a local source. I settled on buying an Epson Workforce 520 from the local BesyBuy.
Setup was an absolute breeze. I unpacked it, followed the setup instructions to add it to my local wireless connection via the printer’s control panel. Then I headed to openprinting.org to grab the driver and installed it. It’s just a deb (or rpm) package so it was a click or two to install. After that I headed to Linux Mint’s printer config utility, told it to search for network printers and it was found and installed automatically with no fuss, no muss whatsoever.
Everything works, and I mean everything. This is one of those multifunction printers that not only prints, but faxes (actually I haven’t tried that and probably won’t), copies AND SCANS! After my initial test print, I fired up Mint’s “Simple Scan” which scanned a document I had on the printer easily and perfectly. I was amazed!
I believe I may have found the perfect wireless printer/copier/scanner to run under Linux Mint (yes, it’s wireless too, did I mention that). I know Linux printing has come a long long way, but this was trivially easy. If you are looking for a great new printer addition to your Linux setup, this is it!