My boss, Aaron Howard, has started a new blog about networking, called Core Flow, which will focus on the implementation of the new Enterasys K-Series switch that will service students living in our residence halls starting this fall, as well as other networking, such as the Juniper/Trapeze wireless gear we use on campus.
As I know a lot of people have received new Amazon Kindles lately for the holidays, and have probably fallen in love with them as much as I have over the last six months of owning one, I thought I'd compile a few tips about alternative ways of getting content on them. Certainly, you can buy your eBooks all from Amazon, though there can be advantages from getting them elsewhere too, especially if it saves you money!
One of the ways you can save a few bucks is by using the excellent free software package called Calibre to load content you already own on your Kindle. Amazon has a nice service where they will convert PDF and Word documents, among other formats, and send them to your Kindle, but they charge by the megabyte for the data they're converting for you. If you use Calibre, and just plug your USB cable into your computer, you can upload eBooks and other content for free, and cut out the middle an. Calibre is available for both Mac and PC, and it's a great app!
Another great source for eBooks is Baen, the science fiction publisher. If Sci-Fi isn't your cup of tea, then this probably won't interest you, but the Baen Free Library has an ever-changing collection of totally free and legal eBooks for you to download for your Kindle. They started this program at the urging of some of their authors, to help generate interest in paper sales of catalog titles, as well as in the hopes that if you read one book by the author for free and love it, you'll purchase subsequent books.
Baen also sells many other eBooks via their WebScriptions site, including many titles that simply aren't available via Amazon for the Kindle, and they're usually at a much lower price. Another nice feature of the Baen books is that they don't use any DRM on their eBooks, so you'll always be able to read them, move them to another device, or loan them out to a friend.
Friends are another excellent source of Kindle content, as many titles can now be lent to a friend via Amazon's web page. You just need to enter a valid email address to send the eBook code to, and then that Kindle owner can have the book installed on their Kindle. It's important to note, however, that not all Kindle books on Amazon can be lent, as it's up to the publisher to enable that feature. Also, a given book you own can only be lent once, and only for a period of two weeks! Make sure the person you're lending the book to will have time to read it, and REALLY wants the book, before you use up your one lending period on them.
This idea has also been extended to the Kindle Lending Club online, where users can swap their "lends" with each other, giving you access to far more titles than you could get from your friends.
I'm hopeful in the future that libraries will implement a way to check out eBooks on the Kindle too. They have the ability to do it for some other platforms, and while the DRM can be removed to let the content work on a Kindle, it's something you need a computer geek to set up.
As I’m in the market for a new cell phone and carrier, after being with Sprint (disclosure: I’m a Sprint shareholder) for 9.5 years, I did some comparison of the various 3G coverage maps of Iowa, and here they are. You can click on the maps for larger versions of many of them:
First up, iWireless. Formerly known as Iowa Wireless, they’re the closest thing we have to T-Mobile here in Iowa. Their 3G coverage is pretty weak, and is represented by the pink color on the map. Davenport, Cedar Rapids, Cedar Falls/Waterloo, Des Moines, Ames, Council Bluffs, and Iowa City are covered, and really nowhere else.. Their service prices are good, but their phone selection tends to lag T-Mobile proper by quite a bit, and if you venture outside those cities, you’re going to be on Edge or even worse, GPRS a lot of the time…
Next up is AT&T. I have two maps for them, the first is their current map, the second is the coverage they plan to have on 3G by the end of March. Cedar Falls & Waterloo went live on 3G sometime yesterday, so the map appears to be coming true. On the first map, 3G is the dark blue. On the second (future) map, current 3G is dark blue, future 3G is light blue, sorry it’s so tiny!
Third is Sprint. As I mentioned, they’re my current carrier, and cover most of the major metropolitan areas with 3G (the dark orange), though for some reason they continue to ignore Fort Dodge and Mason City, among others, as well as the I-35 corridor:
Fourth is Verizon. They cover most of the state with their 3G (red) coverage, though that salmon color shows they have some holes in the northwest & southwest corners. I, personally, never go there, so it doesn’t really bother me, but I wish there was a little better coverage on US 63 north from Waterloo to Rochester, MN.
Fifth, and best, in my opinion, is regional carrier US Cellular. They cover almost all of the state with 3G as represented by the sickly green color, and when you’re not on their network, you’ll roam onto Verizon’s 3G network in most of the country. For some reason, the bottom tier of Minnesota seems to be non-3G coverage in their maps, however.
So what’s an Iowan to do? Clearly if you’re a heavy smartphone user, and you travel outside major cities, CDMA is your only real option for technology, and the best choices are Verizon & US Cellular. Sprint isn’t bad in Eastern Iowa, but really degrades elsewhere, and in rural areas. The GSM carriers, iWireless and AT&T, are really only great in the major cities, over 100,000 people, but if you don’t spend any time out in little places like Ventura, Manson, or Hanlontown, Iowa, they’d be fine. Unfortunately, I spend time in those places, and even some bigger ones, like Mason City and Fort Dodge, and I think I want 3G coverage in all of them for my next phone…
NetBackup 7 officially “supports” Ubuntu Linux 8.04, 9.04, and 10.04 for Linux clients, as seen in the Software Compatibility List but the installer doesn’t “work”.
Specifically, the problem seems to be that PBX, or Private Branch Exchange, is distributed in an RPM package along with the client. The normal shell script that installs the client kicks an error when PBX fails to install:
Installing PBX... ./installpbx: 1510: rpm: not found ERROR: Could not install VRTSpbx package Please see installation log for more details Installation log located here: /var/tmp/installpbx-1928-100810135211.log Installing PBX was unsuccessful. Aborting ...
Opening the next log reveals more:
[10-08-10-13:52:11] Extracting /var/tmp/VRTSpbx_1928/PBX.tar.gz into /var/tmp/VRTSpbx_1928 [10-08-10-13:52:11] Installing/Upgrading private branch exchange on Linux [10-08-10-13:52:11] Checking for the PBX process... [10-08-10-13:52:11] PBX process is not running. [10-08-10-13:52:11] rpm -U --nodeps --nopostun --nopreun /var/tmp/VRTSpbx_1928/VRTSpbx-1.4.0.10-10.RH_x86_64.rpm ./installpbx: 1568: rpm: not found [10-08-10-13:52:11] ERROR: Could not install VRTSpbx package [10-08-10-13:52:11] Removing temporary directory [10-08-10-13:52:11] rm -rf /var/tmp/VRTSpbx_1928 [10-08-10-13:52:11] installpbx exiting with return code: 1 [10-08-10-13:52:11] Please see installation log for more details [10-08-10-13:52:11] Installation log located here: /var/tmp/installpbx-1928-100810135211.log
As this isn’t Red Hat, rpm is not present on the system, nor would it work if it was…
With the help of the folks at Symantec, here’s what will get around this problem and help you install the client. Hopefully they’ll put this online in a tech note soon, but I’m guessing I’m not the only person who ran into this problem, so here are my notes. I am not a Linux wizard, by any means, but here are the required steps to make this work. This also requires you to install alien, a package that’ll let you install rpm packages on Ubuntu:
Get the giant 7.0 client tarball and copy it to your server. I downloaded mine from FileConnect.
gunzip NetBackup_7.0_CLIENTS_GA.tar.gz.gz
tar xvf NetBackup_7.0_CLIENTS_GA.tar.gz
cd NB_7.0_CLIENTS_GA/NBClients/anb/Clients/usr/openv/netbackup/client/Linux/RedHat2.6
sudo mkdir /tmp/pbx
sudo cp PBX.tar.gz /tmp/pbx
cd /tmp/pbx
sudo gzip -dv PBX.tar.gz
sudo tar xvf PBX.tar
sudo apt-get install alien
sudo alien -i --scripts VRTSpbx-1.4.0.10-10.RH_x86_64.rpm
(you will see lots of errors, you can ignore them)
Then start PBX on the CLIENT:
sudo /opt/VRTSpbx/bin/vxpbx_exchanged start
sudo nano NB_7.0_CLIENTS_GA/NBClients/anb/Clients/usr/openv/netbackup/client/Linux/RedHat2.6/cp_to_client
Comment out lines 1723 - 1732 by inserting a # at the start of the line (use Control-W in nano to search for PBX to help locate this):
1723 # ${ECHO} "
1724 #Installing PBX..."
1725
1726 # ${SOURCE_DIR}/installpbx -f PBX.tar.gz
1727 # if [ $? -ne 0 ] ; then
1728 ${ECHO} "
1729 #Installing PBX was unsuccessful.
1730 #Aborting ..."
1731 # exit 1
1732 # fi
Hit Control-X to save and exit.
Then execute the "install" script in /NB_7.0_CLIENTS_GA
Success!
You can then normally patch the client to version 7.01, as that won’t require you to use any RPM-based packages. I've also heard that installing version 6.5.4, then upgrading from there to 7.0 will work too, as that version of PBX will install ok, but I haven’t tried it.
Here’s an interesting issue we’ve encountered at work. This also demonstrates how useful Cacti can be in graphing what’s going on in your server environment. Even if you don’t have alerting, simply graphing what your “normal” usage is can alert you to problems as well as help you put timelines together that allow you to figure out the source.
I was glancing over some server utilization charts and saw this one, which shows CPU usage jumped way off the charts over Christmas break:
Why is that? We didn’t suddenly quintuple in size? Digging closer, I realized a definite pattern to the CPU load:
You can see that the load quiets down at night, and goes up in the morning, in pretty much a specific pattern. Digging into the graphs revealed that it was almost down to the minute, which probably means it’s some type of automated source, as no user works from 7:00 a.m. to 10:30 p.m. every day.
The network graph showed a similar pattern, which gave me a good shot of capturing it. I turned on Network Monitor, and ran a capture for 30 seconds, here’s what it saw:
Holy cow! In 30 seconds I saw over 30,000 Frames from some of those clients! The highest “normal” client I see is 136 frames in that time period. Now that I knew where the traffic was coming from, I just had to figure out why. I contact the administrator for those clients, who said that they had been re-imaged in the last few weeks.
Further investigation has shown these clients to have all been imaged with an improperly prepared image, causing them to essentially fight over the same records in Active Directory and DNS continuously. The quiet periods were when the computer labs were shut down for the evening automatically to save energy, and then automatically powered back up in the morning before classes started in them.
