Restricting access to a .ssh key for a specific command
Posted by Christian Stone
at 06:44 PM EST in category General
The following example shows how to restrict a public key in the authorized_keys (.ssh directory) file to only run the specified command, along with other restrictions on the connection. The limitations must be listed on one line, prior to the lengthy public key data.
command="rsync --server -v --timeout=999 --delete-excluded . backup/client",↵
no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty ssh-rsa AAAAB3Nza…
Bosch 4000-09 10" Worksite Table Saw
Posted by Christian Stone
at 12:00 AM EDT in category General
I just ordered my new tablesaw! It is a Bosch 4000-09 10" Worksite Table Saw with Gravity-Rise Wheeled Stand. I hope that this one will surpass my old one in the quality and accuracy because I'd love to build some nicer pieces of furniture! After I put it to use, I'll let you know how well it works!
Handling moles in the yard...
Posted by Christian Stone
at 01:12 PM EST in category General
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I'm starting to have trouble with moles in the yard. And I spent a lot of time searching the Web for information about getting rid of them. The consensus is that nothing works well, but traps are better than poisons or smoke bombs. However, I also learned that Glenn R. Dudderar, Extension Wildlife Specialist at Michigan State University found that applying a diluted solution of castor oil "effectively eliminated the visible surface tunneling of eastern moles" at 26 of 27 test sites. I've tried it and it seemed to work well for me. While there are directions on the packages of 'Scoot Mole' and 'Mole Med' to follow, I also found a recipe in a newspaper. This formula uses substantially less castor oil than called for on the package, but as I said, it seemed to work for me. I'm going to do it again this spring. The formula and instructions are - [quote] Ingredients: - 8 oz. of castor oil
- 3 oz of Ivory dish soap
- 7 oz of water
From this concentrated solution, add water at a ratio of two ounces of concentrate to one gallon of water. This means that your 18 ounces of concentrate will make nine gallons of mole deterrent, which will cover 5,000 square feet. Instructions: You are urged to spray the perimeter of your property rather than the whole yard. A 4 to 6 foot band around your lawn will keep new families of moles away for six years. [note: I think this was supposed to say six MONTHS.] You must "water in" the castor oil to get it into the soil. Don't apply this solution when there is a threat of heavy rains, as the oil may wash away with the excess water runoff. Don't be alarmed if the moles cross the barrier after you apply the solution. It takes time and water to get the oil to penetrate the soil to a depth where the moles tunnel. [/quote]
Installing drivers for a Highpoint RocketRaid card in Fedora.
Posted by Christian Stone
at 01:14 PM EDT in category General
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Installing a Highpoint RocketRaid 1820A and Fedora Core 3 kernel 681 on i386 Single Processor System. I have successfully built drivers for the Highpoint RocketRaid 1820A for Fedora Core 3 on i386 Single Processor System.
However, while finding doumentation online was the key to building the
driver, I thought I'd share the process with you in as much detail as I
can in hopes that this will be useful to other people. If you would like my copy of the driver, just email me! If
you want to follow these directions, first install the card on your
system and configure your disk array on bootup. Boot into linux
and (as root): Step 1: DOWNLOAD THE KERNEL SOURCE FOR YOUR KERNEL VERSION.a. Download kernel source RPM from http://download.fedora.redhat.com/pub/fedora/linux/core/updates/3/SRPMS/. For the latest kernel that I have, the source file was kernel-2.6.9-1.681_FC3.src.rpm. b. Install your new kernel: # rpm -i kernel-2.6.9-1.681_FC3.src.rpm -vvc. Prepare the kernel source code with Red Hat modifications # cd /usr/src/redhat/SPECS# rpmbuild -bp --target=i686 kernel-2.6.specd. cd to kernel tree located in /usr/src/redhat/BUILD/.
Verify you are in there by looking at your directory and noting a
configs directory. In resulting tree, the configurations for the
specific kernels shipped in Fedora Core 3 are in the /configs/
directory. For example, the i686 SMP configuration file is named
/configs/kernel-<version>-i686.config. The multi-processor
machine source has SMP appended to the filename. Issue the following command to place the desired configuration file in the proper place for building: # cp <desired-file> ./.config
e. Now build the source objects. Yes, this is necessary... # make oldconfig# makeCongratulations! You are one step closer to hard drive Nirvana! a. Download the openbuild driver from http://www.highpoint-tech.com. The appropriate driver I downloaded: rr182x-openbuild-v1.11.tgz. While you are there, download the HighPoint Raid Management Software. Expand the files with # tar -zxvf rr182x-openbuild-v1.11.tgz
b.
You now need to build the driver against the source directory you just
worked on. Issue the command from within the directory of your
driver source. On Fedora Core 3, this is: # make KERNELDIR=/usr/src/redhat/BUILD/kernel-2.6.9/linux-2.6.9a. Not quite done! In order to install it, you need to upgrade your module-init-tools (you can get them from http://www.kernel.org/pub/linux/kernel/people/rusty/modules/). Download the module-init-tools-3.0.tar.gz.
NOTE: 3.1 module-init-tools will not work. Follow the included
instructions after exploding the archive using the command:
# tar -zxvf module-init-tools-3.0.tar.gz
b. Now that you've installed the module-init-tools, you need to update your local databases:
# depmod
b.
This driver relies on other modules that you have to make certain are
loaded first. So (this is from the README from the highpoint
source) first load module "scsi_mod" and "sd_mod" if they are not built
into kernel:
# modprobe sd_mod
c. Load your new driver. For kernel 2.6 (Fedora core 2 and 3), the driver module is "hptmv.ko".
# insmod ./hptmv.ko
d.
If you haven't, download the HighPoint Raid Management software. Run
server, run client, log in and test! If your system plays nicely,
you should see your happy new card and drivers.
Step 4: LOADING AND MOUNTING YOUR RAID DISKSa.
Your system is likely different then mine, but I have simply one large
array on the card, and linux is NOT installed on my raid array at
boot. Please modify your instructions accordingly, and look
elsewhere if you want to install linux on your raid array. These
install instructions will not help you.
With that in
mind, you need to first partition the disk. I chose 1
partition. With only one mounted array, you can simply partition
it with:
# fdisk /dev/sda
b. Now you can format your partition(s). They will be mounted (if your drive was sda) as sda1 for the first, sda2 for the second. You can choose any format you like, I chose the new journaling linux format.
# mkfs -t ext3 /dev/sda1
c.
Finally, you need to mount the disk on your system. There are two
steps, the first is creating a mountpoint, which is just a folder that
will map to the drive. It can be most anywhere, the most common
places are either at the root level of your system such as /raid or as
in the /mnt directory such as /mnt/raid. The folder name doesn't
matter, as long as it doesn't conflict with other resources already
installed on your system. The second task is telling your linux
box to mount the new disk at that point.
# mkdir /mnt/raid
# mount -t ext3 /dev/sda1 /mnt/raid
Step 5: CONFIGURING TO LOAD DRIVERS AND MOUNT UPON BOOTNow go ahead and try to access the new disk at that directory! You should have no problems. You are also almost done. The problem is that your mounting of the disk, as well as the installation of the drivers themselves was only temporary.
The only thing that will remain is the directory you created as a
mountpoint. If you want them to load at the same mountpoint on
boot, continue with the following directions.
a. Configure
system to load and mount the new drive. You need to first copy
the driver to a common place where it will look at boot. Make certain
you adjust the path for your kernel build version. cd to your compiled driver directory and do that:
# cp hptmv.ko /lib/modules/2.6.9-1.681_FC3/kernel/drivers/scsi
b. Now you need to instruct the system to load the driver on boot. Edit /etc/rc.sysinit and
install the following lines of code right after the SCSI module
loads. I will display a few lines from rc.sysinit as well as my
code, with the additions in bold.
# SCSI
for module in `/sbin/modprobe -c | awk '/^alias[[:space:]]+scsi_hostadapter[[:space:]]/ { print $3 }'` $scsi; do
load_module $module
done
load_module floppy
# Add in Highpoint Raid Card
/sbin/insmod /lib/modules/2.6.9-1.681_FC3/kernel/drivers/scsi/hptmv.ko
c.
Save your changes and reboot. You can cross your fingers,
sacrifice a chicken, or anything that will bring you luck, but you
shouldn't need it! You are done!
I hope this was
helpful! If so, drop me a note of thanks. If there are
errors here, point them out to me and I will adjust the instructions.
Doctor Who
Posted by Christian Stone
at 12:53 AM EDT in category General
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Yes they are in fact producing new episodes of Doctor Who! The first episode is called Rose and may not make it to the US, but I hope someone picks it up!
Lord of the Rings Symphony
Posted by Christian Stone
at 01:17 PM EST in category General
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When I heard that the amazing work behind the music of the Lord of the Rings
trilogy has grown into a full orchestral concert, and that it was
selling out all over the world, I had to jump on the bandwagon! Before
I could put down my burning visa card, I had ordered two tickets to the
performance in the Meyerhoff Symphony Hall in downtown Baltimore. After having fully experienced the concert, I have to admit, I was a bit let down. The music was, actually, excellent. Johan De Meij
did a great job in his composition, and on that merit alone I would say
the symphony was worth it. There was also a companion video, done in
earthy tones and hilighting the story from the epic movie, that played
along with the concert, and that was also well done. So what was the
problem? The two elements together, at least in my opinion, left the
listener submerged in an onslaught of visual and audio images that
together distracted them from the whole. The orchestral concert tried
too hard to be both an orchestral piece AND an epic movie in short. The
end result was that I was less then satisfied as the visual told too
little of the story to be truly satisfying, and the symphony itself
showed a weakness in appeasing the visual needs of the presentation,
leaving what should be some recurring themes throughout the synphony as
a one hit wonder, and other tunes that played constantly throughout the
epic trilogy should only have been played in the beginning, and perhaps
the end of the symphony. At the end of the performance, I didn't
feel like I quite listened to what the symphony should have become, and
was saddened, because I felt that the musical themes from the movie
were strong enough to actually be pulled together into a symphony on
their own merits without having to tie themselves so close to the plot
and timeline of the movie. The result was an orchestral concert for the
massess, with so much paid in the lifeblood of the symphony to appease
the listeners that very little is left to truly enjoy over time. If you are interested, you can buy the orchestral CD here.
Upgrading your TiVo
Posted by Christian Stone
at 01:38 AM EST in category General
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For those of you who are seeking to upgrade your TiVo, and are
seeking information as to how to perform such a task, the internet is
ripe with information. What is harder to find but just as useful is the
answer to the question of what can go wrong, and perhaps, what more
could be added to what you have read online. My first warning is not to increase your TiVo storage by adding another hard drive without first backing up and them expanding your archive on the new hard drive with the -s 127
option. This will expand the amount of swap space on your new larger
hard drive. Do not do what I did and just throw in another hard drive,
blessing it. Why? Well, if you do not, the most likely possibility is
that your TiVo will start crashing more and more over time, as it
cannot handle processing the larger capacity of your hard drives in the
memory of your TiVo, and without the swap space as backup, bad things
happen. With this first bit of learning, I set my feet on the
path of a true, powerful upgrade... adding networking capability,
repairing the crashing, and speeding up the aging device. Part 2, network card etc. After some careful research, I set out to buy the TiVo CacheCard
from 9th Tee Enterprises. I also had to buy some RAM, in my case, 512
MB for just under $100. Yep, in a few years someone will read this and
laugh at how expensive it was, but believe me that in todays market it
was a pretty damn good deal! I then properly removed the hard drives,
backed the data up on a linux machine, installed the cachecard drivers
from the site, as well as the TivoFlash utility (in my case from an
older build, because the most recent drivers caused a failure in the
drive), and placed the new drives carefully back in the TiVo unit.
After some careful working in the tight space, I reassembled the case
and plugged it all back in! Green Screen of Death Yes,
that what came next. A most unhappy me seeing the "GSOD". However,
after some thought it occured to me that TiVo wouldn't come up with
such a thing unless it was surprisingly common, so I went back online,
and the "GSOD" only apparently means that there were some file
corruption issues that TiVo was repairing, and that things should be
back to normal within 15 mins to 24 hours. Sure enough, when I returned
downstairs to check on my TiVo again, it was playing TV like nothing
had happened! Playing with the new installation The
first thing I did was the ",#401" prefix to test the TiVo dial up over
the network. And it worked! No more POTS for the TiVo! Yes, I do plan
on switching my POTS to an internet phone, and TiVo was my last
holdout. Now no more baby bells! The second was to telnet into the box
and "peek around". Again, no problem. And the navigational speed of my
TiVo is "zippy", or another way of saying it was that it is not the
happy side of fast! So what did I install on my TiVo? First, I installed the tivo-bin.tar.gz files in /var/hack/bin.
That gave me all the linux commands I needed with the possible
exception of a good text editor... yes you have to ftp for now! Second,
I followed the advice of this site for downloading your TiVo programming to your mac to burn to DVD from this web page.
Now, if there ever is a crash again, I can determine the cause from the
logs, edit my TiVo online, and overall have a very enjoyable time with
it. If you have any questions in your own upgrade, feel free to email
me. Glad to help!
Color Electronic Paper
Posted by Christian Stone
at 01:40 AM EDT in category General
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A fantastic announcement today that will possibly lead to a revolution in print is from Hitachi. Apparently, in as early as 2006 we will have color electronic paper commercially available! Yes, just imagine a single sheet of paper, eventually flexible, with the same resolution and clarity of regular paper, and not needing a backlight to view. An interesting news release detailing the invention of black and white electronic paper is from New Scientist. Some of the things I look forward to are: - Picture frames that you can change the art or image in them with an inserted media disk, and then removing the electric charge, and the image will remain for months, or years.
- No more wasted paper on news media
- No longer a heavy burden dragging a stack of books with you everywhere you go.
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