Who Cares if the Rebreather Has Integrated Deco
For some time now, Innerspace Systems has been working on a Megalodon head called APECS 3 that supports integrated decompression. As with any major software / hardware engineering project, there have been some delays, which has Meg owners clambering for information about when it will come out. It’s amazing how so many of these rebreather divers are pestering the company and acting like a bunch of kids a few days before Christmas. What I don’t really understand is why people are so anxious.
It’s not that I wouldn’t like to have integrated deco, but I really don’t see it as being all that big a deal. When software gets more complex it also gets more buggy, which is why I’m pretty happy having a very basic loop controller. Keeping the deco on a different unit like a VR3 is a nice modular system, and besides, I don’t really even use the computer on really deep dives.
When I plan a bigger dive, I do it like this:
- Work out the details on the laptop
- Cut the tables and laminate them (wrist mounted slate)
- Cut bailout tables and laminate them (also on wrist)
- Fill 02 and Diluent
- Fill bailout using thirds
- Do the dive as it was planned and as it appears on my wrist.
While I use the computer to validate my deco schedule, it is really only there for backup.
Again, it would be nice to have integrated deco, but IMHO, you should not do big dives if you can’t maintain a setpoint. Provided you can, or even if you depend on your loop controller to do it, your actual setpoint will match that on your computer. Everything should jive and you can validate the deco schedule on your wrist.
It’s tempting just to jump in, do a gnarly dive and depend on your computer to get you out of it, but doing so ignores some of the basic safety precautions of technical diving like proper gas management, which is a risk that I really don’t feel comfortable taking.
RHEL3 Upgrade to RHEL4 Breaks up2date
Last week I had to upgrade one of our old RHEL3 servers in order to get it to address disks larger than 2TB. I did the upgrade from CD, and it went fairly smoothly, except up2date would not run after the box came back up.
It gave me the following error:
[root@x up2date]# Traceback (most recent call last):
File "/usr/sbin/up2date", line 27, in ?
from up2date_client import repoDirector
File "/usr/share/rhn/up2date_client/repoDirector.py", line 5, in ?
import rhnChannel
File "/usr/share/rhn/up2date_client/rhnChannel.py", line 10, in ?
import up2dateAuth
File "/usr/share/rhn/up2date_client/up2dateAuth.py", line 5, in ?
import rpcServer
File "/usr/share/rhn/up2date_client/rpcServer.py", line 23, in ?
from rhn import rpclib
ImportError: No module named rhnIt turns out that there is no “really easy” way to fix it, but these directions on spaceblog do work. Basically it involves removing a lot of packages and re-adding them. The problem is related to python, so rather than remove the entire list of packages, I focused only on those relating to python and up2date:
libxml2-python
popt
pyOpenSSL
python
rhnlib
rhpl
up2date
Make sure not to remove these packages:
rpm
rpm-libs
rpm-python
Or you will break rpm and not be able to add the packages back after you remove them. All told, this is a grisly process, and you will have to use rpm -e --nodeps in order to get it done. This sucks, but up2date will work everything out once you can get it running again.
How to Make Gnarly Big Linux Filesystems
At least in RHEL 4, the fdisk command does not support the creation of filesystems larger than 2TB. In order to get around it, you have to use the parted command. I found the basic info here, but this is the long and short of how to cut off a big ol’ slice of disk using parted:
Run parted
# /sbin/parted
It’s interactive, so the following commands are issued within the utility.
1) Make the disk label
(parted) mklabel gpt
2) Create the partition
(parted) mkpart primary 0 -1
3) Verify
(parted) print
Disk geometry for /dev/sda: 0.000-38146.972 megabytes
Disk label type: msdos
Minor Start End Type Filesystem Flags
1 0.031 101.975 primary ext3 boot
2 101.975 38146.530 primary lvm
4) Exit the GNU Parted command shell
(parted) quit
5) Finally, make the filesystem:
# mkfs.ext3 -m0 -F /dev/sdb1
6)Finally, you don’t want to wait for that big filesystem to fsck from time to time, so make sure it does not get checked unless you run the command yourself:
# tune2fs -c0 -i0 /dev/sdb1
That should just about do it. Remember that only RHEL 4 and higher can support filesystems larger than 2TB. If I remember correctly RHEL 3 can go up to 2TB, RHEL4 can handle 8TB, and RHEL 5 can make a whopping 16TB chunk of disk. Have fun!
I Can Finally Have My Rocket Belt!
Juan Manuel is my new hero, plain and simple! Since the Bell RocketBelt of the early 1960’s, the world has been disappointingly devoid of this amazing invention, but no longer. Juan Manuel, a self-taught engineer from Mexico has been working diligently for nearly 30 years to develop a working rocket belt and now he has.
Supposedly the biggest trick to making these rigs work is getting the throttle to operate smoothly enough, but there are a number of other challenges as well. They run on 90% pure hydrogen peroxide which is extremely caustic, so material compatibility is a huge factor. You can’t just march into your nearest drug store and pick up this highly concentrated chemical either, so there are also many issues surrounding the distillation process of the fuel.
Lozano’s commitment to his projects is truly impressive. He has financed everything himself, and come up with a product that seems to work every bit as well as the old Bel Rocket Belt, but looks even cooler! What’s more, I can have one of these Jet Packs on sale now for $125,000! That may seem like a lot of money, but it is really very reasonable when you consider what you get:
1. A fully-tested, custom-made flying rocket belt,
2. This belt has been proved to be the most stable design and easier to fly
3. A special machine to make our own unlimited supply of rocket fuel
4. Hands-on training in the process and the equipment
5. Flight training of 10 flights in your own rocket belt
6. Maintenance and setup training
7. 24/7 expert support
8. Housing and food are included during training
When you think that the original rocket belt cost Bell Aerosystems $250,000 dollars in 1960, and that the guys from “The Rocket Belt Caper” spent a great deal more, you can only conclude that $125,000 is very reasonable indeed. This is not to say I can run out and buy one, but I admit that I am tempted by thoughts of being a full-time professional jet pack pilot.
Well done Lozano! My hat goes off to you!
