Getting those pesky “Warning: The resulting partition is not properly aligned for best performance” messages when creating partitions on your new 3TB-4TB disk using GNU parted under Linux?
Start parted with the “-a optimal” command line parameter to tell parted to use optimal alignment!
/sbin/parted -a optimal /dev/sdd
Thanks go to this post on Ask Ubuntu!
I upgraded our server to Fedora 16 from Fedora 14 recently, so I thought I’d continue my tradition of posting the solutions to the problems I encountered to help others.
Two major changes in Fedora recently increased the difficulty of this upgrade: the switch to grub2 from the grub legacy bootloader, and the switch to systemd from Upstart and SysV-style init.
I used the PreUpgrade method once again to reduce downtime and avoid burning a disc.
References to read first:
- How to use PreUpgrade
- Common Fedora 16 bugs
The new Vantage Pro2 Plus weather station worked, recording about one inch of precipitation during the recent rainfall! Now I just need to get the USB interface working and wview set up to analyze the results.
We installed the weather station up on the roof along with the new Wineguard HS-1000 omnidirectional HD antenna, which is also working well. Dropped cable over a year ago – Netflix + other streaming + broadcast is good enough and costs a lot less!
I hope to combine the data from the weather station (including the UV and solar radiation sensors) and the TED 5000 whole-house energy monitor to correlate temperature and other weather changes with energy usage and solar PV power generation from the solar arrays also on the roof.
Update: Success! The weather station is online (after much fighting with hardware and interfaces)! Check out Wumple Weather and station KTXAUSTI146 on the WeatherUnderground.
Here’s a problem I ran into recently: I temporarily switched the root filesystem of my Fedora 14 install from RAID-5 to non-RAID. After I received the new SSD drives, I switched it to RAID-1 but the dracut boot sequence could not find the RAID-1 array and mount the root filesystem, ending in the errors ‘Can’t mount root filesystem. Boot has failed, sleeping forever’.
Using the dracut rdshell and rdinitdebug kernel boot options to get a shell prompt from the dracut initramfs led me to the RAID assembly failing during boot during “dracut: Autoassembling MD Raid”. I discovered manually assembling the array using mdadm –assemble … then exiting the shell would allow the boot to continue, so at least I had a temporary workaround.
To fix the dracut auto assembly of the RAID array, I did the following:
- Booted up a Fedora Live CD so I could manipulate the RAID partitions without them being mounted/used (since they contained the root filesystem).
- After noticing that the volume type was wrong on one of the RAID-1 member partitions by running blkid (TYPE was not “linux_raid_member”) and making sure the other partition was up-to-date with the data, I used wipefs (remember to use the -a option) on the partition with the incorrect data (and let the next step sync the data from the correct partition).
- Set the system hostname via the hostname command, then did “mdadm –assemble /dev/md1 /dev/sda2 /dev/sdb2 –update=name –update=uuid”. This fixed the array name to be hostname:1.
- After booting the system back up normally with the workaround, made a backup of /etc/mdadm.conf then did “mdadm –examine –scan > /etc/mdadm.conf” and made sure /etc/mdadm.conf looked correct afterward.
After these steps, the dracut boot sequence was able to auto-assemble the RAID array on boot and mount the root filesystem.
I hope this writeup helps someone who runs into a similar problem.
Have a USB-attached CyberPower System UPS but can’t get it to work with Network UPS Tools aka nut 2.6.0 (such as from the Fedora 14 or 15 rpms)? See the link to the rpms below I built.
The errors you might see (especially when running usbhid-ups -D -D -D) include “could not connect to ups”, “libusb_get_report: error sending control message: Operation not permitted”, and “Can’t retrieve Report 03: Operation not permitted”.
There is a workaround for a libusb issue affecting communication with USB CyberPower Systen UPSs in the trunk branch of the nut source code that will get into nut 2.7, but was not part of nut 2.6. See the fix here in change 2893 on nut’s trac system. Read more about the problem in this message on nut-upsuser.
To get the fix now (before the 2.7 rpms are released), I rebuilt nut 2.6 rpms (with small changes to the spec file) using the latest source snapshot from nut’s buildbot, r2978. You can download these r2978 rpm’s from here.
Have a Neato XV-11 robotic vacuum cleaner with an intriguing USB port?
Check out Hash’s post at the Random Workshop about connecting to the XV-11′s built-in serial subsystem via USB to send and receive commands and data from the vacuum. I’m using a Linux box and minicom. :-)
Now I just need a miniature embedded Linux platform with wifi so I can wirelessly communicate with the robot while it vacuums so I can try to create images from the LIDAR data as it maps the house…
I upgraded Fedora 12 to Fedora 14 over the weekend using PreUpgrade for the first time. (I tried a direct yum distro-sync upgrade first but it got stuck in infinite dependency loops.)
Overall I was impressed with the download size reduction and the install speed after rebooting the system for the anaconda installer to apply the new packages. I liked the reduction in system downtime resulting from downloading all the packages before the reboot and the smaller set of packages that were installed.
Some extra steps I had to deal with:
- There are a couple bugs in the version of PreUpgrade that is part of Fedora 12. This post on The Wily Blog contains the fixes to the preupgrade-cli script needed for it to run.
- preupgrade-cli needed /etc/sysconfig/i18n to exist but it was missing on my system. I created the file with the default values from the Fedora docs to get past this issue.
It also seemed like the install asked a few redundant questions it could have figured out before the reboot to start the install:
- The installer asked whether to do a fresh install or an upgrade, where a PreUpgrade is obviously an upgrade.
- The installer asked which filesystem’s installation to upgrade (there was only one on the system), and then again asked which filesystem to add to the “upgrade” list. I believe it could have assumed the same filesystem for both questions, and even possibly set default values for all of them based on the filesystems in use when PreUpgrade was run before the reboot.
- The installer asked which interface provided the internet connection for downloading additional packages and images, which PreUpgrade could have figured out before the reboot and passed it along.
This upgrade was the most painless Fedora or Red Hat upgrade I’ve done in years! Almost all of my services worked afterward with no reconfiguration. A big thanks and hats off the the Fedora team for PreUpgrade!
At the Chevy Volt test drive, waiting in line…
Inhabit posted a story about a net-zero energy small house (1,051 sq ft) built recently in Fort Worth:
Zero Energy Casita in Texas Opens to the Public | Inhabitat – Green Design Will Save the World.
Lisa and I recently went on the Austin Cool House Tour co-sponsored by the Texas Solar Energy Society and Austin Energy Green Building.
We realized the efficiency retrofits to our home were pretty similar to what we saw on the tour, so for fun I thought I’d write up the green feature list of our house in the same format as used by the tour book.
Spangler Home – Northwest Austin
Built as a traditional non-green building, this Austin home has been retrofitted for energy efficiency and simple but high-tech living.
Owners: Lisa and Jason Spangler
Solar PV: Texas Solar Power Company
- 10KW grid-tied solar photovoltaic array
- Whole-home energy monitor (TED 5000).
- White reflective metal roof (Sheffield Metals CoolR Solar White Galvalume – Reflectivity 0.68, Emissivity 0.85, SRI 82, 25% recycled content, 100% recyclable – installed by Southwest Metal Roofing Systems).
- Level 2 EVSE (electric vehicle car charger) and a Chevy Volt range-extended electric car
- Lawn replaced with native plant and prairie garden which requires almost no supplemental watering. Crushed granite and limestone paths allow water penetration. Mature trees provide shade.
- R-38 insulation in attic with R-8 ductwork. R-9 garage door insulation.
- 1 gpm low-flow showerheads (from New Braunfels-based Bricor). Shut-off values on showers for optional Navy shower.
- Solar screens on all windows.
- Energy Star appliances from the highest CEE efficiency tier (dishwasher, refrigerator, clothes washer and dryer). Energy Star electronics.
- 19 SEER multi-zoned HVAC system with variable speed motor and fan coils, and programmable thermostats.
- All lighting is CFL or LED. (LED fishtank and main kitchen lighting reduces energy usage of most-used lights.)
- High efficiency aerodynamic ceiling fans with timed remotes throughout. (Gossamer Wind fans)
- Masonry and fiber cement siding and trim (Hardiboard).
- Ethernet networking (Cat6) and high speed Internet connection enables telecommuting to save energy and reduce emissions. Energy-efficient computers. Notebook and Home theater systems that sleep when not in use.
- Weather station (Davis Vantage Pro2 Plus)
- Easy access to transportation – bike lanes, public transportation (bus stop 0.4 miles away), two light rail stations nearby (4.0 and 5.2 miles).
Any other ideas for increasing energy efficiency or going more green? Leave the in the comments!
Update: Here is an aerial photo of the metal roof and solar panels from Google Maps: