Archive for the ‘ Fedora Linux ’ Category
This is my first time checking in on the blog in 4ish years, but I’m thinking of picking things back up. I’m still heavily using Open Source GIS at work, primarily QGIS and PostGIS. I’ve managed to set PostGIS up on a Raspberry Pi running Fedora so I might write up a quick how-to on that. In addition at work we fly UAVs collecting data to create orthophotos, DEMs, and point clouds, we do indoor scanning and use ground penetrating radar to map sub-surface features.
Here’s the easiest way to get a very up-to-date installation of PostGIS up and running quickly. First up, set up the Postgres 9.5 repository straight from Postgres:
sudo rpm -ivh https://download.postgresql.org/pub/repos/yum/9.5/fedora/fedora-24-x86_64/pgdg-fedora95-9.5-3.noarch.rpm
Next up, install Postgres:
sudo dnf install postgresql95 postgresql95-server postgresql95-libs postgresql95-contrib postgresql95-devel
The -devel package is optional, but I will be building Ruby’s PG gem later so it needs to be there for me. If you have no such plans feel free to skip it. If you want a GUI to help manage the database add the ‘pgadmin3’ package to the list. Now it is time to initialize the database. Do so with:
sudo /usr/pgsql-9.5/bin/postgresql95-setup initdb
That will take a minute to run as it sets up the initial database. Once the database is initialized start Postgres with systemd by running:
sudo systemctl start postgresql-9.5
If you want Postgres to start at boot run the same command but change ‘start’ to ‘enable’ before you reboot or shutdown. Next up is a little housekeeping. Set a password for the Postgres account. I like to do this in the database itself rather than on the Postgres user account. To do so run:
sudo -i postgres psql postgres
This starts a psql session as the Postgres user then in psql allowing you to set the password with:
\password postgres
Next up since this is just a development box I’ll change Postgres’ login method from Ident to MD5.
sudo gvim /var/lib/pgsql/9.5/data/pg_hba.conf
Change all ‘peer’ and ‘ident’ to ‘md5’. If this is a production server you’ll want a more secure and robust login method. However, if you don’t want bother with passwords at all instead of ‘md5’ replace them ‘trust’. Next up is installing PostGIS. It and nearly all its dependencies are nicely packaged in the Postgres repository making it easy to keep the two in sync. Install PostGIS with:
dnf install postgis2_95 postgis2_95-client
As a test you can create a database called ‘test’ and enable PostGIS with:
sudo -u postgres createdb test
psql -d test -U postgres -W -c "CREATE SCHEMA postgis; CREATE EXTENSION postgis WITH SCHEMA postgis; ALTER DATABASE test SET search_path TO public, postgis;"
psql -d test -U postgres -W -c "SELECT postgis_full_version();"
If the last command returns information about the version of PostGIS installed you’re good to go. Have fun!
So far I’ve only noticed a few superficial differences between Fedora and Arch. One of the cooler Fedora features is Presto. Where Arch uses Pacman to as its package management system Fedora uses Yum. Presto is an add-on to the Yum system that allows users to download only the changes to installed binaries. For example today a new version of Libreoffice hit the Fedora repositories. Where under Arch I would have had to download 99MB of files, but thanks to Presto only sending the changes I downloaded a total of 3 MB. This is a great feature for those on slower connections or who are under monthly bandwidth caps.
A few months back my old Dell Inspiron laptop died. It was a warhorse, surviving drops onto concrete floors, being stepped on by a big dog. The cap to the zero key popped off, and the tab key would stick from time to time but it kept on trucking. Most of the bezel around the monitor had broken / fallen off, I think this was the downfall. Finally the monitor quit working. I couldn’t work with it docked up to an external monitor so I replaced it with an ASUS K55N.
If I were a Windows only user it would be a great laptop for the price, but due to work and personal preference I’m booted into Linux 99% of the time. This suited me well on the Dell, its 2GB of RAM and aging processor made Windows molasses slow, meanwhile the Linux side hummed right along as long as I didn’t have too many browser tabs full of Flash videos open at once. However, on the ASUS I kept running into issue after issue.
First of all getting Arch onto the ASUS was a chore. Part of the problem was this was my first attempt at installing an OS onto a UEFI machine. Eventually after figuring out how to turn off the secure boot feature I was able to boot to the Arch LiveCD installer. The installation went fine until I tried to reboot and GRUB2 did not take over. For some reason the efimanager did not install or run correctly during the installation process. Eventually I switched to ReFind and figured out how to manually add an entry for it in the laptop’s boot order.
Once Arch was installed I had a few more problems to work through. Suspend wouldn’t work, I gave up on solving that issue and switched to using Hibernate instead. Another issue was with the sound system, I could not get audio to work for more than one program at a time, and once a program “claimed” the sound no other program could output to the speakers until the first program was closed. Going through pages of Google results pointed to PulseAudio as the culprit, but I could not remedy the situation. Both of these were minor annoyances, the final straw moving me from Arch to Fedora was QGIS stopped working.
The first two problems were most likely hardware related. QGIS however was an Arch only issue. The problem came about as a result of the Achilles heel of rolling release distributions, a key library was updated to a version incompatible with QGIS. I was unable to launch QGIS and compiling a new version would fail. Facing a deadline I decided to wipe Arch and move on to Fedora.
Installing Fedora was much easier than installing Arch. Partly due to the fact I was now more familiar with the ins and outs of UEFI, but also Fedora’s installer is a user friendly GUI and Arch’s installer is a wiki page on their website.
Fedora has generally run better on the ASUS. The audio system now works perfectly, but I can no longer hibernate. The laptop will hibernate, but on recovery the screen goes black. The computer is running, switching to a different TTY allows me to log in and run commands from the command line, but I can’t get the screen to come back on. I think this is due to the ATI video card and its radeon driver. Hopefully I can find a solution soon.
I was able to get my GIS stack installed, all of the programs I use are in Fedora’s repository. I did have to make a change to GDAL, I use several non-open GIS data formats (ESRI File Geodatabases, MrSID rasters, and ERDAS ecw rasters). Under Arch it was just a matter of downloading the appropriate API or SDK, altering the default PKGBUILD file to point to the appropriate libraries and recompiling. Under Fedora you have to edit the SPEC file, and SPEC files are much more complicated that Arch’s PKGBUILD files. In addition Fedora’s package management system expects any libraries that a packaged program is complied against to be accounted for in a package. Eventually I got it all sorted out and I got back to work.
I’m still too new to Fedora to do a comparison between it and Arch. Certainly installing Fedora is much easier than installing Arch. For day to day use they are about the same, in fact since I kept my /home on a separate partition they are nearly identical experiences. Both use systemd to manage services, and both give you up to date software. That was one worry about moving to Fedora, Arch’s rolling release always gave me easy access to the latest versions of the software I used on a daily basis. Although Fedora isn’t rolling release all of the software I use is the latest and greatest. QGIS, PostGIS, Postgres, LibreOffice, etc are all up to date. As I said earlier the rub comes when I need to tweak software from the Fedora default. Perhaps it will get easier for me as time goes on, or perhaps I’ll flush my root directory and reinstall Arch.
Boring Nerdy Stuff 