Enabling webGL with Fedora 16

In Fedora 16, detection of WebGL fails for some reason (I haven’t looked into this too throughly).

What worked for me was to visit (in Google Chrome):

chrome://flags

I then enabled “Override software rendering list” and clicked the restart button at the bottom left.

WebGL worked without a hitch (i’m using a Sapphire ATI 6850 graphics card if it matters).

Increasing the size of a LUKS cryptfs partition

Warning: This guide assumes that the partition you’re expanding into is adjacent to a pool of free space. Things get a bit trickier if that isn’t the case (re-arranging your partitions is probably necessary).

The system that I performed this on: Fedora 16 KDE install, on a 120GB SSD installation (migrated from an 80GB SSD using Acronis True Image). Fedora doesn’t set encryption up via LVM in the installer, seemingly opting for a plain vanilla container.

Step 0: Boot into a live CD environment. I used a Fedora 16 KDE respin CD which had all these tools. Open a console (in KDE this was `konsole`).

Step 1: Blow away the partition itself. You’ll need to do this with `fdisk`. Make a new partition, with the cluster of free space included. Select Linux for type when prompted (usually 82 OR 83). Write changes to disk.

Step 2: Open your crypted filesystem:

# Replace /dev/sda2 with your own filesystem

# cryptsetup luksOpen /dev/sda2 root 

Step 3: Expand the crypted FS

# cryptsetup resize root

# e2fsck -f /dev/mapper/root

# resize2fs -p /dev/mapper/root

Step 4: Safety hat

# cryptsetup luksClose root

# sync; sync; reboot

Including one package in a yum repository

Yum can be surprisingly simple and frustrating at once. To add only one package from a repository you can do the following.

In the yum configuration file for the repository (normally this is /etc/yum.repos.d/$repository.repo).

[rpm_repository_something]
includepkgs=vlc

You can also glob to include all packages of that type, such as:

includepkgs=vlc*

Save the file, and search/install new packages. Yum will only see packages of “vlc” and nothing else.

If you are looking to do the opposite, the keyword is `exclude`. To exclude all rpms from a repository for instance:

exclude=*

Don’t add both exclude and includepkgs together without careful consideration.

opsview and notifications

To send a notification to an external party in opsview (3.13.1) there are a few things to do:

1. Attach keywords in the host configuration to that particular host (unique no, spaces, special characters, underscores are okay).
2. Setup a new role (with the NOTIFYSOME permission, which is vaguely documented) + check off the ‘all’ box in the keywords permission section.
3. Add a contact with an e-mail address.
4. Add a notification profile attached to that e-mail address, with specific keywords to notify on checked off.
5. In the keywords section, click to flag all services with the specified keyword (otherwise no notifications will appear).

For the lazies (which means pretty much every systems administrator out there) there is, (thankfully) a *full* REST API with JSON built into opsview (unlike some of the other Nagios derivatives). More on that later hopefully.