I was bored during the holidays and decided to brush up on my python skills. I have created a small python program to list the topology of a Gluster volume, called lsgvt (LiSt Gluster Volume Topology). It’s at github. To give you a small example of it’s output:
The only correct way to disable IPv6 on RHEL6…is to leave it on. That is, most people in the blogophere suggest disabling one or two modules using a file in /etc/modprobe.d. This is not the correct way. These modules must stay running. The correct way is to add a config line to the following two config files:
Fedora 17 has a GRUB2 version that supports booting from a boot partition in a LVM logical volume. That means you can have a full LVM layout of your disk(s) without a separate physical partition for /boot. I want that! Now, I’m rather pleased with my current Fedora setup, so I did not want to do a full re-install. What to do? Would it be possible to lite:rary “move” my existing partitions into LV’s, including /boot? Turn’s out this can be done and it’s fairly (..) easy. You need to have at least the same amount of free disk space available as the separate partitions combined , either in an existing Volume Group or in unused disk space.
Just a quick post how to create a minimal install (cli only) with Fedora 17.
- First, don’t use the live CD, but either the “Install DVD” or the “network install CD”, both of which you can find here.
- Next, when you boot up with one of these install media (either physical or virtual) you are presented with a minimalist GRUB menu. Press TAB within the default boot timeout value of 60s.
- You get presented the grub linux start command. Append the line with the parameter “text” and press <enter>
- You will be brought into a text mode install with much less options. Go through the setup questions as you normally would. When using the network installation CD you will also be asked to configure the NIC, because it is an over-the-network install. Just fill in for your local situation to get to the Net. You need DNS. You can use Googles DNS is you don’t know any: IP = 18.104.22.168
There are quite a lot of resources on RedHat products these days. Great learning materials! RedHat has made most of it’s resources available through its customer portal on http://access.redhat.com. Some of the content is only available if you have a RedHat login. If you don’t have one you can easily register yourself by making a corporate or personal account here.
Just a quick tip: If you don’t use MS Visio, for whatever reason, but you need to make a great looking network infrastructure drawing, here is a great looking icon set for just that purpose. You can download both svg and png formats.both png’s and svg’s have transparent backgrounds which is great for constructing compositions. Only the svg’s are scalable. For MS Office you can only use the png set. For wiki’s and Libre Office you can use both. The icon set is based on the also free Tango icon library, often used in Gnome desktop environments. The set is licensed according to Creative Commons Share-alike.
It proves to be very poorly documented how to exactly have a VMware Linux guest update the size of a scsi device to reflect the increase of the virtual scsi disk (vmdk) online. The magic command is:
RHEL6 has a nice new feature: LVM snapshot merging. This basically means that you can merge a snapshot back into it’s origin LV. RHEL installations normally have their OS installed on LVM (If you don’t, please reconsider. You don’t know what your missing).