It seems that the maintainer of the wireshark package in Fedora has updated to version 1.8.1 in the current Fedora Rawhide, which will become Fedora 18. The schedule tells us that Fedora 18 is planned to be released on 2012-11-06 (the latest schedule m…
I am an avid cobbler+puppet user. This allows me to rely on my cobbler server and puppet manifests to describe how servers/workstations are setup. I only backup my configs and data, and I regenerate failed machines PRN. I’ll be publishing … Continue reading →
Many thanks to johnmark in #gluster for syndicating my “gluster” tagged blog posts on http://www.gluster.org/blog/ I aim to keep these posts technical and informative, aimed mostly at other sysadmins and gluster users. Please don’t be shy to comment on my … Continue reading →
Daniel Abadi described his blog entry about Hadoop connectors as a “Stonebraker-style rant” and then delivered on the threat. Like everything Stonebraker has written in the last five years, it’s based on a fundamentally flawed premise, which is that HDFS stores unstructured data. This assumption is not clearly stated, but it’s pretty clear from context, […]
When I first read about reduce side joins in hadoop, I spent some time walking through a bunch of examples from this whitepaper by Jairam Chandar on Hadoop join-algorithms.In the beggining, everything seemed simple enough – because I was focusing on jo…
Using RAW Devices In VirtualBox VMs
Usually, VirtualBox creates its virtual machines in disk images
(.vdi, .vmdk, etc.). This tutorial explains how you can use RAW devices
from the host (partitions, LVM volumes, etc.) and create a VirtualBox VM
in …
I’ve been having some strange networking issues with gluster. “Eco__” from #gluster suggested I try an up to date Intel nic driver. Here are the steps I followed to make that happen. No news yet on if that solved the … Continue reading →
For the last ~two or so years I’ve played and tested gluster on and off and hanging out in the awesome #gluster channel on Freenode. In case you haven’t heard, gluster was acquired by RedHat back in October 2011. This post … Continue reading →
With the addition of automated self-heal in GlusterFS 3.3, a new hidden directory structure was added to each brick: “.glusterfs”. This complicates split-brain resolution as you now not only have to remove the “bad” file from the brick, but it’s counte…
The new hi1.4xlarge instances in EC2 are pretty exciting, not only because they’re equipped with SSDs but because they’re also equipped with 10GbE and placement groups allow you to create server clusters that are closely colocated with full bandwidth among them. I was about ready to do another round of GlusterFS testing to see the […]
OpenVZ: Mounting Host Devices/Partitions/Directories In A Container With Bind Mounts (Debian/Ubuntu)
Sometimes you are in a situation where you need to mount a hard
drive, partiiton or directory from the OpenVZ host inside an OpenVZ
container – fo…
Ring-based consistent hashing is one of my favorite algorithms. It’s an elegant solution to a common set of problems, and many times I’ve seen people’s eyes light up when they realize that finding data among a set of servers doesn’t have to involve central directories or expensive lookups. Systems based on this capability are still […]
Striping Across Four Storage Nodes With GlusterFS 3.2.x On Ubuntu 12.04
This tutorial shows how to do data striping (segmentation of
logically sequential data, such as a single file, so that segments can
be assigned to multiple physical devices in a…
A while ago, I wrote about my High Speed Replication translator, comparing it to the existing method of replication. Bottom line: my version was about 50% faster for small synchronous random writes at the time. Well, times have changed. Here’s part of the commit message for my latest update to HSR. This version works with […]
Node Install
So lets begin by installing the a node. The node install is pretty standard but there are a few very important steps that have to be done or it wont work correctly. All the issues I have found have been put into bugzilla. Before you begi…
Gluster Volume Setup
Now that all the nodes are setup and added to the cluster we need to tweak a few settings create our 1st volume and add it to the data center. Before completing these steps please make sure you have gone though and confirm you hav…
Functional languages replace the need for mutability by providing us with convenient, idiomatic mechanisms for defining transformations without explicitly modifying or assigning variables. This level of decoupling transparently provides us with n…
Distributed Storage Across Four Storage Nodes With GlusterFS 3.2.x On Ubuntu 12.04
This tutorial shows how to combine four single storage servers
(running Ubuntu 12.04) to one large storage server (distributed storage)
with GlusterFS.
The client sy…
As people who attended my recent Red Hat Summit talk are aware, one of the big issues with GlusterFS replication is “split brain” which occurs when conflicting updates are made to replicas of a file. Self-healing in the wrong direction risks data loss, so we won’t do self-heal if we detect split brain and we’ll […]
Starting with GlusterFS 3.3, one change has been the check to see if a directory (or any of it’s ancestors) is already part of a volume. This is causing many support questions in #gluster.
This was implemented because if you remove a brick from a volum…