Of Cattle and Pets
And Bessie the friendly cow, and that ratty cat you never really liked.
I have been thinking a lot about cattle and pets lately (in the IT sense). If you are not aware of the concept, it's something that Randy Bias (from EMC/Cloudscaling) coined and the admins at CERN made popular. It basically says, you can treat your servers like pets or like cattle.
It's a great simple way to think . . .
Linked Out
Recently we have been fighting with a nasty problem. It started around new years, and had gradually been getting worse.
We use Mellanox 6036 switches for our cloud. They're Infiniband switches, but we run most of the ports in ethernet mode, since you can do that if you have the license. That part is actually pretty cool.
. . .A HPC admin in a Cloud world
Disclaimer: Personal experience may alter your perception of reality. This also applies to yours truly.
This post is also somewhat generalized, there are tons of approaches for HPC and IaaS.
I have a background in administering High Performance Computing (HPC) systems. As I have a lot of colleagues working with HPC, and IaaS . . .
Volumes of trouble
Disclaimer Juno + CentOS7 (and CentOS6 for the cinder-volume host). Currently this service serves LVM backed cinder volumes over iSCSI.
So, a few days ago we had our customers contacting us. They seemed to have problems with cinder volumes. Some new volumes just didn't attach to VMs. They went to "attaching" and then . . .
The Devil, Juno
A long upgrade
It's hard to find enough relevant Magic the Gathering card names for the blog post. It's much easier to come up with puns. And they're almost as awesome. So here we are.
Anyway, to the point. We're not on Icehouse anymore. Yay.
OpenStack upgrade Icehouse -> Juno
We recently updated our OpenStack . . .
Frantic Search
Keystone v3 API and admin token
Basic disclaimer. Still CentOS 6 + Icehouse (hope that's the last time I'll write that).
The problem
The OpenStack Python APIs are a bit, uhm, optimistically documented. As in "I'm sure people will figure it out". Well that's why I'm writing this.
I tried to get the keystone v3 API . . .
Fate Transfer
Migrating from CentOS 6 to CentOS 7
We have run OpenStack for a while, and always on CentOS 6. It's old and virtualization-wise somewhat restricted. Currently we're on OpenStack Icehouse. The Juno packages don't exist for CentOS 6 so we need to make the challenging jump to CentOS 7 before upgrading.
This is mainly a problem for the compute nodes. The . . .
Posted in: centos6migrationsopenstack
