Friday, October 29, 2010

RedHat Cloud Offerings

My organization has server clusters that host about 100 VMs and more are coming. These systems were built using RedHat's cluster manager and Xen or KVM virtualization. Do we have what some would call a private cloud? Not yet, but we're considering getting closer. Since we're already using RedHat we're looking into what they recommend first.

According to a RedHat sponsored IDC paper: "Cloud services are shared, standardized service and are available from a self-service catalog; able to scale in an 'elsatic' fashion as needed; [can be] priced on actual usage; accessible via the Internet; and supportive of published APIs".

The above definition makes me believe we're on our way to having a private cloud and RedHat's cloud offerings include everything we've done above with a few additions which would allow our clusters to satisfy the cloud definition. The additions are specifically what RedHat calls cloud management services and RedHat implements them with the following three packages.

  • Satellite, which provides configuration management and network services via DHCP, DNS, and PXE. Since we use RHN and have a kickstart server this doesn't seem like too much of a reach for us. I can also imagine Satellite offering the functionality I experienced when I tried out EC2. We're going to look more into satellite, spacewalk, and possibly puppet.
  • RHEV-M, which offers a GUI for managing VMs similar to vmWare's virtual infrastructure client or EC2's VM manager. It implements the catalog aspect of the cloud definition and allows for easy deployment. Our current method of deploying VMs is to virt-clone a golden image and our catalog consists of Ubuntu Server, Fedora 13, Win200{3,8} (yuck), and RHEL5.5. We then console into the cloned system, update it's network configuration (our clusters have several networks trunked into them) and other settings. Does RHEV-M make this easier? RHEV-M also offers live migration, high availability, load balancing, and power saving, though we have all of this from vanilla clusvcadm and just haven't yet implemented power saving or ballooned dynamic memory. We're comfortable doing this via the CLI and are considering scripting it, though we're still considering trying RHEV-M to make sure we're not missing out.
  • MRG Grid, which implements the API aspect defined above for portability between clouds. This feature allows one to automatically spin a VM out to EC2 as per a certification between RedHat and Amazon. We have do not yet have this feature and move VMs using tricks like dd|nc, mounting snapshots and doing virt-clones, etc. I wonder how quickly and what with service interruption a VM can be moved to another cloud and back.

Monday, October 25, 2010

evercookie

Beware the evercookie.

Wednesday, October 20, 2010

Disable Evoluent vertical mouse thumb and bottom buttons

My Evoluent vertical mouse has a thumb and bottom button. I got the mouse for ergonomic reasons, not for these buttons, and I occasionally click them by accident which causes actions I didn't intend. The following xmodmap command disables them:
xmodmap -e "pointer = 1 2 3 4 5 15 14 13 12 10 11 9 8 7 6"

Sunday, October 10, 2010

bash set theory

Intersection of two files:
$ cat one
a
b
c
$ cat two
b
c
d
e
$ for x in `cat one`; do grep $x two; done
b
c
$
Complement of two files:
$ cat one
a
b
c
$ cat two
b
c
d
e
$ sort one one two | uniq -u
d
e
$ sort two two one | uniq -u
a
$ 
After playing around for a little I found Peteris Krumins' blog who provided the complement method I'm pasting above.