I'm new to openstack and i'm still learning. In 2 month i'll get 6 servers like:

  • 4 servers with dual xeon e5-2630 , 96gb ram, 2 1gb ethernet and 2 500gb hdd in raid
  • 1 DAS with 40tb of storage (10x4tb HDD)
  • 1 server with single xeon e5-2630 with 16-32 gb of ram.

I has a few questions for this setup and with openstack in general:

  • i practically has 3 dedicated compute nodes, 1 compute+storage node(1 server+DAS) and 1 node/network controller. As i read the best practice for networking server is to have this service run on all nodes for redundancy as opposed to running on a single controller where is it fails then all the ecosystem fails too.What is your oppinion? Another thing is the colocation of services as i don't have the necessary number of hardware to deploy every service on it's private hardware. I was thinking that the controller should run the controlling part service of nova, the object storage server and block storage server and the compute+storage server should run nova+object storage+block storage. What do you think of this setup?

  • for the DAS should i use raid or not because i read somewhere that swift and opesntack in general doesn't get along very well with raid?

  • should i use openstack-networking or the newer quantum?
  • i'll use this servers for hosting, storage like dropbox and virtualization. Except the latter, the first 2 will run in VMs . The thing is that i don't understand how openstack works with available resources. Does it make a pool of the available ram, cpu, storage etc? The DAS will be connected to only 1 server. Reading and writing to disk uses ram memory for cache etc;my question is : will openstack fill the ram proportionaly on all nodes when reading or writing or will it use only the ram from where DAS is attached to?This is an important problem for me. Also, only having one machine with actual storage capability will it help adding 2 more 1gb ethernet to cope with intense requests on the storage server? Or should i distribute the HDD's to all servers and install the storage services on them?
  • i didn't find a good tutorial on how to deploy openstack using maas and juju, because it seems to be an easier setup then manual install.
  • how does openstack get along with amd opteron 6300 series? I'm asking this because there is a possibility that i could change from intel to amd, the latter being much cheaper so i can get for the same ammount of money twice and something the number of cores (e5-2630 being a 6 core with ht, and from what i understand i should disable ht)

    To be continued when i will be confronted by other problems.

Thank you for your help!

  • So no support? Problem is we have dropped to 4 servers and a DAS. What are my options? I think swift is out of the picture now!
    – Capsali
    Aug 5 '13 at 12:01
  • I don't know much about openstack, but does this help? OpenStack-Grizzly-Install-Guide, and Deploying OpenStack.
    – Mitch
    Aug 10 '13 at 13:48
  • Note that this question may be better suited for Server Fault or the official Q&A site for Openstack.
    – Kupiakos
    Aug 20 '13 at 22:57
  • One thing I noticed - you state "1 DAS with 40tb of storage (10x4gb HDD)". Do you mean "1 DAS with 40gb of storage (10x4gb HDD)" or "1 DAS with 40tb of storage (10x4tb HDD)"? I assume the latter.
    – Kupiakos
    Aug 22 '13 at 13:43



Having networking services running on every node will have its advantages and disadvantages.

Many different networking redundancy possibilities are possible including multi-hosting.

Multi-Hosting requires adding an IP on the VM network to each host in the system, and you'll probably get a slight performance decrease on the compute host.

It's also possible to combine this with a hardware gateway to remove the need for your compute hosts to gateway, and they'd only need to DHCP and NAT for VMs.

Another noted disadvantage of Multi-Hosting is the additional uses of IP's in a subnet.

Take a look at this document for more info.

In my opinion, it's probably a good idea to multi-host.


The Openstack documentation recommends you do not use RAID, the reason being that Swift is very write-heavy and performs very poorly with most parity-based RAID (e.g. RAID 5 or the more complicated RAID 26).

Don't forget to backup your data, of course!

Openstack-Networking vs. Quantum/Neutron

Distribution of Resources

I really can't help as much as I would want here. I'd give this article a read, and ping the IRC Channel.

Installing with MAAS and Juju

Ubuntu provides a tutorial for Ubuntu Cloud Infrastructure installation with MAAS and Juju.

CPU: Intel vs. AMD

I cannot find any good information whether AMD or Intel is better for Openstack. Based on the absence of information on the subject, I would think there's very little disadvantage. The Openstack Documentation refers to both AMD and Intel chips in a similar fashion.

The page only states that AMD-V is required, and the Opteron 6300 specifications page states it does.

On the topic of hyper-threading, it will double the logical cores, and that may be good. It's recommended you stress-test both configurations to see which is faster.

More Help

Ask Ubuntu may not have been the best location to ask these kinds of questions.

Try these places if you have questions or want a professional opinion:

  • thank you for clearing some things up or me! I'll try asking in openstack q&a also. The problem is that beeing a new to this whole thing i don't understand how the services work with each other and if there are conflicts if colocating them. As i understand there are 2 types of storage in openstack : block storage (cinder) and object storage (swift) . Cinder is used for providing the vm's with persistent storage and swift is exactly what is sais it is. But can i use swift to provide volumes for vm's? Thank you for your help and i'll try getting more answer's from openstack and serverfault!
    – Capsali
    Aug 23 '13 at 14:35
  • No problem. However, realize that the proper etiquette for bounties is to mark an answer as correct before the deadline. Half of the bounty was withheld and is gone.
    – Kupiakos
    Aug 23 '13 at 15:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.