[ale] Small Clusters for VMs

Derek Atkins derek at ihtfp.com
Fri Oct 28 22:53:47 EDT 2016


Jim,

On Fri, October 28, 2016 10:37 pm, Jim Kinney wrote:
> On Oct 28, 2016 10:28 PM, "Derek Atkins" <warlord at mit.edu> wrote:
>>
>> So here's a question:  have you tried running oVirt on a single machine
>> (sort of like the old vmware-server)?  I.e., a single machine that has
>> CPU and Disk, running a hypervisor, ovirt-engine, etc?
>
> Closest is the converged setup with the manager as a vm.

I presume you mean the "Hosted Engine" configuration?

>>
>> It seems silly to run NFS off a local disk just to get Self-Hosted oVirt
>> to work..  But of course they stopped supporting the "AllInOne" in
>> ovirt-4.0 and don't seem to support local storage for the
>> SelfHostedEngine.
>
> Can't do local storage for converged. Just use the host system to provide
> the storage.

I.e., run an NFS server on the host that exports the local file system? 
That really sounds like a reduction in performance, especially since I
have SSDs.

>> Any Ideas?
>>
>> Second question:  is there a web-ui password-change for the AAA-JDBC
>> plugin?  I.e., can users change their own passwords?
>
> Not that I've seen. Adding users to the internal auth process is not
> recommended. Ldap is recommended. I use freeipa.

I suppose I could run freeipa in another vm (or even on the host).  I
already run a kerberos domain, but I dont want to have to rekey
everything, and AFAIk there is no way to transfer the data from an
existing kerberos domain to freeipa.  That seems so heavyweight..
especially for only 3-6 users.

But
https://www.ovirt.org/develop/release-management/features/infra/aaa-jdbc/
seems to imply I can store user data in the database....

>> -derek

-derek

>>
>> Jim Kinney <jim.kinney at gmail.com> writes:
>>
>> > On Fri, 2016-10-28 at 10:49 -0400, DJ-Pfulio wrote:
>> >
>> >     Thanks for responding.
>> >
>> >     Sheepdog is the storage backend. This is the way cloud stuff works
> on
>> >     the cheap. Not a NAS.  It is distributed storage with a minimal
>> >     redundancy set (I'm planning 3 copies).  Sheepdog only works with
> qemu
>> >     according to research, which is fine.
>> >
>> >     Sure, I could setup a separate storage NAS (I'd use AoE for this),
> but
>> >     that isn't needed. I already have multiple NFS servers, but don't
> use
>> >     them for hosting VMs today. They are used for data volumes, not
> redundancy.
>> >
>> >            >> Opinions follow (danger if you love what I don't) <<
>> >
>> >     Won't be using oVirt (really RHEL only and seems to be 50+
>> different
>> >     F/LOSS projects in 500 different languages [I exaggerate] ) or
> XenServer
>> >     (bad taste after running it 4 yrs).  I've never regretted
>> switching
> from
>> >     ESX/ESXi and Xen to KVM, not once.
>> >
>> > Ovirt is only 49 projects and 127 languages! Really!
>> >
>> > Ovirt is just the web gui front end (pile of java) with a mostly
>> python
>> > backend that runs KVM and some custom daemons to keep track of what is
> running
>> > and where. It is most certainly geared towards RHEL/CentOS. That may
>> be
> an
>> > irritant to some. I've found the tool chain to JustWork(tm). I need
>> VMs
> to run
>> > with minimal effort on my part as I have no time to fight the
> complexity. I've
>> > hacked scripts to do coolness with KVM but found Ovirt did more than I
> could
>> > code up with the time I have. It really is a GPL replacement for
>> VMWARE
>> > Vsphere.
>> >
>> >     And won't be dedicating the entire machines just to being storage
> or VM
>> >     hosts, so proxmox clusters aren't an option.  The migration from
> plain
>> >     VMs into sheepdog appears pretty straight forward (at least on
> youtube).
>> >
>> > One thing I like with Ovirt is I can install the host node code on a
> full
>> > CentOS install or use the hypervisor version and dedicate a node
> entirely.
>> > I've used both and found them to be well suited for keeping VMs
> running. If
>> > there is an issue with a node, I have a full toolchain to work with. I
> don't
>> > use the hypervisor in production.
>> >
>> > A major issue for my use is the need to have certain VM up and running
> at all
>> > times. Ovirt provides a process to migrate a VM to an alternate host
>> if
> it
>> > (host or VM) goes down. The only "gotcha" of that is the migration
> hosts must
>> > provide the same cpu capabilities so no mixing of AMD and Intel
>> without
>> > setting the VMs to be i686.
>> >
>> >     Just doing research today. Need to sleep on it. Probably won't try
>> >     anything until Sunday night.
>> >
>> > Download CentOS 7.2
>> > Install VM host version
>> > yum install epel-release
>> > Follow direction here: https://www.ovirt.org/release/4.0.4/
>> > starting with:
>> > yum install
>> http://resources.ovirt.org/pub/yum-repo/ovirt-release40.rpm
>> >
>> > Be aware that when docs refer to NFS mounts, the server for that can
>> be
> one of
>> > the nodes that has drive space. ISO space is where <duh> iso images
>> are
> kept
>> > for installations. I have one win10 VM running now for a DBA with
> specialty
>> > tool needs.
>> >
>> >     On 10/28/2016 10:23 AM, Beddingfield, Allen wrote:
>> >
>> >         Will you have shared storage available (shared LUN or high
> performance NFS for the virtual hard drives that all hosts can access?)
>> >         If so, the easiest free out of the box setup is XenServer or
> oVirt.  I'm familiar with XenServer, but there are some oVirt fans on
> here,
> I know.
>> >
>> >         --
>> >         Allen Beddingfield
>> >         Systems Engineer
>> >         Office of Information Technology
>> >         The University of Alabama
>> >         Office 205-348-2251
>> >         allen at ua.edu
>> >
>> >         On 10/28/16, 9:17 AM, "ale-bounces at ale.org on behalf of
> DJ-Pfulio" <ale-bounces at ale.org on behalf of DJPfulio at jdpfu.com> wrote:
>> >
>> >             I'm a little behind the times.  Looking to run a small
> cluster of VM
>> >             hosts, just 2-5 physical nodes.
>> >
>> >             Reading implies it is pretty easy with 2-5 nodes using a
> mix of
>> >             sheepdog, corosync and pacemaker running on qemu-kvm VM
> hosts.
>> >
>> >             Is that true?  Any advice from people who've done this
> already?
>> >
>> >             So, is this where you'd start for small home/biz redundant
> VM cluster?
>> >
>> >             I've never done clustering on Linux, just Unix with those
> expensive
>> >             commercial tools and that was many years ago.
>> >
>> >             In related news - Fry's has a Core i3-6100 CPU for $88
> today with their
>> >             emailed codes.  That CPU is almost 2x faster than a first
> gen Core
>> >             i5-750 desktop CPU. Clustering for data redundancy at home
> really is
>> >             possible with just 2 desktop systems these days. This can
> be used with
>> >             or without RAID (any sort).
>> >
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>> >
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>>
>> --
>>        Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
>>        Member, MIT Student Information Processing Board  (SIPB)
>>        URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
>>        warlord at MIT.EDU                        PGP key available
>


-- 
       Derek Atkins                 617-623-3745
       derek at ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant



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