Yes this is the point of hyperconverged. You only need three hosts to setup a proper hci cluster. I would recommend ssds for gluster storage. You could get away with non raid to save money since you can do replica three with gluster meaning your data is fully replicated across all three hosts.


On Tue, Jun 23, 2020 at 5:17 PM David White via Users <users@ovirt.org> wrote:
Thanks.
I've only been considering SSD drives for storage, as that is what I currently have in the cloud.

I think I've seen some things in the documents about oVirt and gluster hyperconverged.
Is it possible to run oVirt and Gluster together on the same hardware? So 3 physical hosts would run CentOS or something, and I would install oVirt Node + Gluster onto the same base host OS? If so, then I could probably make that fit into my budget.


Sent with ProtonMail Secure Email.

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Monday, June 22, 2020 1:02 PM, Strahil Nikolov via Users <users@ovirt.org> wrote:

> Hey David,
>

> keep in mind that you need some big NICs.
> I started my oVirt lab with 1 Gbit NIC and later added 4 dual-port 1 Gbit NICs and I had to create multiple gluster volumes and multiple storage domains.
> Yet, windows VMs cannot use software raid for boot devices, thus it's a pain in the @$$.
> I think that optimal is to have several 10Gbit NICs (at least 1 for gluster and 1 for oVirt live migration).
> Also, NVMEs can be used as lvm cache for spinning disks.
>

> Best Regards,
> Strahil Nikolov
>

> На 22 юни 2020 г. 18:50:01 GMT+03:00, David White dmwhite823@protonmail.com написа:
>

> > > For migration between hosts you need a shared storage. SAN, Gluster,
> > > CEPH, NFS, iSCSI are among the ones already supported (CEPH is a little
> > > bit experimental).
> >

> > Sounds like I'll be using NFS or Gluster after all.
> > Thank you.
> >

> > > The engine is just a management layer. KVM/qemu has that option a
> > > long time ago, yet it's some manual work to do it.
> > > Yeah, this environment that I'm building is expected to grow over time
> > > (although that growth could go slowly), so I'm trying to architect
> > > things properly now to make future growth easier to deal with. I'm also
> > > trying to balance availability concerns with budget constraints
> > > starting out.
> >

> > Given that NFS would also be a single point of failure, I'll probably
> > go with Gluster, as long as I can fit the storage requirements into the
> > overall budget.
> > Sent with ProtonMail Secure Email.
> > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > On Monday, June 22, 2020 6:31 AM, Strahil Nikolov via Users
> > users@ovirt.org wrote:
> >

> > > На 22 юни 2020 г. 11:06:16 GMT+03:00, David White via
> > > Usersusers@ovirt.org написа:
> >

> > > > Thank you and Strahil for your responses.
> > > > They were both very helpful.
> >

> > > > > I think a hosted engine installation VM wants 16GB RAM configured
> > > > > though I've built older versions with 8GB RAM.
> > > > > For modern VMs CentOS8 x86_64 recommends at least 2GB for a host.
> > > > > CentOS7 was OK with 1, CentOS6 maybe 512K.
> > > > > The tendency is always increasing with updated OS versions.
> >

> > > > Ok, so to clarify my question a little bit, I'm trying to figure
> > > > out
> > >

> > > > how much RAM I would need to reserve for the host OS (or oVirt
> > > > Node).
> > >

> > > > I do recall that CentOS / RHEL 8 wants a minimum of 2GB, so perhaps
> > > > that would suffice?
> > > > And then as you noted, I would need to plan to give the engine
> > > > 16GB.
> >

> > > I run my engine on 4Gb or RAM, but i have no more than 20 VMs, the
> > > larger the setup - the more ram for the engine is needed.
> >

> > > > > My minimum ovirt systems were mostly 48GB 16core, but most are
> > > > > now
> > >

> > > > > 128GB 24core or more.
> >

> > > > But this is the total amount of physical RAM in your systems,
> > > > correct?
> > >

> > > > Not the amount that you've reserved for your host OS?I've spec'd
> > > > out
> > >

> > > > some hardware, and am probably looking at purchasing two PowerEdge
> > > > R820's to start, each with 64GB RAM and 32 cores.
> >

> > > > > While ovirt can do what you would like it to do concerning a
> > > > > single
> > >

> > > > > user interface, but with what you listed,
> > > > > you're probably better off with just plain KVM/qemu and using
> > > > > virt-manager for the interface.
> >

> > > > Can you migrate VMs from 1 host to another with virt-manager, and
> > > > can
> > >

> > > > you take snapshots?
> > > > If those two features aren't supported by virt-manager, then that
> > > > would
> > >

> > > > almost certainly be a deal breaker.
> >

> > > The engine is just a management layer. KVM/qemu has that option a
> > > long time ago, yet it's some manual work to do it.
> >

> > > > Come to think of it, if I decided to use local storage on each of
> > > > the
> > >

> > > > physical hosts, would I be able to migrate VMs? 
> > > > Or do I have to use a Gluster or NFS store for that?
> >

> > > For migration between hosts you need a shared storage. SAN, Gluster,
> > > CEPH, NFS, iSCSI are among the ones already supported (CEPH is a little
> > > bit experimental).
> >

> > > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > > > On Sunday, June 21, 2020 5:58 PM, Edward Berger edwberger@gmail.com
> > > > wrote:
> >

> > > > > While ovirt can do what you would like it to do concerning a
> > > > > single
> > >

> > > > > user interface, but with what you listed,
> > > > > you're probably better off with just plain KVM/qemu and using
> > > > > virt-manager for the interface.
> >

> > > > > Those memory/cpu requirements you listed are really tiny and I
> > > > > wouldn't recommend even trying ovirt on such challenged systems.
> > > > > I would specify at least 3 hosts for a gluster hyperconverged
> > > > > system,
> > >

> > > > > and a spare available that can take over if one of the hosts
> > > > > dies.
> > >

> > > >

> >

> > > > > I think a hosted engine installation VM wants 16GB RAM configured
> > > > > though I've built older versions with 8GB RAM.
> > > > > For modern VMs CentOS8 x86_64 recommends at least 2GB for a host.
> > > > > CentOS7 was OK with 1, CentOS6 maybe 512K.
> > > > > The tendency is always increasing with updated OS versions.
> >

> > > > > My minimum ovirt systems were mostly 48GB 16core, but most are
> > > > > now
> > >

> > > > > 128GB 24core or more.
> >

> > > > > ovirt node ng is a prepackaged installer for an oVirt
> > > > > hypervisor/gluster host, with its cockpit interface you can
> > > > > create and
> > >

> > > > > install the hosted-engine VM for the user and admin web
> > > > > interface.  Its
> > >

> > > > > very good on enterprise server hardware with lots of RAM,CPU, and
> > > > > DISKS.
> >

> > > > > On Sun, Jun 21, 2020 at 4:34 PM David White via Users
> > > > > users@ovirt.org wrote:
> >

> > > > > > I'm reading through all of the documentation at
> > > > > > https://ovirt.org/documentation/, and am a bit overwhelmed with
> > > > > > all of
> > >

> > > > > > the different options for installing oVirt.
> >

> > > > > >

> >

> > > >

> >

> > > > > > My particular use case is that I'm looking for a way to manage
> > > > > > VMs
> > >

> > > > > > on multiple physical servers from 1 interface, and be able to
> > > > > > deploy
> > >

> > > > > > new VMs (or delete VMs) as necessary. Ideally, it would be
> > > > > > great if I
> > >

> > > > > > could move a VM from 1 host to a different host as well,
> > > > > > particularly
> > >

> > > > > > in the event that 1 host becomes degraded (bad HDD, bad
> > > > > > processor,
> > >

> > > > > > etc...)
> >

> > > > > >

> >

> > > >

> >

> > > > > > I'm trying to figure out what the difference is between an
> > > > > > oVirt
> > >

> > > > > > Node and the oVirt Engine, and how the engine differs from the
> > > > > > Manager.
> > >

> > > > >

> >

> > > > > >

> >

> > > >

> >

> > > > > > I get the feeling that `Engine` = `Manager`. Same thing. I
> > > > > > further
> > >

> > > > > > think I understand the Engine to be essentially synonymous with
> > > > > > a
> > >

> > > > > > vCenter VM for ESXi hosts. Is this correct?
> >

> > > > > >

> >

> > > >

> >

> > > > > > If so, then what's the difference between the `self-hosted` vs
> > > > > > the
> > >

> > > > > > `stand-alone` engines?
> >

> > > > > >

> >

> > > >

> >

> > > > > > oVirt Engine requirements look to be a minimum of 4GB RAM and
> > > > > > 2CPUs.
> >

> > > > > > oVirt Nodes, on the other hand, require only 2GB RAM.
> > > > > > Is this a requirement just for the physical host, or is that
> > > > > > how
> > >

> > > > > > much RAM that each oVirt node process requires? In other words,
> > > > > > if I
> > >

> > > > > > have a physical host with 12GB of physical RAM, will I only be
> > > > > > able to
> > >

> > > > > > allocate 10GB of that to guest VMs? How much of that should I
> > > > > > dedicated
> > >

> > > > > > to the oVirt node processes?
> >

> > > > > >

> >

> > > >

> >

> > > > > > Can you install the oVirt Engine as a VM onto an existing oVirt
> > > > > > Node? And then connect that same node to the Engine, once the
> > > > > > Engine is
> > >

> > > > > > installed?
> >

> > > > > >

> >

> > > >

> >

> > > > > > Reading through the documentation, it also sounds like oVirt
> > > > > > Engine
> > >

> > > > > > and oVirt Node require different versions of RHEL or CentOS.
> >

> > > > > > I read that the Engine for oVirt 4.4.0 requires RHEL (or
> > > > > > CentOS)
> > >

> > > > > > 8.2, whereas each Node requires 7.x (although I'll plan to just
> > > > > > use the
> > >

> > > > > > oVirt Node ISO).
> >

> > > > > >

> >

> > > >

> >

> > > > > > I'm also wondering about storage.
> > > > > > I don't really like the idea of using local storage, but a
> > > > > > single
> > >

> > > > > > NFS server would also be a single point of failure, and Gluster
> > > > > > would
> > >

> > > > > > be too expensive to deploy, so at this point, I'm leaning
> > > > > > towards using
> > >

> > > > > > local storage.
> >

> > > > > >

> >

> > > >

> >

> > > > > > Any advice or clarity would be greatly appreciated.
> >

> > > > > > Thanks,
> > > > > > David
> >

> > > > > > Sent with ProtonMail Secure Email.
> >

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> >

> > >

> >

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