I agree with Nataraj about kvm/qemu/libvirt, we have 10+ hypervisors running it and it meets our needs but none of them are particularly heavily loaded. The only caution I would give is that there are occasions (mainly in the snapshot-associated arena) where the man page may simply say "do this" but, when you run the command on a distribution focusing on longer term support, you find it's not yet supported. And there are areas where Red Hat flatly states that there are issues (snapshots of the operating environment rather that just disk images). While this is true (for example, reverting to a snapshot reverts causes the system to have the date/time of the revert as well), we have still found value in these kinds of snapshots in a development environment.

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________________________________________ From: CentOS centos-bounces@centos.org on behalf of Gregory P. Ennis PoMec@PoMec.Net Sent: Sunday, July 1, 2018 9:53 PM To: CentOS mailing list Subject: [EXTERNAL] Re: [CentOS] Centos 7.5 on Vmware

On 06/28/2018 02:03 PM, Gregory P. Ennis wrote:

Everyone,

I am in the initial study phase of putting together a larger virtual server while using Centos 7.5 as the operating system of choice for the individual virtual machines.

How do you all like VMware for this, or what other software allows for the development of virtural servers that use Centos 7.5

Thanks ahead of time for giving me a head start with your experiences!!!!

It would be helpful if you gave more details about what you were looking for? Are you planning to run a bare metal hypervisor, or vmware under Linux or windows? What are you performance requirements? IO? CPU? What will the VM's be used for? Do guests requre a graphics console?

Various vmware products ranging from ESXI to vmware workstation are very popular. I've run several of them. They work. I now use the Linux included, kvm/qemu based Red Hat/CentOS virtualization and it meets my needs very well for general testing/development, email server, web server kind of stuff. I also use this setup along with spice to run test systems with various graphic GUI's. I would not say that my virt servers are very heavily loaded. I have a Dell R210 running CentOS6 KVM/Qemu and a Dell XPS 9360 running Ubuntu 18.04 with kvm/qemu.

If you prefer fancy mangement GUI's over writing scripts and editing config files, vmware might be better for you. kvm/qemu does include virt-manager which is a fairly simply GUI to create and manage VM's, but the user interface is not as comprehensive as the interface for managing ESXi.

Red Hat does have their high end virtualization products, of which I believe at least 1 is a bare metal hypervisor. I have no personal experience with those products, though if client came to me with need, I would examine and seriously consider the Redhat products.

One advantage to the kvm/qemu solution or possibly the redhat virtualization product is more integrated support. When I ran vmware, I used to run into situations where I wanted to beta test the newest release of some random linux distribution only to find out that vmware had not yet implemented support for the graphics driver or some other new hardware feature being used in the OS that I was trying to test. In this way, kvm/qemu feels more integrated. Like other software, kvm/qemu has bugs here and there, but overall, I'm very happy with it and I like the price of using it under CentOS and Ubuntu.

I see clients all the time, go out and spend a fortune on huge vmware clusters, that end up very lightly loaded and could easily be run on a simple kvm/qemu server running under CentOS (or even one of the desktop virtualization solutions) with a backup server for redundancy, so I suggest to consider what your requirements really are. You could always go with Redhat if you require support.

Nataraj

--------------------------------------------------------- Nataraj,

Thank you very much for your comments. I have not put together a virtual machine at this point, so my tree structure of logic is still very weak.

However, I have three Centos 7.5 machines and one Centos 5.10 that could reasonably function together.

Actually the plan has been to upgrade the Centos 5.10 which is a database server to Centos 7.5. Currently this is on a SuperMicro SCSI and we planned to purchase a new machine with SATA drives because 7.5 does not install on SCSI drives. While planning for this change we thought of looking a virtual systems on one larger unit.

The other units that are already running 7.5 are a mail/archive server, a gateway that controls all of the traffic in and out of the network, and a backup server. These units service about 30 users, and all machines have heavy use :) (ok at least by my standards).

Thank you again for your recommendations!!!!!

Greg _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos

On 29/06/18 07:03, Gregory P. Ennis wrote:

Everyone,

I am in the initial study phase of putting together a larger virtual server while using Centos 7.5 as the operating system of choice for the  individual virtual machines.

How do you all like VMware for this, or what other software allows for the development of virtural servers that use Centos 7.5

Thanks ahead of time for giving me a head start with your experiences!!!!

We're using KVM/Qemu on CentOS 7.

We changed away from VMware after a lot of trouble with poorly supported infiniband drivers (particularly for RDMA and especially SRP with multipathing to OpenIndiana based ZFS backend storage). Infiniband support on CentOS is mature and actively supported upstream. In comparison with VMware where we were left to manually install drivers available from OFED (a complete pain to do with every upgrade and left us with regular 'Purple Screens of Death').

KVM/Qemu + libvirt also gave us the ability to do live migrations without having to buy into a higher level of support on VMware.

On the stack we run Windows Servers/Clients, Linux Servers (CentOS 5,6,7; Arch; Ubunutu). Virt-Manager allows reasonable graphical tools for management but there's so much you can do with scripting through virsh and generally with other OS tools (bash, python, etc.).

I've recently dabbled with an old piece of hardware to implement a ZFS on Linux CentOS 7 KVM/Qemu host. This has worked really well but I haven't put any effort in to expanding the configuration to share storage via SRPt or iSCSI Targets even though these options are possible.

Having made the jump from VMware to KVM/Qemu on CentOS 7, I wouldn't look back.

Tom

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Tom,

That is very helpful. Thank you very much for such a full response!!! I will take a look at KVM/Qem

Greg