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I'm starting to deploy oVirt in one of my works, and I have a lot of questions about how to manage everything when you start using it.

First I'll describe my setup. I have three machines, two ProLiant DL360e Gen8 servers and one common PC. All of them have 1TB of storage available for the OS, and have the same partition scheme. Following this tutorial and it's second part, I've managed to setup the three machines as follows:

Clusterized storage with gluster and CTDB exporting four volumes: engine, isos, data and meta. Meta is used to maintain coherence among the cluster, engine is used to store oVirt's hosted engine data, data is used to store VM's images and isos to store iso images for OS vm provisioning.

Hosted engine has been set up in both ProLiant servers.

What I was looking for with this setup is to be able to keep on running VM's even whith one of the ProLiants being down. So I had to set up a third machine for storage, that way, I would not lose quorum in the exported gluster volumes if one of the ProLiants goes down.

Everything seems to be working fine. So let me ask a few questions:

  1. Wich is the recommended way to make backups of the hosted engine and VM's, so I can recover from disaster??
  2. I have four NIC's in each server and two in the PC. Right now I'm using just one interface in each machine. Wich would be the recommended network setup for this scenario? I'm buying a new managed gigabit switch next week, so I will be able to have VLAN's working with this machines!!
  3. Whis is the recommended way to bring the hosts down for maintenance??? One at a time and all togheter??
  4. All the equipment is connected to a single APC SmartUPS, and I've setted up apcupsd on another host that is network connected with these three machines. Which is the recommended way to bring them all down really quickly in an event of power failure??? (I have around 35 minutes of autonomy with this UPS for the whole setup!)
  5. Reading around, I do not remember where, I remember that someone stated that in oVirt it was recommended to leave the default datacenter and cluster as they were, and start configuring everything in a new datacenter. I remeber trying to do that, but not being able to accomplish it, because the hosts (the ProLiants) where already memebers of the default cluster, so I've started to set up my VM's in the default cluster. Is this wrong??? I do not know if I missed something important with this.

Finally, please excuse my bad english! It's not my native language!

Thanks everyone in advance!!!

Luciano César Natale
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1 Answers1

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  1. engine backup is done using a script aptly called engine-backup. Backing up VMs is trickier, there's a built-in API[1] but it will only be effective if you're using a host OS that is capable of libvirt blockcommit, i.e. latest Fedora or EL7.1. Otherwise, you can backup the VMs the old fashined way, using in-agent backups or stopping them to take a backup, if downtime isn't critical.

  2. I would bond all 4 NICs using mode-4, if the switch can support that, and segregating the network into a management VLAN, VM network, display network and storage network. If you expect storage loads to interfere, maybe break that down into two bonds, one for storage and one for VMs, display and mgmt

  3. One at a time. When you click the "maintenance" button, all VMs from the host will migrate away, so the host can be taken down. Storage connections, during maintenance are also getting shut down.

  4. Whatever the UPS vendor recommends, this has nothing to do with oVirt. Basically, the pre-shutdown procedure would be to take all VMs down first (so the UPS might want to trigger an API script that would issue shutdown on all VMs) and then place all hosts in maintenance, so they can be shutdown cleanly. When all hosts are in maintenance, it is safe to pull the plug

  5. Not wrong and not right either. In the older versions, there were some hard dependencies that could break if you deleted the default stuff. Using the defaults wasn't a problem. Since it's still better to have everything properly named, it is recommended to create your own DC and Clusters. To move a host between clusters, put it in maintenance, edit and change the cluster affinity. Activate the host - and it's in the new cluster.

Welcome to the wonderful world of oVirt :)

[1] http://www.ovirt.org/Features/Backup-Restore_API_Integration

dyasny
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  • Soon much easier in VMware ;) – ewwhite Feb 19 '15 at 21:59
  • And much more expensive ;) – dyasny Feb 20 '15 at 01:34
  • ewwhite, thanks for your opinion, but as dyasny says, oVirt has no cost other than hardware and work! dyasny, thanks for your long and detailed answer! I'll try to implement the things you wrote! One question, When I put a host in maintenance, if I issue the command `hosted-engine --vm-status` is says that it's in local maintenance, and the hosted engine starts migrating to the other host. Is that because I'm using the default datacenter and cluster? Or that's the way it's always supoused to be? Thanks a lot! – Luciano César Natale Feb 20 '15 at 16:17
  • @LucianoCésarNatale Well, if you put a host in maintenance, that means you might take it offline, or even delete it, so regular VMs as well as the hosted engine should be migrating away to other available hosts. – dyasny Feb 20 '15 at 16:28
  • Ok!! I'll be trying to implement this stuff next week and I'll tell you how it goes! – Luciano César Natale Feb 22 '15 at 16:15
  • Hey @dyasny, I'ven been playing with this stuff, I've finally got the new sitch, and I'm having a very hard time to set this up. I don't know why, but the engine's web interface is extremely slow now. After trying to set up the new network configuration manaully in one of the ProLiants, I've discovered that the only way to do it safely is through the web interface, but it took a lot of time to do it, because of this unresponsivness problem. The weird thing is that everything seems ok, the hosts are not overloaded, and neither is the engine VM. So how can i debug this response/speed problem?? – Luciano César Natale Mar 05 '15 at 19:53
  • Please don't tell me you are accessing the web interface from an old browser like ie9 – dyasny Mar 06 '15 at 00:30
  • jaja no no... I'm using chrome and firefox from linux notebook. But it's important to note that it used to work fine. I started looking at the requests that the browser makes with the debugger, and a lot of xhr asynchronous requests take a lot of time to be responded by the server... I banging my head against the wall with this... – Luciano César Natale Mar 06 '15 at 17:07
  • try to clean cache and cookies etc. if that doesn't help, you need to email users@ovirt.org, might be a bug – dyasny Mar 06 '15 at 20:08
  • Found what was wrong... The hosted engine had a bad DNS setup... Brutal mistake. Finally I have the servers working with the bonded interfaces!!! This week i'll try to set up the backups and all other stuff!!! thanks a lot dyasny! – Luciano César Natale Mar 08 '15 at 21:43