This time I would like to tell how to configure this subject, in a particular each separate component as a result to receive the own, expanded, otkazoustoycheavy cloud based on OpenNebula. In this article I will consider the next moments:

• Install Ceph, distributed storage. (I will describe the installation of a two-tier storage with a caching pool of SSDs)
• Install MySQL, Galera Cluster with master replication
• Installing OpenvSwitch soft switch
• Installing directly OpenNebula itself
• Configuring Failover Cluster
• Initial configuration

The topics themselves are very interesting, so even if you are not interested in the final goal, but you are interested in setting up a separate component. You are welcome under the cut.

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I decided to try ZFS here the other day, but I did not find a detailed and simple manual on how to implement it on CentOS, I decided to correct the situation. In addition, I wanted to install all this in EFI mode. - not to stand still? And at the same time understand for yourself how DKMS works, as well as aspects of manual installation of RPM-based distributions. ZFS was not chosen by chance either, since it was planned to deploy a hypervisor on this machine and use zvol to store images of virtual machines. I wanted something more than a software raid + lvm or simple file storage of images, something like ceph, but for one host this is too bold. Looking ahead to say that I was very pleased with this file system, its performance and all its chips.

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Previously, I quite often had a situation where you simultaneously work in a terminal and, for example, in a browser. After several hours of work, you start to get confused and in the terminal instead of [Ctrl] + [Shift] + [C], press [Ctrl] + [C], and vice versa in the browser. As a result, in the terminal you get an interrupt and in the browser, instead of the expected effect, your debugger is slowly loaded. One fine moment it got me and I decided it was time to change something…

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To date, there are quite a few ways to forward a USB device to another computer or virtual machine over the network.

Of the most popular, hardware such as AnywhereUSB and purely software products, from those that I tried myself: USB Redirector and USB / IP.

I would like to tell you about another interesting method that works directly with the QEMU emulator.

It is also part of the spice project, officially supported by RedHat.

UsbRedir, is an open protocol for forwarding usb-devices via tcp to a remote virtual server, developed with the support of RedHat in the framework of the spice project. But as it turned out they can be quite successfully used without spice. The server is usbredirserver, which fumbles a usb device on a specific port, and QEMU itself as a client, which emulates the connection of an exported usb device to a specific usb controller of your virtual machine. Thanks to this approach, absolutely any OS can be used as a guest system, since it does not even know that the device is remotely forwarded, and all the logic rests on QEMU.

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If you still do not know what Kolab is, then you probably want to read the first article, where I did a detailed review of this rather functional and completely free mail server with a beautiful web-muzzle. This time we will install it.

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Hi, Habr! I want to tell you about a rather interesting and functional replacement for MS Exchange, completely free and also with a beautiful web-muzzle. The conversation will be about Kolab - a free mail server with support for collaboration, calendars, to-do lists, WebDAV, ActiveSync synchronization and other goodies that can be used both for work and for home.

Carefully, in a post a lot of pictures…

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I want to tell you about how having your VPS server on the Internet, you can raise a tunnel to your home network. And do not pay at the same time for a static IP provider, and even being behind a NAT, still make your home services available on the Internet.

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