Developers Club geek daily blog

Yes you zadolbat the information society

1 year, 3 months ago

Disk with music. Almost like AudioCD works.

Let's assume, you want to send the red line message to the colleague. Today you send mail, the message to social networks or the SMS.

We go down below on stories. What was before? Fax. It was analog of modern e-mail: the message was transferred instantly, got out of the device and was ready to reading.

We go more deeply. There are no fax and phone now too. You send the telegram. Just serious cable nodes were forced out from a bigbon by phones. The exchanges learned news telegrams. The British journalists from the farthest doomsday reported data the teletype. You could telegraph for any person on a meeting which would be carried by the special boy on your mail switch, and then the second boy – from other local switch to the addressee. Almost like cellular network, only a ping is more.

We continue travel. We disconnect electricity, the first logs, first imperceptible appear. Here in Prague full-fledged pneumomail works. Wrote a feather the letter, dried sand and blotting paper, put in a special capsule. Vzhukh! The capsule departed on other end of the city. By the way, if to vykolupat optics from the trunk, it will be possible to arrange pneumomail in a protective tube so partially backward compatibility is saved.

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Why I recheck the written data, or History of one investigation …

1 year, 4 months ago
Recent habrastatya about distinctions in byte by byte identical files caused from memory depths (and a mailbox) a small piece of my correspondence with one of the engineers who were responsible at that time for the line of the disks MPG in the Fujitsu company. For convenience of English nonspeaking readers, I give transfer from English under a cat.

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FlexPod Express: UCS-Managed configuration

1 year, 4 months ago
Among three previous configurations of Small/Medium/Large in architecture of FlexPod Express one more appeared under the name Cisco UCS-Managed. In this article the speech about this new configuration will go. FlexPod Express and FlexPod Datacenter are divided into two main types of connection: direct connection of SHD to servers (between SHD and servers there is no switch) or via the switch (between SHD and servers there is a switch), I will remind that Fabric Interconnect is not the switch, but part of the UCS domain of servers.

It should be noted several important differences of a new configuration from previous three.
  • First in architecture there were Fabric Interconnect, let also performed by the internal devices installed in the UCS Mini chassis with blades.
  • Secondly in architecture the possibility of direct connection of SHD to Fabric Interconnect appeared, earlier between servers and SHD there shall be a switch. At the same time the switch had to be only Nexus (3048/3500/9300).
  • In the third if we have a configuration of FlexPod Express Cisco UCS-Managed with direct connection, the switch for connection of ultimate users shall not be Nexus. Now it can be any standard switch maintaining fault tolerance on similarity of Multi Chassis Etherchannel. But if between UCS and FAS the switch is necessary, then the switch is obliged to be Nexus.

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The NetApp company declared purchase of SolidFire

1 year, 4 months ago
NetApp, inc signed the agreement on purchase of SolidFire, inc for 870 million a dale. USA cash.

Founded in 2010, SolidFire is a vendor of All Flash of storages for DPC of new generation where "configured simple scaling and management in a type and forgot" provides performance and the joint Multy-Tenancy environment.

With SolidFire NetApp will give the new sentence which will cover each of three parts of the All Flash market of storages:

  • For traditional infrastructures of Enterprise of customers, NetApp All Flas FAS (AFF), a product line which provides functions and possibilities of Enterprise of level.
  • For owners of applications, NetApp EF a series of the products showing incredibly high values of performance at the same time low speed of a response (Latency) according to open testing SPC-1, and also high availability "six nine".
  • For customers with infrastructures of new generation, the products from SolidFire distributed, self-repairing and the extending architecture, reasonable price and simple management.

SolidFire is active in cloudy community and provides to integrate an uravleniye storage by means of VMware vCenter plug-in, VAAI, SRM, OpenStack driver, CloudStack plug-in, Microsoft VSS provider, PowerShell, VMware SRM/SRA and other cloud solutions.

Through time products of SolidFire will be integrated into a paradigm of NetApp DataFabric providing seamless management of cloudy resources, and also the flash-resources and disk arrays.

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As the flash memory will change structure of data-centers

1 year, 4 months ago
In our blog on Habré we not only tell about development of a cloud service 1cloud, but also we write about new technologies much, including in the field of processors and memory. Today we present to yours adapted translation of a note of the engineer of the Altera company Ron Wilson how development of technology a flash memory can change structure of the data-centers existing nowadays.

Perhaps, there comes the turning point in the history of data-centers. Already for many years tanks a flash memory increase that allows us to expand constantly possibilities of our phones, cameras and mediaplayers.

Emergence of new solid-state drives with use a flash memory allowed to begin development of more modern tablets and notebooks. Such drives began to appear also in data-centers.

Imperceptibly for us, the speed of emergence of new technologies sharply increased. NAND flash memory with new vertical architecture exceeded characteristics planar a flash memory, having allowed to store considerable data volumes in each crystal. New non-volatile technologies, for example memory of Intel-Micron 3D Xpoint, already begin to come to mass production.

You should not forget also about hard drives which technologies also continue to develop. Result of all this will become unprecedented change of structure of data-centers which will begin with hyper scalable clouds, but will gradually reach also the enterprises.

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Loukost a hosting of dedicated servers in Russia. Whether it is possible?

1 year, 4 months ago

In last article with similar heading, we told and even proved that loukost the hosting of virtual servers (VPS) in Russia is possible. But how the situation with lease of dedicated servers is? Whether it is possible to hand over in Russia servers at the prices Hetzner-and, providing to clients gigabit channels?
We decided to carry out small analytics and to try to give the answer to post heading. Also we created a loukost-configurator of dedicated servers based on the equipment which is available for us. What from this left – you learn now.

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Proxmox VE 4 installation of the root section on unsupported the soft raid1 installer

1 year, 4 months ago

Starting with version 3.6 in the Proxmox installer there was an installation option on different ZFS Raid options, but did not appear, used by many, a configuration with an arrangement of a root and storage area of disks of virtual computers on program raid an array.
On Habré and in a network there is a set of similar articles, but they are actual for version 3,6, and in version 4.0 several interesting nuances appeared. Besides in this instruction I will approach a solution of this task absolutely some other way.

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Quickly lifted it is not considered fallen. We increase fault tolerance of the built-in systems

1 year, 4 months ago

A year ago performed quite interesting work on development of the built-in computer for one enterprise which is engaged in electronics. The computer represented nothing essentially interesting: the Cortex A-8 processor working at subgigahertz frequencies, 512Mb as DDR3, 1Gb NAND, lightweight assembly of Linux. However the device which the computer was built in, so and to him should work in quite severe conditions. Broad temperature range (from-40 to +85 Celsius degrees), moisture resistance, resistance to electro-magnetic radiations, kilovoltage impulses on power supply, protection against a statics in 4 kV and a lot of things interesting that is well described in different state standard specifications on special equipment, – all this about it. One of the main requirements of the customer – development term on failure not less than 10 years. At the same time the vendor provides warranty repair of a product within five years therefore a question not rhetorical, but monetary and serious. In a product the corresponding element base was mortgaged. The device with honor passed tests and received required certificates, but conversation not about that. Problems began when the installation lot was produced, and devices dispersed on departments and CB for creation of application software. Returns with the formulation went: "Something is not loaded".

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Evolution of data structures in Yandex. To a metrics

1 year, 4 months ago
Yandex. A metrics today it not only system of web analytics, but also AppMetrica — system of analytics for applications. On an input in the Metrics we have a data stream — the events which are taking place on the websites or in applications. Our task — to process these data and to present them in the form, suitable for the analysis.

But data handling is not a problem. The problem is in that as well as in what type to save results of processing that it was possible to work with them conveniently. In development process we had to change approach to the organization of data storage several times completely. We began with the tables MyISAM, used LSM trees and eventually came to column-oriented to the database. In this article I want to tell what us forced to do it.

Yandex. The metrics works since 2008 — more than seven years. Every time change of approach to data storage was caused by the fact that this or that solution worked too badly — with an insufficient stock on performance, it is insufficiently reliable also with a large number of problems at operation, used too many computing resources, or just did not allow us to implement that we want.

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Experience of testing of ScaleIO

1 year, 4 months ago

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