Posts

I thought, everyone knows it, but I’m always being asked “Where’s the hardware status tab?” after an update from vSphere 5.x to 6. Many customers still use the vSphere Client (C # client), and steer clear of the vSphere Web Client. To be honest: Me too. I often use the C# client, especially if I do mass operations, or for a quick look at something.

This is really nothing new, the answer is clear. But I think it’s a good idea to write it down. At least for myself. As a reminder to use the vSphere Web Client.

Apparently it’s “how to monitor hardware status” week on vcloudnine.de. Some days ago, I wrote an article about using SNMP for hardware monitoring. You can also use the vSphere Web Client to get the status of the host hardware. A third way is through the vSphere API. I just want to share a short example how to use vSphere API calls and pyVmomi. pyVmomi is the Python SDK for the VMware vSphere API.

The Simple Network Management Protocol (SNMP) is a protocol for monitoring and configuration of network-attached devices. SNMP exposes data in the form of variables and values. These variables can then be queried or set. A query retrieves the value of a variable, a set operation assigns a value to a variable. The variables are organized in a hierarchy and each variable is identified by an object identifiers (OID). The management information base (MIB ) describes this hierarchy. MIB files (simple text files) contain metadata for each OID. These are necessary for the translation of a numeric OID into a human-readable format.  SNMP knows two devices types:

Okay, the headline of this blog post is a bit provocative. This blog post is not written from the vendor perspective. It’s the perspective of someone, who’s sitting between the vendor and the customer. A value-added reseller (VAR) is typically located between vendor and customer. And the business model of a VAR is typically based on selling hardware, software and service.

Added value

The typical customer doesn’t have the time, money and the know-how to transform business requirements into a bill of materials (BOM). It’s a “make-or-buy” decision. And “buy” is often better than “make”. The customer needs a partner who helps him to transform the business requirements into a solution and a BOM.

By default, CentOS 6 comes with Python 2.6. This is a bit outdated, especially if you take into account, that Python 2.7.11, which is the latest Python 2 release, was released in December 2015. If you are new to Pyhton, you will usually start with Python 3. Currently, Python 3.5.1 is the latest Python 3 release. So, Python 2.6 is REALLY old.

Okay, I could use another distro. Ehm… no. CentOS is the is the open-source version of Red Hat Enterprise Linux (RHEL). It was, and it is, designed to be similar to RHEL. CentOS runs only the most stable versions of packaged software. This greatly reduces the risk of crashes and errors. The downside is… Python 2.6. Or Apache 2.2. Or MySQL 5.1. Switching to CentOS 7 is difficult, because there is no inplace upgrade.

Over the last weeks, I’ve tried to improve the performance of my blog. The side was very slow and the page load times varied between 5 and 10 seconds. Much too long! I’ve reduced time consuming plugins, checked the size of pictures, checked CSS and HTML for misconfiguration/ slow clode and tuned the database. The page load times have not really improved.

Yesterday, I checked the httpd.conf on my webserver and found a little typo (accidentally commented line). After a restart of the Apache webserver, the page load times have dramatically improved (down to 2 - 3 seconds). What had happened?

The IT Infrastructure Library (ITIL) is a set of pre-defined processes and common practices (I try to avoid the word “best practice” when talking about ITIL) for the IT service management (ITSM).

When I talk with customers about ITIL, they often complain about the overhead of ITSM processes, that were designed according to ITIL. I already wrote about this in one of my previous blog posts (Is lean ITSM a myth?). Companies mainly have three problems during the implementation and/ or operation of ITIL processes:

The embedded DHCP server on AOS 7 and AOS 8 is a less known feature. But it’s pretty handy in some cases, e.g. if you have no servers on premises, or you don’t want that a a non redundant firewall or router acts as DHCP server. Because you can run two or more switches as a virtual chassis, you can easily make the DHCP server role highly available.

Configuring the DHCP server

The configuration is pretty easy.

HPE StoreVirtual is a scale-out storage platform, that is designed to meet the needs of virtualized environments. It’s based on LeftHand OS and because the magic is a piece of software, HPE StoreVirtual is available as HPE ProLiant/ BladeSystem-based hardware, or as Virtual Storage Appliance (VSA) for VMware ESXi, Microsoft Hyper-V and KVM. It comes with an all-inclusive enterprise feature set. This feature set provides

• Storage clustering
• Network RAID
• Thin Provisioning (with support for space reclamation)
• Snapshots
• Asynchronous and synchronous replication across multiple sites
• Automated software upgrades and self-healing storage
• Adaptive Optimization (Tiering)

The license is alway all-inclusive. There is no need to license individual features.

Representational State Transfer (REST) APIs are all the rage. REST was defined by Roy Thomas Fielding in his PhD dissertation “Architectural Styles and the Design of Network-based Software Architectures". The architectural style of REST describes six constraints:

• Uniform interface
• Stateless
• Cacheable
• Client - Server communication
• Layered system
• Code on demand

RESTful APIs typically use HTTP and HTTP verbs (GET, POST, PUT, DELETE, etc.) to send data to, or retrieve data from remote systems. To do so, REST APIs use Uniform Resource Identifiers (URIs) to interact with remote systems. Thus, a client can interact with a remote system over a REST API using standard HTTP URIs and HTTP verbs. For the data transfer, common internet media types, like JSON or XML are used. It’s important to understand that REST is not a standard per se. But most implementations make use of standards such as HTTP, URI, JSON or XML.