System logs on host are stored on non-persistent storage

I tested a brand new DELL PowerEdge R620 as a cloud hypervisor with an ESXi 5.0 installer. The new servers have only a dual SD cards as internal storage, instead of a SAS or SSD disc. If you try something new, you should have trouble configuring it in an old way. I got a new warning message after the hypervisor installation: System logs for host [hostname] are stored on non-persistent storage.
Continue reading “System logs on host are stored on non-persistent storage”

How-To create backups of running vApps in VMware vCloud version 5.1 and earlier

With vCloud version 5.5 the Director (web GUI) got a bunch of useful features. One of them is Cloning Running vApps: page 9 – 2.2.3 Clone vApp with Memory State

With older deployments of vCloud administrators still have to use the REST API to create these hot-clones. From the vCloud Director the only option to clone a vApp is to stop that first, which method is simply unacceptable in production environments.

When developing automated backups, or auto deploying vApps/networks the REST API-based scripts come handy even with newer versions.

Let’s take a look at the API through a few simple examples.

Continue reading “How-To create backups of running vApps in VMware vCloud version 5.1 and earlier”

Minimalistic docker: starting from scratch

Next generation Linux distributions are out. Significant changes create special flavour by comparing to other unix-like derivatives.
In spite of implementation of similar features, the distance and the diversity
are growing. Sounds good, isn’t? Not all share this opinion.

Docker is one result of the actual virtualization trends on Linux. The control
groups (aka cgroups) realize features which make sense to use operating
system level virtualization, the one kernel many containers scenario.

Conditions, environment
X86 virtual machine deployed on VMware ESXi 5.5 on HP DL360Pg8.
Minimal Oracle Enterprise Linux 7 installed on 2 CPU cores and 4 GB.
No RAID on VM level, LVM and xfs for the general filesystems (default).
Extra softwares added: screen, wget and vim.
EL7 contains systemd and the Oracle kernel is used 3.8.13-44.el7uek.x86_64, dtrace is available.

First steps and look
Installing and configuring docker on OEL7 is quite easy. Continue reading “Minimalistic docker: starting from scratch”

More is not always better – CPU ready in VMware vSphere

You might have a situation, when your 2 vCPU webserver is having a high load (although CPU usage in MHz is normal).

In this situation most administrators would add extra vCPUs to the server, and expect to have an enhanced performance.

Unfortunately the additional vCPU can actually degrade performance. Let me explain why.

Continue reading “More is not always better – CPU ready in VMware vSphere”

Configuring vSwitch ports

When people use standard vSwitches in vSphere it is always a problem, at least for me how

to configure switch security policies like promiscuous mode, or mac address changes just

for a few ports where these required. Using the standard vSwitch I always created a new

portgroup just for the few VMs which require special policies, but this is not the best

way, and really not a perfect solution.

If people change to use distributed vSwitches, and yes, if people has money for such

license this prblem could be solved much easier.

By default with a distributed vSwitch the same settings are defined at the portgroup

level, and the settings are inherited by all the ports. But this can be overridden if

required. To do so at first the override of the security settings at port level must be

enabled in the portgroup advanced settings tab.


After this, the inherited port settings can be changed.


Now, we have a port with custom port security policy. 🙂