For a very long time, fixing MySQL slaves was a tedious task. Slaves died, replication fails, tables would get out of sync and you’d have to import all the (consistant) data from the master database. Depending on the importance of the slave, this could mean downtime for your master while exporting.

MySQLdump is usually the application one uses to execute this task, locking the tables while exporting. For me, having a database readonly, is downtime. However you look at it, if your website is not 100% useable, it is experiencing downtime.

I came across Percona’s xtrabackup utility a while back … Read more


When using the “Simple Install” to install a new vCenter setup, you might encounter the following error when trying to register the vCenter server to the Web interface:

The vSphere Web Client Administration Tool only supports registration of vCenter Server version 5.0. For newer versions, the vCenter Server system must be registered with the Lookup Service to allow the vSphere Web Client to discover the system.

To resolve this, follow these steps:

  • Log in to the vSphere Web client as the admin account (admin@System-Domain) you created during the vCenter server installation
  • Browse to “Administration -> SSO Users and Groups”
  • Browse
Read more

I had a corrupted IOS image on a 3750E switch today and feared for a xmodem transfer to eat up my day, until I found that you can copy from TFTP. It’s very well hidden, but still possible. Here’s how:

When the switch has ‘booted’ without a proper IOS, you’ll be in the ‘switch: ‘ command line. In the following example, I will assume that the TFTP server has IP 192.168.0.10 and the switch will use 192.168.0.1.

Connect your TFTP server to the ethernet management port, then follow this sequence:

switch: set IP_ADDR 192.168.0.1/255.255.255.0
switch: set DEFAULT_ROUTER 192.168.0.10
switch: copy
Read more


VMware just announced a new addition to their vCloud product family; vCloud Integration Manager.

vCloud Integration Manager was developed to provide a simple and standardized way for service providers to provision vCloud Director, vShield and vSphere in order to more quickly get new customers up and running on a cloud service. Until now, service providers either had to do these tasks manually, or redirect valuable software development resources to writing undifferentiated “glue code” and/or automation scripts.

Integration Manager reduces operational costs by automatically stepping through the configuration process for vCloud Director to set up Virtual Data Centers, virtual networks, administrator … Read more


Twitter is one of the webservices I deeply admire; simple, easy and scaled to the heavens. They did a review of 2011 with statistics that reaffirm that scalability. A few examples:

  • UEFA Champions League: 6,303 tweets per second
  • MTV VMA: 8,868 tweets per second
  • Steve Jobs’ passing: 6,049 tweets per second

Check the entire list and other 2011 highlights here: http://yearinreview.twitter.com/en/tps.html

Read more

A lot of people are saying the VCAP4-DCA and VCP5 are hard to pass. After taking the VCAP4-DCA late October and the VCP5 late December, I was wondering why there are so many warnings; passing didn’t seem too hard. Maybe it’s the practical vs. theoretical clubs, but if you administer an enterprise or service provider VMware environment using several basic techniques like HA, DRS, network or fiber-channel storage, both are really doable.

Either way, to pass these exams, you definitely need to have handson experience. If a test environment is not an option, explore on the environment you do have … Read more


When installing various VMware products that link into vCenter (vShield, vCloud Connector, vChargeback, I could go on..), you often have minimal control over what URL is actually used to browse to the plugin and you usually can’t change it later on. This can screw up your SSL certificate plans.

After a little digging, I found these tables in the SQL database:

– VPX_EXT_CLIENT
– VPX_EXT_SERVER

Both have a field called ‘URL’ which has the URL (doh) to the plugin.

Two things; this is not supported by VMware and could break something. I hasn’t on my setup, but it might on … Read more