The ramblings of a computer geek
VMWare TPS (Transparent Page Sharing) is a mechanism within the hypervisor to allow the saving of RAM by allowing virtual machines where their memory matches to only store a copy of the memory used once. I.e. If you had 5 Windows 2012 R2 virtual machines running, they are going to be almost completely identical, so … Read more
I had to make some memory changes on a batch of VMs. I didn’t want to have to manually shutdown each VM, alter the memory setting and then restart as this would be very time consuming instead I prepared this script. You first need to create a CSV file, e.g. vmalterlist.csv and place it somewhere on … Read more
What do you do, when you have a virtualised vCenter VM, but you want to adjust something about it without locking yourself out of vCenter. In my case I had a vCenter server that I wanted to adjust the memory on. To do this without locking yourself out, you should follow these steps: 1. First … Read more
If you have a webserver that you want to check, but it requires authentication, you can still perform a check without seeing an error code. So for example, if you had a webserver where you wanted to check that the web server was responding on port 80, but didn’t want to have the plugin login … Read more
The VCSA appliance deployment has changed to be a Microsoft Windows only affair. Unless you perform a few steps first you could end up with the issues below. PROBLEM: During the deployment of the VCSA appliance you get the following error messages displayed: Failed to set the time via NTP. Details: Internal Error. Code 1 … Read more
If you need to determine the IOPS that are being used of the storage by the Virtual Machines you can run a PowerCLI script to connect to the vCenter and then collect the IOPS statistics. The script collects the read/write average IOPS and the read/write maximum IOPS for each virtual machine, because of this the … Read more
If you occasionally need to reboot a Linux box as a one off one evening you can perform the following commands using the at command. Note if you set a time that has just past it will perform the reboot the following day. So lets say its 16:15 and you want to schedule a reboot … Read more
PROBLEM: You need to check if two domain controllers are in sync with each other. SOLUTION: To do this you need to understand a bit about how Active Directory reports if a domain controller replication is in sync. There is something called a UTDV up-to-dateness vector that is basically a number representing what the domain … Read more
You’ll probably find yourself using the message tracking logs to find if an email has gone missing. But what should a normal working mail transaction look like? Well below shows it, where the mailboxes are stored on the same server. EventId Source Sender Recipients MessageSubject NOTIFY STOREDRIVER {} RECEIVE STOREDRIVER fred@sender.com {bob@receive.com} Hello! SUBMIT STOREDRIVER … Read more
In Exchange 2013 you can set an email to be put in the user’s Junk E-Mail folder based on if you think it is SPAM or not. This doesn’t use the Exchange built in spam filtering, it assumes you have a spam filter external to your Exchange environment that can tag an email that it … Read more