The ramblings of a computer geek
So I took the plunge on a lease of an electric car, I’ve always been interested in electrically powered transportation, but only now has the battery technology developed to the point where it is 1. practical and 2. cheap enough to do. There’s lots of benefits to the planet, environment and health, and also the … Read more
Here is a cheeky script to drive the API on the Philips Hue lighting system to change the colour of a lamp based on the temperature. That’s right you can colour the light based on the temperature outside, quite neat so you can quickly see if its cold, hot or indifferent just by the colour … Read more
Let’s say you’ve identified a dependency that is needed on your machine, but you don’t know what package will provide the required file, you can use the “yum search <name> | grep <more granular name>” to narrow it down, but to see inside the package before install you can run the below, in my example … Read more
yum install hplip-gui hp-plugin hp-setup Follow the wizard through and setup the USB printer. https://www.centos.org/forums/viewtopic.php?t=62564
In a continued bid to build a desktop Linux machine, I was working on getting the three monitors working. One of the monitors uses the onboard graphics, the other two are plugged into a PCI-E riser card. The issue was that the monitor type is not detected by the onboard graphics, so reports the incorrect … Read more
Whilst building a new home machine I came across this issue where the third screen in my three screen setup was only seen as an “Unknown Display”. My machine has an on-board graphics card and a 2 port PCI-E riser graphics card, the monitors connected to the 2 port riser were working correctly, and the … Read more
If you need to SSH to a host but don’t have direct SSH access, you can perform a reverse SSH tunnel. For this you need a host that will except inbound connections to work as a “jump host”, it is possible without it, where you could SSH back to your client computer; however for the … Read more
PROBLEM As part of a storage replacement programme, we had migrated all our VMs off the NFS datastore. When attempting to unmount the datastore from the host(s) we where given this error: Call “HostDatastoreSystem.RemoveDatastore” for object “datastoreSystem-122544” on vCenter Server “vcenterFQDN” failed. An unknown error has occurred. Checking the /var/log/vmkernel.log on the host we saw … Read more
PROBLEM As part of a storage replacement programme, we had migrated all our VMs off the NFS datastore. When attempting to unmount the datastore from the host(s) we where given this error: Call “HostDatastoreSystem.RemoveDatastore” for object “datastoreSystem-122544” on vCenter Server “vcenterFQDN” failed. An unknown error has occurred. Checking the /var/log/vmkernel.log on the host we saw … Read more
When attempting to migrate a VM from VMware ESXi 5.5. to ESXi 6.0 U1 you may experience problems, this does not affect all VMs only some and they are typically VMs that have been backed up using an external backup tool and make use of CBT (Change Block Tracking). A bug within ESX 5.5 or … Read more