You may see following error in Cisco UCS Manager: default Keyring’s certificate is invalid The reason is Admin -> Key Management -> KeyRing default is expired. It’s not possible to delete or change the KeyRing in GUI. You have to log in to SSH of Cisco UCS Manager and run following commands (The strings after … Read more
A few days ago, I deleted some older firmware packages in Cisco UCS Manager. Suddenly more than 100 warnings were generated. The error messages are similar below: blade-controller image with vendor Cisco System Inc……is deleted Cause: image-deleted Clearly, it’s triggered due to packages deletion. But all of my service profiles and service profile templates were … Read more
Some notes for LXC. CentOS 7 minimal version doesn’t support LXC installation by default since LXC is deprecated in version 7. The new container solution is based on docker framework. There is an alternative to install LXC. Following are procedures: Install Epel (Extra Packages for Enterprise Linux) repository. # yum install epel-release Install some dependencies. … Read more
There is an issue been identified in VMware Tools 10.3.0 can result in a PSOD or guest network connectivity loss. VMware has released KB57796 for that.
I got following error message when I try to run KVM Virtual Machine Manager: virt-manager on SSH. Gtk-WARNING **: cannot open display: There are several things need to be checked: Make sure “X11Forwarding” is set to “yes” in /etc/ssh/sshd_config on the machine you run virt-manager. cat /etc/ssh/sshd_config | grep “^X11” If you are using Windows to … Read more
When you load a PowerShell script you may see following error messages: Timed out waiting for the PowerShell extension to start If you see error logs, following appears: The language service could not be started One possible reason is your PowerShell executive policy is set to “AllSigned“. You can find the policy by run PowerShell … Read more
You may see “The IP address to reach the server is not set” when clicking the KVM console in Cisco UCS Manager. The issue persists even Cisco UCS Manager has enough IP addresses for management. Re-acknowledge or reset CIMC cannot fix the problem. The fix procedure is go to “Equipment” -> Select the server -> … Read more
In recent LAB environment reviewing, I noticed my LAB ESXi hosts allow connections from all IP address for NTP services. This is not the best practices for the solid environment. I want to specify certain IP addresses are allowed in case of vulnerabilities in NTP services. There are a lot of blogs talking about how … Read more
If you are still using Windows 2008 for vCenter Server. You may see ESXi hosts lost connection back and forth on vCenter Server after recent Windows pathing. It’s not something like a heartbeat lost for a few seconds. ESXi can takes minutes to back online. You can see similar logs in vpxd.log: 2018-08-03T09:24:23.337-04:00 error vpxd[20160] … Read more
Disk Interface IDE (ATA): Bandwidth is 133 Mbps. IOPS is ~100. The interface can connect maximum 2 disks. SCSI: IOPS is ~ 150. It can connects 8 or 16 disks Ultrascsi320 – 320 MB/s Ultrascsi640 – 640 MB/s SATA: Bandwidth is 6 Gbps. IOPS is ~150. It can connects to 8 or 16 disks. SAS: … Read more
