English version of my posts.
Few weeks ago, our database virtual machines got randomly failed. There was error message “The CPU has been disabled by the guest operating system. Power off or reset the virtual machine.” on VM events. I didn’t find any abnormal on vmkernel, hostd and vm logs. Finally our Linux team identified it’s a Linux kernel bug. Please refer to BUG at block/blk-core.c:NNNN! in blk_requeue_request or blk finish_request.
The bug only present on RedHat 6 on ESXi 5.5 with VMware Paravirtual SCSI drivers.
There are lot of articles tell how to install and setup Nginx + PHP-FPM + MYSQL. But few talk about how to secure WordPress website on the infrastructure. If you are a Windows guy, you perhaps familiar with ACL, it’s similar in Linux world. A user or group has 3 essential permission: read, write or execute. Read this article to understanding how permission works on Linux.
It’s been a while since last technical post. I was pretty busy on preparation of holiday maintenance plan as well as few problems in virtual environment. There was one I’d like to share as it’s a sample to show how to ‘touch’ hardware layer from virtual layer. 🙂
My blog finally backed online!! Due to a updating issue on PhotoVPS infrastructure, my virtual machine ran into unstable since Monday. I didn’t notice it till Wednesday. The virtual machine got intermittently network connectivity issue, PhotoVPS engineers can only temporarily fix it. I was struggled by the situation, finally I decided order a new virtual machine on Krypt. Krypt is ideally place for me since they are VMware certified partner, they helps VMware improves vCloud products and develops in public cloud market. The network performance is also the greatest from North American to China in US service providers, they have dedicate bandwidth to China Telecom.
You probably will see similar issue below if you upgrade vCenter Server from 5.x to 5.5.
vSphere Client show following error when login to vCenter Server by domain account.
The vSphere Client could not connect to vCenter server. The server vCenter server took too long to respond. (The command has timed out as the remote server is taking too long to respond.)
Some people say China government blocked Google. But I think it’s not blocked. Chinese user is suffering a extremely slow access speed to Google websites actually. I guess China government reduced bandwidth to Google since I can access Google.com in my late night time.
Few days ago, VMware sent an email notification to me that my blog was award to vExpert 2014. I would thanks Sean’s reference and suggestion. I’m very glad to hear that news! It encourage me continue contribute to virtualization community, share my experience with people. Here is the link lists my name and Twitter account. … Read more
Some critical VMs got blue screen in last few weeks. After working with OS and hardware vendor, we figured out the root cause eventually. It’s a CPU problem related to Intel v2 CPU of E3, E5 and E7 families. The detail information is documented in VMware KB Windows 2008 R2 and Solaris 10 64-bit virtual machines blue screen or kernel panic when running on ESXi 5.x with an Intel E5 v2 series processor.
There is a dash vulnerability on Debian, please following the steps below to check your system:
In my post HP Blade Firmware Upgrading Best Practices for ESXi Host I mentioned HP released firmware and drivers by SPP image. I have set my ESXi 5.5 baseline to SPP2014.06 as I have tested it in my lab environment. Looks like stable.
