The Ubuntu Mainframe Cookbook
If you liked the Virtualization Cookbooks for Red Hat and SUSE and you are looking at Ubuntu right now then maybe you are interested in Mike MacIsaac’s latest book: The Ubuntu Mainframe Cookbook.
virtualization
Example for using Apache Spark on the mainframe
This YouTube video from Paul DiMarzio shows an interesting analytic example from the Hack Spark contest. Thanks Paul for creating this!
Middleware / application testing – operating system, hypervisor and hardware
After the IBM statement of directions to support KVM on System z I’ve been asked many times for a criteria if a certain ISV software or customer solution needs to be retested or not. As in performance the answer is: … Read the rest
Updated Whitepaper: WebSphere Application Server – Idle Server Tuning
When running in a virtualized environment like z/VM it’s beneficial if the hypervisor knows if a server is idle or not. Usually this is implemented by waiting a certain time before considering a server truly idle. The problem is that … Read the rest
z/VM 6.3 preview
Today IBM announced a preview of z/VM 6.3. The two top improvements are:
- 1 TB memory
- HiperDispatch
At SHARE there have been two presentations with more technical details in it:
- z/VM performance update (starting at page 57)
- z/VM Platform
40 years VM – happy birthday!
40 years ago IBM introduced VM/370 the first virtualization layer. My first really brief encounter was at the end of the 80ies, when I did some RPG programming work. But I learned the real value of it a decade later, … Read the rest
DB2 Connect high CPU utilization
DB2 Connect servers are usually a good target for consolidation. Recently we observed relatively high CPU utilization even though only a small workload was being used. The oprofile and strace output showed that the system was busy doing semget() calls … Read the rest
New Whitepaper: “Java Design and Coding for Virtualized Environments”
Ever wondered why your Java application is not running as smooth as it should in a virtualized environment? There are multiple reasons for this and so Steve Wehr gives some explanation for this in this new whitepaper. This isn’t … Read the rest
Updated Virtualization Cookbook
The virtualization cookbook from Michael MacIsaac, Brad Hinson, Marian Gasparovic received a major updates to cover z/VM 6.2 (including singe system image), RHEL 6.2 and the upcoming SLES11 SP2. All is now in one book and it’s even got a … Read the rest
Why doesn’t the Linux iowait show up as busy time in the virtualization layer?
When a process in Linux has issued an IO and is waiting for a response there are basically two different possibilities. The good case is that there is other work pending and the CPU can continue to work. If there … Read the rest