Oracle: Unbreak my Linux Heart

MySQL created a TCO (Total Cost of Ownership) calculator showing how cheap MySQL is compared to Microsoft MSSQL and Sybase. Interestingly, the parent company Oracle remains out of this picture. I find that sad. Why not be open and let the customer decide? Either way, the savings of MySQL Enterprise Edition to MSSQL are shocking: MySQL TCO Savings Calculator . Add your grain of salt...

Dell has released a statement about ubuntu 11.10 on Dell PowerEdge . Dell lists that Ubuntu should work where the previous versions also worked and is currently re-certifying most PowerEdge and PowerEdge-C servers. Check Canonical's hardware certification page for details. Also good to know is that OpenManage (OMSA) has been released for Ubuntu , although it is not officially supported.

pxeconfig : With pxelinux, which is a derivative of syslinux, you can specify with a PXE configuration file how the node must boot. This configuration is placed in, e.g. /tftpboot/pxelinux.cfg directory

Dell TechCenter posted a very easy "how to get started" guide for KVM Virtualization that you may find useful if you're just getting started and know little or nothing about virtualization (in Linux or elsewhere). It's good for the basics.

Dell TechCenter has released a LiveDVD image with OMSA to update firmware and BIOS on Dell hardware using a CentOS Linux distro.

Dell's released the latest version of OpenManage 6.5.1 . It provides drivers, BIOS and firmware updates from Linux when running Dell PowerEdge hardware.

My OEL4 servers still have duplicate RPM packages on 64 bit servers. Libs for 32 bit and 64 bit are often installed, even though they may not always be used. When upgrading a package, such as glibc, you run into the error that yum won't touch a package because it finds duplicates. In this case you can try Removing Duplicate RPM Packages or remove a package using an explicit architecture tag: yum package.{i386,i686,x86_64} such as yum remove glibc.i686 . If you have RHEL/OEL5 or higher, you're in luck because you can try to install the package yum-utils and run package-cleanup --cleandupes . yum-utils offer a bunch of useful tools for working with yum repos and so on.

EMC (VMware) has a great technical webcast and PDF online about Performance and Provisioning for Virtualized Oracle . I highly recommend you listen to it or read the sheets. Very informative if you want to use virtualized Oracle databases in a production environment. Most set-ups of virtualizing Oracle databases on VMware fail because storage I/O becomes a bottleneck. It turns out, 50% of all surveyed set-up had storage configured wrong. The problems has to do with storage queues in the VM and subsequently on the ESX host. Additionally, vSphere 4.1 introduces features ( SIOC ) to optimize the I/O better to the SAN and para virtualized SAN drivers can further reduce latency and increase throughput. Then the webcast also mentions Oracle's "native" NFS client ( dNFS , PDF) inside the database kernel. This reduces the CPU overhead and latency normally observed on NFS client in the OS. By using Oracle's native NFS client, you can use shared storage in a grid computing envi...

We had a strange issue during Oracle WebLogic development yesterday. Setting up a secure connection between a client and the WebLogic Admin server took really long on our shiny new hardware (Dell R710) compared the older servers (Dell 2950). After we made sure everything was exactly the same, people started to blame C1 and C1E states and other powersave or cpu throttling measures. However, given the different in setup times (2-6 sec vs 50-90 sec), I suspected it to be something else. Throttling down from 2.23 GHz to 1.6 GHz cannot cause such a great difference. Or at least be unlikely. Lo and behold, it turned out to be related to the seeding of the random number generator in Java. Normally this is linked to /dev/random but can be sped up by using /dev/urandom , which uses some entropy of your system. Still, the urandom device, while faster, still caused a 20-fold difference. As a workaround, you can tell your JVM which seed generator to use and prevent JVM from waiting or looking or ...

The kind people of the German university of Göttingen have mirrored the Dell OMSA hardware and firmware repo for us. This way, we have a European mirror available that is also much faster than Dell's native server.

Dell has released version 6.5 of their OpenManage repository with firmware and BIOS updates as well as Linux monitoring of hardware found in Dell servers.

Dell's OMSA is great for maintaining and updating a Dell server's firmware, if it works... Dell does a great job so far, but sometimes little quirks mess up small parts and suddenly OMSA will update all or nothing or only a few and then call it quits. pjwelsh has written a handy little summary of the various ways with which you can try to still get working, albeit manually: Failed BIOS update on Dell R710 with CentOS 5.5 solved! (Worked around, really)

Dell recently published a little more details about what Ubuntu Certified and Ubuntu Ready means . Even though Dell does not officially support Ubuntu, their hardware is labelled as Certified by Canonical and they can also provide with paid support for Enterprises that require it.

Besides having the option to download installation media from Oracle (for which you must register), you can use the Oracle Public Yum Server to get packages. For instance, to help solve ad-hoc dependencies. This alleviates you from the need to keep a local mirror available for all Linux releases.

Also found this great but slightly dated resource on Tuning Journaling File Systems . We had a crash of a VM recently with 3 million small files in a single directory. Tuning some mounts with noatime and dir_index helped a lot. Still tinkering with journaling options, though.

A few days ago, Oracle followed suit by Red Hat and released OEL6. Here are the Oracle Linux 6 Release Notes . At first glance, most notable changes are default ext4 file system. Better performance monitoring and tracking using perf and new user space "top" tools, and it no longer uses up2date but instead relies totally on yum. Yummie! Last but not least: the Unbreakable Kernel kernel-uek-2.6.32-100.28.5.el6 is installed and activated by default! This shouldn't matter much, unless you run the latest state-of-the-art hardware and use SSDs a lot. But 3rd party software vendors may like you stepping away from the Red Hat default kernel-2.6.32-71.el6 kernel. So check first! OL6 is the first Linux distribution from Oracle where they no longer patch the Red Hat kernel. Instead, they provide the Red Hat kernel as-is as an option to be configured for use in /etc/grub/menu.lst. The default kernel in OL6 is the Unbreakable Enterprise Kernel that Oracle maintains itself. As far...

Linux uses 512-byte sectors. Hard disks used to too. The emergence of huge TB-sized disks has caused manufacturers to changed to 4096-byte sectors. This change can cause performance degradation on Linux as it's partitions may not be aligned with these bigger sectors. The additional overhead for the disk causes a performance drop. This raises the need for aligning your Linux partitions to the new sector size. However, many tools such as fdisk and parted are not yet doing this for you easily. IBM DevWorks has a great in-depth article on the topic: Linux on 4KB-sector disks: Practical advice

I knew I could use fdisk in Linux to create partitions for me from a script. This can come in handy during kickstart for (re)deployment of a server and you don't want to let anaconda handle partitions for you. Or you simply want to be absolutely sure things go as you want, instead of relying on software with unknown bugs or quirks. I knew you can use something like: fdisk /dev/sda to partition /dev/sda for you with one large partitions and give it type 8e (LVM). (The 'q' is so that those who simply copy this, don't immediately wipe some disk.) But I was looking for somewhat cleaner, more intuitive style. James Stephens pointed out the use of sfdisk from scripts . While I don't know if sfdisk is less reliable than fdisk or parted, or how to handle byte-aligning disks [ 1 ] [ 2 ] [ 3 ] from these scripts, it's a good place to start and I wanted to document it here.

Oracle Linux 5.6 makes Unbreakable Enterprise Kernel the default kernel after installation unless you perform a custom installation. Note that Unbreakable Enterprise Kernel is available for the x86_64 platform only. The Unbreakable Enterprise Kernel is delivered via the package kernel-uek .

Dell Community : "RHEL 6 provides SR-IOV functionality on supported hardware which provides near native performance for virtualized guests. Single-Root I/O Virtualization (SR-IOV) specification, introduced by PCI-SIG details how a single PCIe device can be shared between various virtualization guests. Devices capable of SR-IOV functionality support multiple virtual functions on top of the physical function. Virtual Function is enabled in hardware as a light weight PCIe function. Operating System cannot discover this function as it does not respond to the PCI bus scan and requires support in the host’s driver. As in PCIe pass-through, a Virtual function of a SR-IOV capable card can be directly assigned to the guest operating system. A virtual function driver running in the guest manages this device."