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Building vmware-tools in your Oracle Linux UEK3 VM

This is a quick writeup of an oddity I found while trying to install the vmwareware tools in an Oracle Linux host with the UEK3 kernel enabled (which is by default).

This is what is encountered during the vmware tools installation dialog when running vmwaretools.pl:

Searching for a valid kernel header path...
The path "" is not a valid path to the 3.8.13-16.2.2.el6uek.x86_64 kernel 
headers.
Would you like to change it? [yes]

The building of vmware tools fail because the kernel headers can not be found: the installer doesn’t see the kernel headers, whilst you probably installed it (it’s the kernel-uek-devel package belonging to the running kernel).

Playing with Application Continuity in RAC 12c

One of the more interesting features in Oracle 12c RAC is application continuity. Why do I believe it is? Because it relieves developers from having to think about retrying connections and catch SQLExceptions in the code. I already thought that Fast Application Notification and Fast Connect Failover (FCF) are great, _but_ they required the developer to understand RAC and Oracle which you can’t take for granted. In fact looking back over the last few years since I co-wrote Pro Oracle Database 11g RAC on Linux the number 1 complaint I got from developers was that RAC was too complex (see for example in this thread on oracle-l)

Now Application Continuity takes away 2 problems I have seen.

Be aware of these environment variables in .bashrc et al.

This is a quick post about one of my pet peeves-statically setting environment variables in .bashrc or other shell’s equivalents. I have been bitten by this a number of times. Sometimes it’s my own code, as in this story.

Background

Many installation instructions about Oracle version x tell you to add variables to your shell session when you log in. What’s meant well for convenience can backfire. Sure it’s nice to have ORACLE_HOME, ORACLE_SID, LD_LIBRARY_PATH, CLASSPATH etc set automatically without having to find out about them the hard way. However, there are situations where this doesn’t help.

Upgrading to Oracle Linux 6.5

This is a very short post to demonstrate how to upgrade to Oracle Linux 6.5. My lab system was reasonably current, Oracle Linux 6.4 with some security patches (but not all). The upgrade to 6.5 (or “latest”) is very simple, and since Oracle announced they had beefed up connectivity it’s a real joy. Instead of 450kb/s I get around 9 MB/s. For those of you who want the ISO image: you can’t currently get it from edelivery, the only update method is YUM/ULN or you download the ISO from My Oracle Support, patch 17860279.

Hard Drive Predictive Failures on Exadata

This post also applies to non-Exadata systems as hard drives work the same way in other storage arrays too – just the commands you would use for extracting the disk-level metrics would be different.

I just noticed that one of our Exadatas had a disk put into “predictive failure” mode and thought to show how to measure why the disk is in that mode (as opposed to just replacing it without really understanding the issue ;-)

Inside a RAC 12c GNS cluster

Based on some reader feedback I started looking at GNS again, but this time it will be for RAC 12c. According to the documentation GNS has been enhanced so that you can use it without subdomain delegation. I decided to try the “old fashioned” way though: DHCP for VIPs, SCAN IPs, subdomain delegation and the like as it is the most complex setup. I occasionally like complex.

The network setup is exactly the same as I used before in 11.2 and thankfully didn’t require any changes. The cluster I am building is a 2 node system on Oracle Linux 6.4 and the Red Hat compatible kernel. I have to use this as the Unbreakable Kernel doesn’t know about block devices made available to it via virtio-scsi. I use virtio-scsi for shared block devices very much in the same way I did for Xen.

Drill Down the I/O stack at UKOUG Tech13

It's just under a week to go before the doors open for the UKOUG Tech13 conference and the adjoining OakTable World UK 2013 sessions, so I thought I would write a very short blog post about what I will be doing there, where I'll be, and what I'm looking forward to. This year I will […]

Drill Down the I/O stack at UKOUG Tech13

It's just under a week to go before the doors open for the UKOUG Tech13 conference and the adjoining OakTable World UK 2013 sessions, so I thought I would write a very short blog post about what I will be doing there, where I'll be, and what I'm looking forward to. This year I will […]

When the Oracle wait interface isn’t enough

Oracle has done a great job with the wait interface. It has given us the opportunity to profile the time spend in Oracle processes, by keeping track of CPU time and waits (which is time spend not running on CPU). With every new version Oracle has enhanced the wait interface, by making the waits more detailed. Tuning typically means trying to get rid of waits as much as possible.

Applying PSU 12.1.0.1.1 in the lab environment

Since the first patch for Oracle 12c has been made available I was of course keen to see how to apply it. For a first test I opted to use my 3 node RAC cluster which is running on Oracle Linux 6.4 with UEK2. This post is not terribly well-polished, it’s more of a log of what I did…

The cluster makes use of some of the new 12c RAC features such as Flex ASM but it is not a Flex Cluster:

[oracle@rac12node3 ~]$ srvctl config asm
ASM home: /u01/app/12.1.0.1/grid
Password file: +OCR/orapwASM
ASM listener: LISTENER
ASM instance count: 2
Cluster ASM listener: ASMNET1LSNR_ASM
[oracle@rac12node3 ~]$

My database is a standard 3 node administrator managed build: