Speaking at Oracle Open World 2014

I’m more than happy that I will be speaking at this year’s Oracle Open World. The first and only time I attended was back in 2010 and now I’m not only attending but speaking as well!

Both with Jason Arneil will talk about what we’ve learned on our Exadata implementations with two of the biggest UK retailers so please join us:
Session ID: CON2224
Session Title: Oracle Exadata Migrations: Lessons Learned from Retail
Venue / (more...)

Speaking at BGOUG 2014 Spring conference

I’ll be speaking at the spring conference of the BGOUG held between 13th and 15th of June. I was a regular attendee of the conference for eight years in a row but since I moved to UK I had to skip the last two conferences. My session is about Oracle GoldenGate – it will cover the basics, components, usage scenarios, installation and configuration, trail files and GG records and many more.

See you there in (more...)

EMDIAG Repvfy 12c kit – troubleshooting part 1

The following blog post continue the EMDIAG repvfy kit series and will focus on how to troubleshoot and solve the problems reported by the kit.

The repository verification kit reports number of problems with our repository which we are about to troubleshoot and solve one by one. It’s important to notice that some of the problem are related so solving one problem could also solve another one.

Here is the output I’ve got for my (more...)

Troubleshooting Oracle DBFS mount issues

On Exadata the local drives on the compute nodes are not big enough to allow larger exports and often dbfs is configured. In my case I had a 1.2 TB dbfs file system mounted under /dbfs_direct/.

While I was doing some exports yesterday I found that my dbfs wasn’t mounted, running quick crsctl command to bring it online failed:

[oracle@exadb01 ~]$ crsctl start resource dbfs_mount -n exadb01
 CRS-2672: Attempting to start 'dbfs_mount' on 'exadb01'
  (more...)

OEM 12c installation fails if parallel_max_servers too high

Just a quick post regarding OEM 12c installation where recently I had to install OEM 12c and during the repository configuration step the installation fails with error:

ORA-12801: error signaled in parallel query server P151

This was caused by a known bug which requires decreasing the number of parallel queries of the repository databases and start over the installation. The database had cpu_count set to 64 and parallel_max_servers to 270. After setting the parallel_max_servers to (more...)

Consider database timezone when created during DST

Not long time ago customer asked me to create new a database and refresh it from production. Nothing special here database was quickly created and then refreshed using network import for few schemas. Few weeks later I’ve been told that the database has a timestamp problem. The date and time were correct but the time zone was different from the production:

SQL> SQL> SELECT DBTIMEZONE FROM DUAL;

DBTIMEZONE
------
+01:00

Looking back I tried to (more...)

RMAN fails to allocate channel with Tivoli Storage Manager

I was recently configuring backup on the customers Exadata with IBM TSM Data Protection for Oracle and run into weird RMAN error. The configuration was Oracle Database 11.2, TSM client version 6.1 and TSM Server version 5.5 and this was the error:

[oracle@oraexa01 ~]$ rman target /

Recovery Manager: Release 11.2.0.3.0 - Production on Wed Jan 29 16:41:54 2014

Copyright (c) 1982, 2011, Oracle and/or its affiliates.   (more...)

Oracle GI 12.1 error when using NFS

I had quite an interesting case recently where I had to build stretch cluster for a customer using Oracle GI 12.1 and placing quorum voting disk on NFS. There is a document at OTN regarding the stretch clusters and using NFS as a third location for voting disk but it has information for 11.2 only as of the moment. Assuming there is no difference in the NFS parameters I used the Linux parameters (more...)

EMDIAG Repvfy 12c kit – basics

Second post in the series of emdiag repvfy kit about the basics of the tool. Having the kit already installed in earlier post it is time now to get some basics before we start troubleshooting.

There are three main commands with repvfy:

  • verify – repository-wide verification
  • analyze - objects specific verification/analysis
  • (more...)

Why my EM12c is giving Metric evaluation error for Exadata cell targets?

As part of my Cloud Control journey I encountered a strange problem where I got the following error for few Exadata Storage Server (cell) targets:

Metric evaluation error start - oracle.sysman.emSDK.agent.fetchlet.exception.FetchletException: em_error=Failed to execute_exadata_response.pl ssh -q -o ConnectTimeout=60 -o BatchMode=yes -o StrictHostKeyChecking=no -o  (more...)

EMDIAG Repvfy 12c kit – installation

Recently I’m doing a lot of OEM stuff for a customer and I’ve decided to tidy and clean up a little bit. The OEM version was 12cR2 and it was used for monitoring few Exadata’s and had around 650 targets. I planned to upgrade OEM to 12cR3, upgrade all agents (more...)

Upgrade to Oracle Enterprise Manager Cloud Control 12c Release 3 (12.1.0.3)

Just a quick wrap up on EM12cR3 upgrade. I have to say that I was pleasantly surprised that everything went so smooth. I didn’t expected anything else, but with so how many products and components we have there I got few things in mind. The version I got was already (more...)

Oracle EM auto discovery fails if the host is under blackout

During Exadata project I had to put some order and tidy up the Enterprise Manager targets. I’ve decided to discover all targets, promote the one which are missing and delete old/stale one. I’ve got strange error and decided to share it if someone hit it. I’m running Oracle Enterprise Manager (more...)

A new beginning

It has been long since my last post and the time has come to resume my postings and refresh my blog. A lot of things happened last few months, I’ve been really busy working on many different projects, graduate university and the very big step – relocate to London with (more...)

Missing IPV6 address for local network interfaces causes service timeout

Year ago I installed Weblogic server + Oralce database server for a customer. Few months later my colleagues asked me whether something has changed in the environment or if something happened at the data center, because they started to see Java exceptions for unknown hostname for a web service they were calling and this was happening only from time to time. We’ve checked the firewall rules, DNS and all the stuff, but everything seemed to be working fine. The only solution by that time they came out was to add the hostname to the hosts file of the Weblogic server. (more...)

How to run standalone Oracle APEX Listener 2.0 with Oracle 11g XE and APEX 4.1.1

This is short guide on how to run standalone Oracle APEX Listener 2.0 beta with Oracle 11g XE. I’m using Oracle Enterprise Linux 5.7 for running Oracle APEX Listener and Oracle Database 11g XE with APEX 4.1.1. Although running APEX Listener standalone is not supported I’m using it to run several internal applications for company needs.

When using APEX Listener with Oracle XE, APEX won’t work properly and white screen appears when APEX is open. This is because the APEX images are stored in the XML DB repository, but APEX Listener have to be run with (more...)

How I run Oracle VM 2.2 guests with custom network configuration

Recently I was given three virtual machines running Oracle Enterprise Linux 5 and Oracle 11gR2 RAC on Oracle VM 2.2.1, copied straight from /OVS/running_pool/. I had to get these machines up and running at my lab environment, but I found hard to setup the network. I’ve spent half day in debugging without success, but finally found a workaround, which I’ll explain here.

Just a little technical notes – Oracle VM (xen) has three main setup configurations within /etc/xen/xend-config.sxp:

Bridge Networking – this configuration is configured by default and it’s simplest to configure. Using this type of networking (more...)

Failed creating physical standby database

These days I’m implementing Oracle Dataguard for two Oracle databases 10.2 as part of disaster recovery project, one of them is around 1.7TB, not yet production. As part of the DG setup backups have to be available for both primary and standby. I preferred to use ASM and was able to negotiate with the storage admin to run storage replication for the FRA disks during the backup. This way I would have the same structure and files, locally at the disaster site immediately after the backup of the primary database is completed.

Unfortunately two weeks passed and by (more...)

Oracle Database 10.2 datapump job fails because of invalid queue

Recently I had to clone one schema from Oracle Database 10.2.0.3 on HP-UX to 10.2.0.4 on Linux. The first problem came when I tried to export it and got the following errors:

UDE-00008: operation generated ORACLE error 31623
ORA-31623: a job is not attached to this session via the specified handle
ORA-06512: at "SYS.DBMS_DATAPUMP", line 2315
ORA-06512: at "SYS.DBMS_DATAPUMP", line 3185
ORA-06512: at line 1

 

These gave me no sign of what could be the problem, but when I tried to export only the metadata I got ORA-00600 which helped me (more...)

Oracle 11g XE listener does not start when there is another database running

If for any reason you have a two databases running on the same server and one of them is Oracle 11g Express Edition then you will get surprised that listener of XE is not started automatically during boot if there is another listener already running. Debugging the startup script I found that this happens because of a bug in the code, which assumes that XE listener is running if it finds the word LISTENER within the processes list.

In file /etc/init.d/oracle-xe, at line 556 the code is failing:

+ status='oracle 2889 1 0 May13 ? 00:00:05 /oracle/ora112se/bin/tnslsnr LISTENER -inherit'
+  (more...)