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I’ve spent a good part of the last 2 weeks working on a Linux (RHEL) based OBIEE integration project, involving CA Siteminder Single Sign On integration. I did find a sleugh of “how-to”, Oracle documents, and forum articles, but none of them combined the pieces that someone brand new to the technology and application might need to troubleshoot and discern common problems that typically arise. My intention is to put together a comprehensive guide (read “from scratch) on how to deploy, configure and integrate the these two products and how to be up & running in under 60 minutes -ok, give or take a few minutes here and there 
Cheers!
Miguel Pereira.-
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If you are like me, and just getting your feet wet with Oracle, I bet you will at some point yourself in this situation. You’ve installed Oracle, brought up the Database Console, and gone Rambo on it: configuring what you thought had to be configured, setting default values here and there. And what it one of the very first things that we, as DBAs, tend to focus on first? Backups. Indeed, we are fed the concept that a solid backup & recovery strategy is so essential, that we sometimes fail to address the ‘solid’ aspect. Meaning, we need to ensure that what we are doing is: efficient, effective & applicable to our environment. After all, why would you setup tape backups if you don’t have a tape device to back up to, right?
Well, again, if you are like me…
One of my first Oracle 10g instances was installed and configured about 9 months ago -at least one of the first ones of a data center environment. This instance has a nice fiber attached storage slice to dump all my disk backups. And I thought I was doing the right thing when I went through Database Console, and under the Backup Policy told it to have a MAXPIECESIZE of 2GB -little did I know setting this up was going to haunt me later. Why? Because I inadvertedly changed the setting under the TAPE device policy section.
I did this after I had taken my initial backups -after deploying the first schemas & tablespaces. So when I came back a few weeks later to check on my backup jobs, I was stocked to see that I was running dangerously low on my flashback recovery area -which is also used to store backups and archive /redo logs. I thought, piece of cake, let me take an full backup and tell it to clear all archive logs after the fact. Then I can delete my backup sets adnd voila.
Well, my RMAN backup script kept on erroring out showing the following:
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library
Little did I know -or understand- that this was of my own making. My first KB searches (read google) for that specific ORA error landed me on Veritas / Symantec support forums. Specifically for cases where DBAs were actually having problems with TAPE devices. That was no good. I was taking backups to DISK. So I continued on my hunt. Determined to fix this. So far it was Oracle 1 – Miguel 0. It couldn’t stay that way.
Then, I landed on the following forum: http://www.orafaq.com/forum/t/61699/0/ which eventually took me here http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96566/rcmconfg.htm#451806
Clearing Channel and Device Settings
To clear a configuration is to return it to its default settings. You can clear channel and device settings by using these commands:
- CONFIGURE DEVICE TYPE … CLEAR
- CONFIGURE DEFAULT DEVICE TYPE CLEAR
- CONFIGURE CHANNEL DEVICE TYPE … CLEAR
- CONFIGURE CHANNEL n DEVICE TYPE … CLEAR (where n is an integer)
Each CONFIGURE … CLEAR command clears only itself. For example, CONFIGURE DEVICE TYPE … CLEAR does not clear CONFIGURE DEFAULT DEVICE TYPE. The CONFIGURE DEVICE TYPE … CLEAR command removes the configuration for the specified device type and returns it to the default (PARALLELISM 1).
So, I checked my own RMAN configuration:
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| $RMAN target /
RMAN> show all;
using target database control file instead of recovery catalog
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE SBT_TAPE TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 4 BACKUP TYPE TO COMPRESSED BACKUPSET;
CONFIGURE DEVICE TYPE SBT_TAPE PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE CHANNEL DEVICE TYPE DISK MAXPIECESIZE 2 G;
CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' MAXPIECESIZE 2 G;
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default |
What is that? CONFIGURE CHANNEL DEVICE TYPE ‘SBT_TAPE’ MAXPIECESIZE 2 G is not a default value. So, let’s get rid of it. How? Easy
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| RMAN> CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' CLEAR;
old RMAN configuration parameters:
CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' MAXPIECESIZE 2 G;
old RMAN configuration parameters are successfully deleted |
Now, let’s try to backup or crosscheck old backups again that oughta take care of you. Remember, read the documentation. I am starting to find that its a lot more effective to manage Oracle instances through the OS console instead of Database Control Web UI. Good luck!
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Out goes one more icon of the rock scene. Ronnie James Dio left this world on May 16th, 2010 after battling stomach cancer since November of 2009. A tremendous loss for the music world, and a much bigger one for Dio’s wife, Wendy. Our deepest condolences.
http://en.wikipedia.org/wiki/Ronnie_James_Dio#Cancer_and_death
 Ronnie James Dio (July 10, 1942 – May 16, 2010) Share on Facebook
I just finished building my second media center PC. This time, I opted to go the open source route and decided to take MythDora for a spin. MythDora is a Fedora-specific build of the open source MythTV project.
MythDora is a Fedora and MythTV Linux Distribution that provides all the tools necessary to create a working MythTV based PVR system. MythDora is available in I386 & X86_64 architectures on both LiveCD and DVD formats.
I built this on a box with the following specs:
Nothing fantastic specswise, but sufficient. As this very same hardware had been running my Vista and most recently Windows 7 Ultimate MCE setup. FYI: since then replaced with an Athlon II X4 + 8GB DDR3 + Win 7 64-bit -a rocketship!
Back to MythDora though. The setup was rather painless. Though I was not so much interested in the install process but in how simple it was going to be to setup the tuner USB stick & how much grief was a Linux flavored media center going to give me. After all, I don’t want to build something that will require technical skills to run every day. I want my wife or myself for that matter to be able to turn it on and enjoy our recorded shows. Well, the first answer is: not too shabby; I was able to get the Pinnacle USB tuner up & running within 30 minutes after figuring out how Linux was naming the device (/dev/blah blah blah). Note: a quick way to figure out if the firmware has been loaded correctly on linux:
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| $dmesg grep -i warm
$dmesg grep -i 801se |
An hour later, I had a working MythDora frontend up & running. I ran a couple of live TV recording tests, and it held up fairly nice. There are some kinks I think could be worked out on the front end, where if too many commands are issued while a show is being recorded, the interface will stop responding. The show will still play & record, even if the front end is killed, but that can turn into an annoyance -remember: fire and forget is the objective.
But let’s move past that, the one thing that really took me by surprise was that this open source MC was picking up more channels OTA using the same antenna connection -it’s up in my attic- as the Windows 7 MC. Strange. I don’t have any theories, unless there is a better implementation in software to clean up signal cross-over on Linux than Windows. If you have a theory or factual information, please don’t hesitate to share it. So far, I have been unable to find anything concrete.
In the end, I think I will keep this MythDora thing around for a bit. I think if I can get a cheap -but decent- ATSC tuner on eBay or perhaps NewEgg, I can justify keeping it around until it burns. It will let me record shows on it without annoying my wife. And it has a really neat built in web-interface that allows you to do pretty much everthing you can think of: add, edit & delete scheduled TV recordings, view TV listings, stream recorded shows, download full quality recorded shows (MPG format, no encoding), perform maintenance activities such as mySQL table re-indexing, cleanup & queuing up recorded shows for commercial removal / tagging & transcoding.
I gotta wait until I can start scourging eBay though. Been too trigger happy in the past few months buying parts and upgrades. But the bottom line is, I am starting to dig Linux more and more.
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I can’t believe how out of date I am on the consumer / workstation technology world. Turns out that there is an incredibly easy way to make yourself a bootable USB flash drive with Windows 7, ready to install. The answer: Windows 7 USB/DVD Download Tool. It’s a handy-dandy utility provided by Microsoft, through their Online Store intended to allow a legitimate software owner, to download an ISO image of it’s favorite operating system -Windows 7- and turn that into a working, bootable, USB-flash based installer.
Here is the piece of advise though: be wary of the download manager offered by Microsoft. Yes, it does seem to pick and choose the best download source based on server load, but it does have a nasty tendency of corrupting downloaded files. I had to waste 6 hours today re-downloading the 3GB image of Windows 7 64-bit. The one I had originally downloaded from the store was corrupted, though I could still open it without issue with tools such as WinRAR. How did I realize I had a bad image? When I burnt and tried to install Win7 again, and received the following install error: “Required CD/DVD device driver is missing”. That prompted me to waste time trying to find the “driver” and change countless settings on my BIOS unnecessarily. Had I known that the ISO downloads were so prone to be corrupted, I would’ve started there.
You have been warned!
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