Exadata X5-2 and X4-8B racks are delivered with the “Enhanced” PDU metering units connected via the Cisco switch. Although the documentation says they should have static addresses, they don’t. You need to configure them manually using serial console connection, this is described in my earlier post here.
However if you forget to exit the serial console connection to the PDU and then try to login using SSH later you’ll get the following message:
login as: (more...)
There are lots of considerations to be taken into account when migrating databases to the Exadata. It’s like any other migration. DBAs and other stakeholders of the system have to evaluate what to migrate and what not to, physical and logical settings, versions and many other things.
I’m not delving into migration preparation or strategies and methods here, instead I want to mention which method I like the best to migrate databases to the Exadata. By (more...)
I had the pleasure of rebuilding an Exadata rack for a customer a while back, and it provided a pretty good refresher in backup and recovery for me. As DBAs, we back up databases all the time, but the restores are performed much less frequently. In the case of this rack, there were several databases across multiple ASM diskgroups. One of the goals of the rebuild was to consolidate all of the databases into a (more...)
Oracle DBAs who are so old that they remember the days before Oracle 11.2 probably remember the tuning efforts for latches. I can still recall the latch number for cache buffers chains from the top of my head: number 98. In the older days this was another number, 157.
But it seems latches have become less of a problem in the modern days of Oracle 11.2 and higher. Still, when I generate heavy (more...)
Announcing the release of Exachk Version 220.127.116.11.4_20150702. Exachk is a tool that is used to quickly determine the health of the entire Exadata infrastructure. Some of the key components that are checked include the database, cell servers and the network. This tool further reviews the configuration of the system and compares with the best practices. […]
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This is a question that I played with for a long time. There have been statements on logical IO performance (“Logical IO is x times faster than Physical IO”), but nobody could answer the question what the actual logical IO time is. Of course you can see part of it in the system and session statistics (v$sysstat/v$sesstat), statistic name “session logical reads”. However, if you divide the number of logical reads by the total time (more...)
Some time ago Oracle announced that RDBMS 18.104.22.168 has built-in support for JSON processing. A little later it was also mentioned that you have support for JSON in the Exadata storage servers for offloading. This is probably a lot more exciting to users of JSON than it is to me as I’m not a developer. However, whenever an announcement such as the one I’m referring to is made I would like to (more...)
This will be simple and short post on an issue I had recently. I got the following error while running the first step of onecommand – Validate Configuration File:
2015-07-01 12:31:03,712 [INFO ][ main][ ValidationUtils:761] SUCCESS: NTP servers on machine exa01db02.local.net verified successfully 2015-07-01 12:31:03,713 [INFO ][ main][ ValidationUtils:761] SUCCESS: NTP servers on machine exa01db01.local.net verified successfully 2015-07-01 12:31:03,714 [INFO ][ main][ ValidationUtils:778] Following errors were found... 2015-07-01 12:31:03,714 [INFO ][ (more...)
If you’ve run an exachk report, y0u may have seen the following message with regard to your databases:
|FAIL||Database Check||Database parameter CLUSTER_INTERCONNECTS is NOT set to the recommended value||db01:dbm011, db02:dbm012||View|
This check is commonly seen when a database is created on Exadata without using the custom “Exadata” templates included with the database creation assistant. These customized templates include a multitude of recommended parameter settings found in (more...)
While deploying an X5 Full Rack recently it happened that the Grid Infrastructure Management Repository was not created by onecommand. The GIMR database was optional in 22.214.171.124 and became mandatory in 126.96.36.199 and should be automatically installed with Oracle Grid Infrastructure 12c release 1 (188.8.131.52). For unknown reason to me that didn’t happen and I had to create it manually. I’ve checked all the log files (more...)
A lot of blogposts and other internet publications have been written on the full segment scan behaviour of a serial process starting from Oracle version 11gR2. This behaviour is the Oracle engine making a decision between scanning the blocks of a segment into the Oracle buffercache or scanning these blocks into the process’ private process global area (PGA). This decision is even more important on the Exadata platform, because the Oracle engine must have made (more...)
I’ve done several Exadata deployments in the past two months and had to upgrade the Exadata storage software on half of them. Reason for that was because units shipped before May had their Exadata storage software version of 184.108.40.206.0.
The upgrade process of the database nodes ran fine but when I ran dbnodeupdate.sh -c for completing post upgrade steps I got an error that the system wasn’t on the expected (more...)
This is just a quick post to highlight a problem I had recently on another Exadata deployment.
For the most customers the management network on Exadata is routable and the DNS servers are accessible. However in a recent deployment for a financial organization this wasn’t the case and the storage servers were NOT able to reach the DNS servers. The customer provided a different set of DNS servers within the management network which were still (more...)
I’ve done several Exadata deployments recently and I have to say of all the components PDUs were hardest to configure. Important to notice that unlike earlier generations of Exadata the PDUs in X5 are Ehnanced PDUs and not Standard.
Reading the public documentation (Configuring the Power Distribution Units) it says that on PDUs with three power input leads you need to connect the middle power lead to the power source. Well I’ve done (more...)
Another interesting topic that goes over and above the CDB Resource Manager Plans I described earlier this week is the implementation of IORM Plans for Pluggable Databases. Pluggable Databases are an interesting object for studies, and I like to research things. When 12c came out there was no support for offloading initially, it is required that you are on cell software 12.1.x.x.x for full 12c support on Exadata. One aspect I was particularly (more...)