Dead Connection Detection in Oracle Database 12c

In my earlier post I discussed what Dead Connection Detection is and why you should use it – read more here Oracle TNS-12535 and Dead Connection Detection

The pre-12c implementation of DCD used TNS packages to “ping” the client and relied on the underlying TCP stack which sometimes may take longer. Now in 12c this has changed and DCD probes are implemented by TCP Stack. The DCD probes will now use the TCP KEEPALIVE socket (more...)

Oracle Exadata X6 released

Oracle has just announced the next generation of Exadata Database Machine – X6-2 and X6-8.

Here are the changes for Exadata X6-2:
1) X6-2 Database Server: As always the hardware has been updated and the 2-socket database servers are now equip with latest twenty two-core Intel Xeon E5-2699 v4 “Broadwell” processors in comparison to X5 where we had eighteen-core Intel Xeon E5-2699 v3 processors. The memory is still DDR4 and the default configuration comes with (more...)

Oracle TNS-12535 and Dead Connection Detection

These days everything goes to the cloud or it has been collocated somewhere in a shared infrastructure. In this post I’ll talk about sessions being disconnected from your databases, firewalls and dead connection detection.

Changes

We moved number of 11g databases from one data centre to another.

Symptoms

Now probably many of you have seen the following error in your database alertlog “TNS-12535: TNS:operation timed out” or if you haven’t you will definitely see it (more...)

Exadata onecommand fails at cell disk creation

I was installing another Exadata last month when I got an error on create cell disks step. I’ve seen the same error before when I was extending two to three rack Exadata configuration but thought it was one-off.

The cell disk creation failed as below:

[root@exa01db01 linux-x64]# ./install.sh -cf Customer-exa01.xml -s 8

 Initializing
 Executing Create Cell Disks
 Checking physical disks for errors before creating celldisks.........................
 Restarting cell services....................................................
 ERROR:

 Stopping the RS, CELLSRV,  (more...)

Issues with Oracle Direct NFS

This is a quick post to highlight two issues I had with Oracle dNFS. Both relate to wrong entries in the oranfstab file.

One might encounter ORA-00600 during database creation:

DBCA_PROGRESS : 7%
DBCA_PROGRESS : 8%
ORA-01501: CREATE DATABASE failed
ORA-00600: internal error code, arguments: [KSSRMP1], [], [], [], [], [], [], [], [], [], [], []
ORA-17502: ksfdcre:3 Failed to create file /oracle/ORCL/database/ORCL/controlfile/o1_mf_%u_.ctl

This was caused by having a wrong entry in oranfstab (more...)

Come and hear me speak at UKOUG Tech 15

It’s this time of the year again when one of the biggest and last for the year Oracle User Groups is being held and that is UK Oracle User Group Conference.

I’m very grateful and proud that I’ll be speaking on this great conference, here are my talks:

Presentation Title: Oracle Exadata Meets Elastic Configurations
Description: With the release of Exadata X5 Oracle announced Elastic configuration to allow mixed number of db and cell (more...)

How to rename ASM disk groups in Exadata

Deployment of Exadata requires you to generate configuration using Oracle Exadata Deployment Assistant (OEDA). Within the same the default  ASM disk groups names are DBFS_DG, RECOC1 and DATAC1. I usually change those to RECO01 and DATA01 as others doesn’t make sense to me and the only place where I find the default ones is on Exadata.

I had an incident last year where the Exadata deployed half way through and names were left by default (more...)

How to move OEM12c management agent to new location

While working on another Exadata project recently I found that OEM12c agents on the compute nodes were installed on different locations on each of the three Exadatas. On one of them was under /home/oracle/agent, another one had them under /opt/oracle/agent and third one had them under /oracle/agent. Obviously this was not the standard and the agents had to be moved under /u01/app/oracle/agent. The only problem with that was that the three Exadatas were already discovered (more...)

Introducing Oracle ASM Filter Driver

The Oracle ASMFD (Filter Driver) was introduced in Oracle Database 12.1.0.2 and as of the moment it is available on Linux systems only.

Oracle ASM Filter Driver is a kernel module very much like the ASMLIB that resides in the I/O path of the Oracle ASM disks. It provides an interface between the Oracle binaries and the underlying operating environment.

Here are some of the features of ASMFD:

  • Reject non-Oracle I/O

The (more...)

Database system target in pending status for standby database in OEM 12c

That’s not really a problem but annoying issue I had with OEM 12c. Once a standby database is promoted, the database system for the same is showing as metric collections error OR Status Pending.

The standby database doesn’t need its own system since it will join the primary database system. The solution is to associate the standby database with the primary system and then remove the standby database system.

For example – we’ve got primary (more...)

Exadata X5 PDU – CLI already in use

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...)

Start of ‘ora.crf’ failed after update to 12.1.0.2 DBBP7

This happened to me a month ago right after I applied DBBP7 on 12.1.0.2. For some reason the ora.crf resource didn’t start automatically:

CRS-5013: Agent "ORAROOTAGENT" failed to start process "/u01/app/12.1.0.2/grid/bin/osysmond" for action "start": details at "(:CLSN00008:)" in "/u01/app/oracle/diag/crs/exa01db01/crs/trace/ohasd_orarootagent_root.trc"
CRS-2674: Start of 'ora.crf' on 'exa01db01' failed

Checking the trace file for more details you can immediately spot where the problem is:

2015-06-04 10:35:51.156513 :CLSDYNAM:3286230784: [  (more...)

Exadata’s onecommand fails to validate NTP servers on storage servers

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...)

MGMTDB not automatically created on Exadata X5 and GI 12.1.0.2

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 12.1.0.1 and became mandatory in 12.1.0.2 and should be automatically installed with Oracle Grid Infrastructure 12c release 1 (12.1.0.2). For unknown reason to me that didn’t happen and I had to create it manually. I’ve checked all the log files (more...)

dbnodeupdate.sh post upgrade step fails on Exadata storage software 12.1.2.1.1

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 12.1.2.1.0.

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...)

How do I change DNS servers on Exadata storage servers

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...)

How to configure Power Distribution Units on Exadata X5

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...)

opatch 12.1.0.1.7 fails with System Configuration Collection Failed

I was recently upgrading an Exadata 12.1.0.2 DBBP6 to DBBP7 and as usual I went for the latest opatch version which was 12.1.0.1.7 (Apr 2015) as of that time.

After running the opatchauto apply or opatchauto apply -analyze I got the following error:

System Configuration Collection failed: oracle.osysmodel.driver.sdk.productdriver.ProductDriverException: java.lang.NullPointerException
Exception in thread "main" java.lang.RuntimeException: java.io.IOException: Stream closed
 (more...)

Speaking at UKOUG Systems Event and BGOUG

I’m pleased to say that I will be speaking at the UKOUG Systems Event 2015, held at Cavendish Conference Center in London, 20 May 2015. My session “Oracle Exadata Meets Elastic Configurations” starts at 10:15 in Portland Suite. Here is the agenda of the UKOUG Systems Event.

In a month time I’ll be also speaking at the Spring Conference of the Bulgarian Oracle User Group. The conference will be held from 12th to 14 (more...)

applyElasticConfig.sh fails with Unable to locate any IB switches

With the release of Exadata X5 Oracle introduced elastic configurations and changed the process on how the initial configuration is performed. Back before you had to run applyconfig.sh which would go across the nodes and change all the settings according to your config. This script has now evolved and it’s called applyElasticConfig.sh which is part of OEDA (onecommand). During one of the recent deployments I ran into the below problem:

[root@node8 linux-x64]# ./applyElasticConfig. (more...)