How to install Oracle Database Cloud Backup Module

I had the joy of using the Oracle Database Cloud backup module a month ago. Needless to say that things changed since last year and some of the blogs posts I found were not relative anymore.

I used the database cloud backup module to take a backup of a local database and restore it in the cloud.

A good start would be this link to the documentation.

The installation is really simple, download the installation (more...)

Oracle Database 12.2 released for Exadata on-premises

We live in exciting times, Oracle Database 12.2 for Exadata was released earlier today.

The 12.2 database was already available on the Exadata Express Cloud Service and Database as a service for a few months now.

Today, it has been released for Exadata on-premises, five days earlier than the initial Oracle announcement of 15th Feb.

The documentation suggests that to run 12.2 database you need to run at least 12.1.2. (more...)

Upgrading to Exadata or later – mind the 32bit packages

This might not be relevant anymore, shame on me for keeping it draft for few months. However, there are still people running an older versions of Exadata storage software and it might still help someone out there.

With the release of Exadata storage software, Oracle announced that some 32bit (i686) packages will be removed from the OS as part of the upgrade.

This happened to me in the summer last (more...)

onecommand fails to change storage cell name

It’s been a busy month – five Exadata deployments in the past three weeks and new personal best – 2x Exadata X6-2 Eighth Racks with CoD and storage upgrade deployed in only 6hrs!

An issue I encountered with the first deployment was that onecommand wouldn’t change the storage cells names. The default cell names (not hostnames!) are based on where they are mounted within the rack and they are assigned by the elastic configuration (more...)

Unable to perform initial elastic configuration on Exadata X6

I had the pleasure to deploy another Exadata in the first week of 2017 and got my first issue this year.

As we know starting with Exadata X5, Oracle introduced the concept of Elastic Configuration. Apart from allowing you to mix and match the number of compute nodes and storage cells they have also changed how the IP addresses are assigned on the admin (eth0) interface. Prior X5, Exadata had default IP addresses set at (more...)

Installing OEM13c management agent in silent mode

For many customers I work with SSH won’t be available between the OEM and monitoring hosts. Therefore you cannot push the management agent on to the host from the OEM console. Customer might have to raise CR to allow SSH between the hosts but this might take a while and it’s really unnecessary.

In that case the management agent has to be installed in silent mode. That is when the agent won’t be pushed from (more...)

Exadata memory configuration

Read this post if your Exadata compute nodes have 512/768GB of RAM or you plan to upgrade to the same.

There has been a lot of information about hugepages and I wouldn’t go into too much details. For efficiency, the (x86) CPU allocates RAM by chunks (pages) of 4K bytes and those pages can be swapped to disk. For example, if your SGA allocates 32GB this will take 8388608 pages and given that Page Table (more...)

Speaking at BGOUG and UKOUG

It’s my pleasure to be speaking at BGOUG and UKOUG again this year.

The coming Wednesday 19th Oct, I’ll be speaking at the UKOUG Systems SIG event here in London (agenda). I’ll talk about Exadata implementations I did last year and issues I encountered. Also, things you need to keep in mind when you plan to extend the system, attach it to ZFS Storage Appliance or Exalytics.

Next is all time my favorite (more...)

OTN Appreciation Day: Oracle Data Guard Fast-Start Failover

Thank you, Tim, for the great idea.

There are so many cool database features one could spend weeks blogging about them.

A feature which I like very much is Oracle DataGuard Fast-Start Failover, FSFO for short.

Oracle DataGuard Fast-Start Failover was one of the many new features introduced in Oracle Database 10.2. It’s an addition to the already available DataGuard option to maintain standby databases. DataGuard FSFO is a feature that automatically, quickly, and (more...)

How to enable Exadata Write-Back Flash Cache

Yes, this is well-known and the process has been described in Exadata Write-Back Flash Cache – FAQ (Doc ID 1500257.1) but what the note fails to make clear is that you do NOT have to restart cell services anymore hence resync the griddisks!

I had to enable the WBFC many times before and every time I’d restart the cell services, as note suggests. Well, this is not required anymore, starting with 11.2.3. (more...)

Extending an Exadata Eighth Rack to a Quarter Rack

In the past year I’ve done a lot of Exadata deployments and probably half of them were eighth racks. It’s one of those temporary things – let’s do it now but we’ll change it later. It’s the same with the upgrades – I’ve never seen anyone doing an upgrade from an eighth rack to a quarter. However, a month ago one of our customers asked me to upgrade their three X5-2 HC 4TB units from (more...)

Grid Infrastructure 12c installation fails because of 255 in the subnet ID

I was doing another GI cluster installation last month when I got really weird error.

While was running on the first node I got the following error:

2016/07/01 15:02:10 CLSRSC-343: Successfully started Oracle Clusterware stack
2016/07/01 15:02:23 CLSRSC-180: An error occurred while executing the command '/ocw/grid/bin/oifcfg setif -global eth0/ eth1/' (error code 1)
2016/07/01 15:02:24 CLSRSC-287: FirstNode configuration failed
Died at /ocw/grid/crs/install/  (more...)

How to resolve missing dependency on exadata-sun-computenode-minimum

I’ve been really busy last few months – except spending a lot of time on M25 I’ve been doing a lot of Exadata installations and consolidations. I haven’t posted for some time now but the good news is that I got many drafts and presentations ideas.

This is a quick post about an issue I had recently. I had to integrate AD authentication over Kerberos on the compute nodes (blog post to follow) but had (more...)

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.


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


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]# ./ -cf Customer-exa01.xml -s 8

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

 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:

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...)