Oracle Engineered Systems

Oracle Database Appliance X6-L Memory Expansion – Overwritten HugePage Settings after Reboot

A Customer has extended his Oracle Database Appliance X6-L with Oracle Database Appliance Memory Expansion Kit from 192GB to 384GB. After the first startup, the odacli tool has recognized the additional available memory and gave us the suggested value for the new HugePage settings.

The ODA has the newest available patchset applied, OS is Oracle Enterprise Linux 6.10.

Update the OS Configuration

Oracle suggested the new values for the HugePage settings to 135350MB. 

According the Oracle documentation Oracle® Database Appliance X6-2S/X6-2M/X6-2L Deployment and User’s Guide – Section 13.14 – we updated the OS configuration by odacli. The job was finished after some seconds.

odacli update-osconfigurations (page 13-70)
Use the command odacli update-osconfigurations to update the HugePage and memlock values.

Verfication

The HugePage Settings were updated now.

Time for a hardware restart.

Old HugePage Values after ODA Restart

But, after the machine has started, the old HugePage values were back again. But who has overwritten the settings?

An SR has solved the problem, the are two files in the OS which are responsible for that behavior:

  • /etc/sysctl.d/99-initial-sysctl.conf
  • /etc/sysctl.d/99-oracle-rdbms-server-12cR1-preinstall-sysctl.conf

We take a look at the values:

Solution: Remove these two Files

First, we updated the OS Configuration again.

Second, we removed the files.

Third, we restarted the Oracle Database Appliance.

Finally

HugePage settings are persistent now. By the way, there is an My Oracle Support note for the OS Level 6.10 which describes such a case too:

Changes in sysctl.conf File are not Persistent after Reboot (Doc ID 2477376.1)

Oracle Database Appliance X6 – resize your /u01

Basically on an ODA X6-L the directory /u01 has the size of 100 GB. With seven different ORACLE_HOME directories for the Oracle databases and the Grid Infrastructure software, there is no disk space left for patching the Oracle Database Appliance. ODA patches require between 13 GB and 15 GB free space on /u01 for the new software. Just FYI – during the patch process a new stage directory called /u01/patching is created where the new software is temporarily located.

Patch Apply failed – Not enough free Space

If there is not enough free space available, update processes like updating a database home fail.

Verify the actual Situation and the Disk Configuration

There is not enough free space for the update process – but we see that /u01 is a logical volume. 

Let’s verify the physical volume for free space, we can see 7214 free physical extents are available.

This is the actual size of the logical volume, the actual logical volume size is 100 GB.

Extend /u01

Now we extend online the LVM with the lvextend command from 100 GB to 150 GB.

The logical volume is now 150 GB.

Finally the filesystem has to be resized.

Now we have enough space for patching.

Summary

Resizing the /u01 on an Oracle Database Appliance is very easy and straightforward. There are no special actions required, it’s just a logical volume, no downtime required. And there is more space left on the physical volume for other resize actions.