I see a lot of questions on shared file systems that can be used when people move from single instance to Oracle RAC database and Grid Infrastructure. The most common question is the following: “Should I place archive logs in OCFS2 or ASM or ACFS of 11g?” I’ll try to clarify this topic below.
First we need to understand a separation between Oracle database files and non-database files. Read more »
In this article I continue listing common database configuration issues that can affect Oracle database high availability (HA) causing unplanned downtime. Make sure you read the first part of Oracle database configuration issues that cause downtime.
Control file limit reached
This issue can occur when you reach limits of some DB configuration parameters stored in a control file like MAXLOGFILES, MAXLOGFILEMEMBERS, MAXINSTANCES.
To fix this you need a downtime. 10g has reduced some of those limitations though.
Oracle ASM instance limits
Oracle ASM can be considered as another database instance that have own parameter limitations you also need to consider carefully. Read more »
A well-designed high availability (HA) solution accounts for all these factors in preventing unplanned database downtime. One of the true challenges in designing a highly available (HA) solution is examining and addressing all the possible causes of downtime. It is important to consider causes of both unplanned and planned downtime. The diagram shown in the slide, classifies unplanned database failures.