The Grid Naming Service (GNS) is a new feature in the 11.2 Grid Infrastructure (GI). Its design is to simplify the management of the network configuration of the Real Application Cluster (RAC). When GNS is used, it eliminates the manual allocation of the Node and Single Client Access Name (SCAN) Virtual Internet Protocol (VIP) addresses. […]
Archives for April 2019
Unmounting a Windows Share Fails in Linux
The Problem Unable to unmount a Windows share mount point using umount command. This Windows share is not being used by any processes recently. When executing umount command, following error is seen; # umount: /mycloud: device is busy. (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1)) […]
How to interpret Linux martian source messages
What is a Martian Packet? The IANA defines a Martian packet as one which arrives on an interface where the interface does not use that network. For Linux, it’s any packet that arrives on an interface which is not configured for that subnet in any way. Any martian packet notice should be investigated. Martian packets: […]
Troubleshooting Oracle RAC Node Evictions (Reboots) [ 11.2 and above ]
This post provides a reference for troubleshooting Clusterware node evictions in versions 11.2 and above. NODE EVICTION OVERVIEW The Oracle Clusterware is designed to perform a node eviction by removing one or more nodes from the cluster if some critical problem is detected. A critical problem could be a node not responding via a network […]
Oracle Interview Questions : Grid Infrastructure Single Client Access Name (SCAN)
SCAN Concepts Single client access name (SCAN) is the virtual hostname to provide for all clients connecting to the cluster (as opposed to the VIP hostnames in 10g and 11gR1). SCAN is a domain name registered to at least one and up to three IP addresses, either in the domain name service (DNS) or the […]
How to copy directories recursively using rsync while excluding specific files
Question: How to copy folders recursively while excluding specific folders/files whhen using rsync? In general, we use ‘cp’ command to copy files, but unfortunately, ‘cp’ command doesn’t have the “exclude” feature, so we need to write some scripts to exclude the unwanted files, or we can use another tool ‘rsync’. From the man page of […]
How to Modify an Existing ASM Spfile in a RAC Environment
This post provides an example on how to modify an existing Automatic Storage Management (ASM) spfile in a two-node Real Application Clusters (RAC) Environment. These steps can be applied to a multiple node Real Application Clusters (RAC) Environment. Applies To: Oracle Database – Enterprise Edition – Version 10.2.0.1 to 11.1.0.7 [Release 10.2 to 11.1] If […]
What Happens and What to Do when the SPFILE has been Manually Modified
The Problem The SPFILE has previously been manually edited when the instance was opened. $ ls -l $ORACLE_HOME/dbs/spfileRel14.ora -rw-rw—- 1 sme dba 907 Mar 19 09:17 /ora9i/dbs/spfileRel14.ora a. Once you attempt to store new parameter values, you get the following error: SQL> alter system set processes=70 scope=spfile; alter system set processes=70 scope=spfile * ERROR at […]
How to Install Oracle Linux (UEK-2) with btrfs as a root filesystem
btrfs or Butter FS is a filesystem and has some interesting features: One can have FS snapshots. It is like a freeze of the filesystem at some point of time. btrfs is a extent-based filesystem. This means there are no lists of pointers. btrfs tracks contiguous blocks. btrfs makes checksums of data and metadata. Therefore […]
How to Set Multiple Events in INIT.ORA file
Question: If you have to set more than one event in the init.ora, how can you specify multiple events on the same line? The syntax to specify multiple events in the init.ora is: event=”[event 1]:[event 2]: [event 3]: [event n]” you can also split the events on multiple lines by using the continuation “\” backslash […]