Overview of ASMCMD

In most scenarios, when ASM is configured as a storage unit for Oracle databases, a SAN administrator prepares the required storage (LUNs) from the storage array and then presents the disks (raw disk) to the host. In turn, system administrators configure the device files for the presented disks and notify the DBAs about the availability of the disks. However, once the disks are presented to an Oracle ASM system, there is no direct method available which would allow either SAN administrators or system administrators to hold any control over the contents or on the utilization of the disks. Fortunately, the ASMCMD, a command-line utility that was first introduced in Oracle ASM version 10g R2, provides the functionality to query/navigate/view/operate an underlying filesystem inside the ASM.

Although, the ASMCMD operations were limited in the beginning to a few tasks, its functionality has been extended significantly in Version 11g R1 and 11g R2. It can now be used to repair...