VERITAS Storage Foundation 4.1 for Oracle RAC HP Serviceguard Storage Management Suite Extracts, December 2005
Using Storage Mapping
8
The storage mapping feature is available with SFRAC and enables you to map datafiles to
physical devices. To obtain and view detailed storage topology information, use the
vxstorage_stats command or the VERITAS Storage Foundation for Oracle GUI. You
can also use the Oracle Enterprise Manager to access storage mapping information.
Understanding Storage Mapping
Access to mapping information allows for a detailed understanding of the storage
hierarchy in which files reside. This information is critical to effectively evaluate I/O
performance.
Mapping files to their underlying device is straightforward when datafiles exist directly
on a raw device. With the introduction of host-based volume managers and sophisticated
storage subsystems that provide RAID features, mapping files to physical devices is more
difficult.
With the VERITAS Storage Mapping option, you can map datafiles to physical devices.
VERITAS Storage Mapping relies on VERITAS Federated Mapping Service (VxMS), a
library that assists in the development of distributed SAN applications that must share
information about the physical location of files and volumes on a disk.
The VERITAS Storage Mapping option supports the Oracle set of storage APIs called
Oracle Mapping (ORAMAP) that lets Oracle determine the mapping information for files
and devices.
Oracle provides a set of dynamic performance views (v$ views) that show the complete
mapping of a file to intermediate layers of logical volumes and physical devices. These
views enable you to locate the exact disk on which any specific block of a file resides. Use
these mappings, along with device statistics, to evaluate I/O performance.
The VERITAS Storage Mapping option supports a wide range of storage devices and
allows for “deep mapping” into EMC arrays. Deep mapping information identifies the
physical disks that comprise each LUN and the hardware RAID information for the
LUNs.
View information on storage mapping topology and I/O statistics using:
153