How Oracle Works on Exadata - Oracle Exadata Recipes: A Problem-Solution Approach - page 52

Chapter 3
How Oracle Works on Exadata
The unique Exadata software presented in Chapter 2 is what enables Exadata to deliver unparalleled database
performance. This software's features are what sets Exadata apart from non-Exadata platforms; Oracle has released
this software only on the Exadata Database Machine. Experienced Oracle database administrators, Unix/Linux
administrators, and storage administrators may be familiar with how Oracle performs I/O. With Exadata, Oracle has
designed a new I/O communications protocol, changing how I/O is translated from the database instance to the
operating system on which Oracle runs, over the storage interconnect, and to the storage servers.
In this chapter, we will cover how Oracle runs on Exadata and contrast it to non-Exadata database tier platforms
and storage solutions. Readers will walk away from the sections in this chapter with a solid understanding of “how
Exadata is different,” which will help when troubleshooting and will provide a solid base for the information presented
in the upcoming chapters in this topic.
3-1. Mapping Physical Disks, LUNs, and Cell Disks
on the Storage Servers
Problem
As an Exadata DMA, you wish to map the physical disks in an Exadata Storage Server to Logical Units (LUNs) and map
LUNs to Exadata cell disks in order to understand how Exadata's disks are presented as usable storage entities.
Solution
In this recipe, you will learn how to identify your physical disk attributes, map these physical disks to LUNs, and
identify how the LUNs are used to create cell disks. Start by running the following lsscsi command:
[root@cm01cel01 ~]# lsscsi
[0:2:0:0] disk LSI MR9261-8i 2.12 /dev/sda
[0:2:1:0] disk LSI MR9261-8i 2.12 /dev/sdb
[0:2:2:0] disk LSI MR9261-8i 2.12 /dev/sdc
... Remaining 9 SAS disks omitted
[1:0:0:0] disk Unigen PSA4000 1100 /dev/sdm
[8:0:0:0] disk ATA MARVELL SD88SA02 D20Y /dev/sdn
[8:0:1:0] disk ATA MARVELL SD88SA02 D20Y /dev/sdo
[8:0:2:0] disk ATA MARVELL SD88SA02 D20Y /dev/sdp
... Remaining 13 Flash disks omitted
[root@cm01cel01 ~]#