Exadata Hardware - Oracle Exadata Recipes: A Problem-Solution Approach - page 26

Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2

These logical volumes are mapped to /dev/mapper devices:

[root@cm01dbm01 ~]# ls -ltar /dev/VGExaDb/LVDb*
lrwxrwxrwx 1 root root 28 Feb 20 21:59 /dev/VGExaDb/LVDbSys1 -> /dev/mapper/VGExaDb-LVDbSys1
lrwxrwxrwx 1 root root 29 Feb 20 21:59 /dev/VGExaDb/LVDbSwap1 -> /dev/mapper/VGExaDb-LVDbSwap1
lrwxrwxrwx 1 root root 28 Feb 20 21:59 /dev/VGExaDb/LVDbOra1 -> /dev/mapper/VGExaDb-LVDbOra1
[root@cm01dbm01 ~]#

How It Works
Each Exadata compute node in the Exadata X2-2 and X3-2 models contains four 300 GB SAS drives controlled with an
LSI MegaRAID controller. Host operating system file systems are mounted from Linux logical volumes, which are built
using volume groups that are based on the physical devices.
For the root and /u01 file systems, Oracle elected to employ the Linux kernel device mapper to map physical
block devices to logical device names, which enables flexibility with logical volume management. Oracle does not,
by default, use all of the physical space available; the volume groups have excess capacity, allowing an Exadata
administrator to expand the size of /u01 if necessary, create LVM snapshots for backup and recovery purposes,
and so forth.

1-6. Listing Flash Storage on the Exadata Storage Servers
Problem
As an Exadata administrator, you wish to better understand how flash storage is configured and presented on an
ExadataStorage Server.

Solution
In this recipe, we will show you how to do the following:

lsscsi • Query your SCSI flash device information using

flash_dom • List your PCI flash module configuration using

fdisk
From the storage server host's point of view, you can see your flash devices using lsscsi :

• List your flash disk partition information using

[root@cm01cel01 ~]# lsscsi -v|grep MARVELL
[8:0:0:0] disk ATA MARVELL SD88SA02 D20Y /dev/sdn
[8:0:1:0] disk ATA MARVELL SD88SA02 D20Y /dev/sdo
... Flash disks omitted for brevity
[11:0:3:0] disk ATA MARVELL SD88SA02 D20Y /dev/sdac
[root@cm01cel01 ~]#