Using Serviceguard Extension for RAC, 6th Edition, April 2008

Create logical volumes for use as Oracle data files by using the same options as in the
following example:
# lvcreate -m 1 -M n -c y -s g -n system.dbf -L 408 /dev/vg_ops
The -m 1 option specifies single mirroring; the -M n option ensures that mirror write
cache recovery is set off; the -c y means that mirror consistency recovery is enabled;
the -s g means that mirroring is PVG-strict, that is, it occurs between different physical
volume groups; the -n system.dbfoption lets you specify the name of the logical
volume; and the -L 408 option allocates 408 megabytes.
If Oracle performs the “resilvering” of RAC data files that are mirrored logical volumes,
choose a mirror consistency policy of “NONE” by disabling both mirror write caching
and mirror consistency recovery. With a mirror consistency policy of “NONE”, SLVM
does not perform the resynchronization.
NOTE: Contact Oracle to determine if your version of Oracle RAC allows “resilvering”
and to appropriately configure the mirror consistency recovery policy for your logical
volumes.
Create logical volumes for use as Oracle data files by using the same options as in the
following example:
# lvcreate -m 1 -M n -c n -s g -n system.dbf -L 408 /dev/vg_ops
The -m 1 option specifies single mirroring; the -M n option ensures that mirror write
cache recovery is set off; the -c n means that mirror consistency recovery is disabled;
the -s g means that mirroring is PVG-strict, that is, it occurs between different physical
volume groups; the -n system.dbfoption lets you specify the name of the logical
volume; and the -L 408 option allocates 408 megabytes.
If the command is successful, the system will display messages like the following:
Logical volume “/dev/vg_ops/system.dbf” has been successfully created
with character device “/dev/vg_ops/rsystem.dbf”
Logical volume “/dev/vg_ops/system.dbf” has been successfully extended
Note that the character device file name (also called the raw logical volume name) is
used by the Oracle DBA in building the OPS database.
Creating RAC Volume Groups on Disk Arrays
The procedure described in this section assumes that you are using RAID-protected
disk arrays and LVM’s physical volume links (PV links) to define redundant data paths
from each node in the cluster to every logical unit on the array.
On your disk arrays, you should use redundant I/O channels from each node, connecting
them to separate controllers on the array. Then you can define alternate links to the
LUNs or logical disks you have defined on the array. If you are using SAM, choose the
type of disk array you wish to configure, and follow the menus to define alternate links.
If you are using LVM commands, specify the links on the command line.
Creating a Storage Infrastructure with LVM 103