Using Serviceguard Extension for RAC, 8th Edition, March 2009

mirror resynchronization (NOMWC) or fast resynchronization (MWC) for control and redo files
and no mirror resynchronization (NONE) for the datafiles since Oracle would perform resilvering
on the datafiles based on the redo log.
If Oracle does not perform “resilvering” of RAC data files that are mirrored logical volumes,
choose a mirror consistency policy of “NOMWC”. This is done by disabling mirror write caching
and enabling mirror consistency recovery. With “NOMWC”, SLVM performs the
resynchronization.
NOTE: If Oracle resilvering is not available, the mirror recovery policy should be set to either
full mirror resynchronization (NOMWC) or fast resynchronization (MWC) of all control, redo,
and datafiles. For more information on using NOMWC and MWC, refer to the HP-UX System
Administrator's Guide: Logical Volume Management HP-UX 11i Version 3 on
http://docs.hp.com
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.dbf option lets you specify the name of the logical volume; and the -L 408 option
allocates 408 megabytes.
If Oracle performs 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: 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
44 Serviceguard Configuration for Oracle 10g or 11gR1 RAC