HP XP RAID Manager Software - Manual (Page 168)

Data Protection Facility specifications
Only the permitted volumes can be registered in horcm.conf. When creating the horcm.conf
file, describe volumes only from the view that the host shows. RAID Manager manages mirror
descriptors (Continuous Access Synchronous, Business Copy/MU#0/1/2) as a unit. The Data
Protection Facility has two specifications: one must be a volume that you can see from the host
such as the Inquiry tool, and the other must be a mirror descriptor volume that was registered in
horcm.conf
. The following table shows the registration for the mirror descriptor.
Table 37 Registration for the mirror descriptor
Mirror Descriptor in horcm.conf Volumes in horcm.conf
Business Copy Continuous Access
Synchronous
MU#2 MU#1 MU#0
none E none E none E none E
- - - - - - - - Unknown
- permitted
volumes - permitted
volumes - permitted
volumes - permitted
volumes /dev/rdsk/c0t0d0
- - - - - - - - Unknown
E: Mirror descriptor volume to be registered in horcm.conf.
Unknown: Volumes that own host cannot recognize, even though volumes were registered in horcm.conf.
•
RAID Manager permits operation after the permission command at startup of HORCM.
The target is volume that was registered in the horcm.conf file.
•
The permission command is necessary to permit the protected volume at first. The
permission
command compares an identification for volumes of horcm.conf to all of own
host volumes, and the result is registered within HORCM. And HORCM makes tables for
protected volume and permitted volumes from horcm.conf and Inquiry result. Inquiry result
is based on configuration of Data Retention. When controlling pair volumes, requests to
protected volumes are rejected with error code EX_ENPERM.
•
The Data Protection Facility is based on the host side view at the result of Data Retention. You
need to configure Data Retention before RAID Manager operation. RAID Manager checks
Data Retention by Inquiry within RAID Manager.
•
The Data Protection Facility can be enabled separately for each command device. If you want
to use protection and non-protection modes in the same storage system at the same time, you
can define two (or more) command devices: one with protection ON, one with protection
OFF. Protection mode is enabled for the host that has Data Retention and ON command
device.
Examples for configuration and protected volumes
Case (1): Two Hosts ( Figure 62 (page 169) ). In protect mode Ora2 are rejected to operate the
paired volume, because of Unknown for Grp4 on HOST2.
Case (2): One Host ( Figure 63 (page 169) ). In protect mode Ora1 and Ora2 are rejected to operate
the paired volume, because of Unknown for Grp2 and Grp4 on HOST1. If HOST1 has a protection
OFF command device, then Ora1 and Ora2 are permitted to operate the paired volume.
NOTE: The Data Protection Facility is implemented by only RAID Manager. RAID Manager needs
to know the protection attribute for the command device whether should be permitted the operation
for paired volume. If HORCM has protection ON command device at its time, then HORCM checks
a permission for a paired volume.
168 Data protection operations with RAID Manager