Business Copy is an XP256 feature that
allows for copy on demand of selected disk volumes. These volumes
should be grouped as User Volumes, an MPE/iX term. These copied
disks can then be split from their masters and presented to another
HP 3000 machine for off-loading operations such as backup or application
testing.
Business Copy volumes are managed from the internal XP256
PC or from a PC configured as the Remote Control PC.
The software used to manage Business Copy volumes is not currently
available to execute directly from the HP 3000 but requires the
separate PC to function.
Continuous Access is the feature that
allows the XP256 to continuously maintain a copy of a selected number
of disk volumes on another XP256 disk cabinet, located locally or remotely.
This feature is somewhat similar to Business Copy in that
off-loading backup operations or application testing can be performed.
The added value is that the user can use this feature to maintain
a complete working set of data that could be used on the remote
computer in the event of a catastrophic site outage at the primary location.
The software used to manage Continuous Access volumes is not
currently available to execute directly from the HP 3000 but requires
the separate PC to function.
Environment
Business Copy and Continuous Access is supported on MPE/iX release 5.5 with
PPT07 and patch MPEKXL9 and MPEKXT8. It is also supported on
MPE/iX release 6.0 with patch MPEKXL9 and MPEKXT8. For more
information on patches and versions, please contact your support engineer.
Basic Operation
Business Copy and Continuous Access have virtually the same
procedures for setup. System A will "own" data
located on a primary user volume set. A running copy of this data
will be maintained on a Business Copy of the volume set.
At a customer defined time, the user will VSCLOSE the primary user
volume set and then split the primary user volume set from the Business Copy
volume set.
After the split is complete, the user can then VSOPEN the primary user
volume set onto System A and continue operations. System B can now
VSOPEN the split off Business Copy volume set and proceed with its
operations.
Figure 4-1 Basic Setup of Business Copy
System A Procedures
Setup System A
The first time setup requirements are as follows:
Create the Logical Unit Numbers (LUNs) and paths you will use on
the XP256 and then using Sysgen or IOCONFIG create the
LDEVs associated with the paths and LUNs. Make sure to use
HPDARRAY as the ID type. We use the LDEV 60 through 62
for our examples. Test that MPE/iX recognizes the new LDEVs by
either rebooting and running ODE Mapper or if you used
IOCONFIG to issue the commands, use DSTAT ALL.
(MPE/iX Prompt):dstat all
LDEV-TYPE STATUS VOLUME (VOLUME SET - GEN)
---------- -------- --------------------------
60-OPEN-3 UNKNOWN
61-OPEN-3 UNKNOWN
62-OPEN-3 UNKNOWN (MPE/iX Prompt):
Now create the User Volume Set that will be used to off-load
processing. The volume set name for this example is
PRODUCTION_DATA. Use the VOLUTIL utility program to
create the user volume set named PRODUCTION_DATA. Once the
volume set is created, VSCLOSE and then VSOPEN the
volume set before proceeding onward.
Issue the DSTAT ALL command and the following should appear:
(MPE/iX Prompt):dstat all
LDEV-TYPE STATUS VOLUME (VOLUME SET - GEN)
---------- -------- --------------------------
60-OPEN-3 MASTER MEMBER1 (PRODUCTION_DATA-0)
61-OPEN-3 MEMBER MEMBER2 (PRODUCTION_DATA-0)
62-OPEN-3 MEMBER MEMBER3 (PRODUCTION_DATA-0)
Next, create the directory and accounting structure on the system
that will use the User Volume. Be sure to remember to use the proper
syntax and parameters ONVS and HOMEVS
when creating the groups. You are now ready to restore or create the
files that will reside on the user volume set PRODUCTION_DATA.
From the Remote Control PC, configure the LUNs and paths for
the Business Copy volumes and start the copy operation. This takes
about 1 GB per minute depending on your configuration. Once this
operation has completed, you may proceed. At this point you should
have a system configured with a user volume set name
PRODUCTION_DATA and a directory and accounting structure that
is accessible from System B. You should also have a copy of this
volume set maintained by Business Copy. To access the files and
directories when this volume set is "moved" over to System B, you
need to have the identical directory and accounting structure on
System B that is already on System A.
BULDACCT
To access those files on the Business Copy volumes you must
first create the accounts and groups on System B, that
reference the directory structure located on the user volume.
Re-issue the NEWACCT and NEWGROUP commands on
System B or use BULDACCT to create a job stream that
will create the directory for you.
Execute the buldacct utility program and for this example
three accounts exist on the PRODUCTION_DATA volume set.
SALESDB, ORDERDB and STOCKDB.
This will create 2 files BULDJOB1 and BULDJOB2. These
files create the directory structure and re-create the UDC linkages.
Store these files off and restore them to System B. (DSCOPY
can also be used)
System B Procedures
Either re-issue the NEWACCT commands that pertain to
creating the accounts on the system volume set and only those
NEWGROUP commands that you used the parameter HOMEVS or
restore the BULDJOB1 and BULDJOB2 files onto System B
and stream those jobs.
From Sysgen or IOCONFIG issue the commands to configure the
LDEVs of the Business Copy volumes. Be sure that the copy has
completed. If you used Sysgen to configure the volumes you will need
to reboot the system. If IOCONFIG was used, then it will try
to mount the volumes as you add the LDEVs.
Once the volumes are configured and the directory structures are
intact, issue the dstat all command.
(MPE/iX Prompt):dstat all
LDEV-TYPE STATUS VOLUME (VOLUME SET - GEN)
---------- -------- --------------------------
60-OPEN-3 LONER-RO MEMBER1 (PRODUCTION_DATA-0)
61-OPEN-3 LONER MEMBER2 (PRODUCTION_DATA-0)
62-OPEN-3 LONER MEMBER3 (PRODUCTION_DATA-0)
The master volume should say LONER-RO, which means that it is
closed and access is defined as Read-Only. MPE/iX will not let you
mount a Read-Only disk because it is not supported on MPE/iX. The
Read-Only attribute is set by the XP256 while it is active copy
mode.
Business Copy Procedures
On System A
VSCLOSE PRODUCTION_DATA;NOW
This will quiesce I/Os to the volume set and flush all files and data
structures resident to that volume set to disk. Within the Remote Control
PC make sure that the primary and Business Copy disks are in sync and
then split the primary volumes from the Business Copy volumes. (After the
split you may VSOPEN the PRODUCTION_DATA volume set on
System A and continue operations)
On System B
After the primary volumes have been split from the Business Copy you can issue
the VSOPEN PRODUCTION_DATA command on System B and start operations.
When operations are completed, VSCLOSE PRODUCTION_DATA;NOW and from the
Remote Control PC re-establish the primary and Business Copy mode. There is no
need to log off users from System A to re-establish Business Copy.
Continuous Access
The diagram below describes the use of both Continuous Access
and Business Copy to provide both disaster recovery and off loading
of work done by the remote data center.
Figure 4-2 Using Both Business Copy and Continuous Access
The goal is to always maintain a link to the primary volume
set through Continuous Access and use a separate set of disks that
are maintained by Business Copy for planned events like work off-loading.
The process is almost the same as that of Business Copy. First quiesce I/O and
log users off the PRODUCTION_DATA volume set by issuing the
VSCLOSE;NOW command on System A. Then when all data has been moved to
the remote XP256 only then do you split the Business Copy volumes from the
Continuous Access volumes on the remote XP256.
Only when the Business Copy volumes are split on the remote XP256 can System B
VSOPEN its copy of the PRODUCTION_DATA volume set.