The Disk Library Replication solution is designed to seamlessly replicate data from
remote offices to a centralized data center, where it is stored on disk media
for ready access. Consolidating all backup data at the centralized data center provides
redundancy for disaster recovery, as well as an alternate source for normal data
recovery operations. This innovative solution is easily deployed, without any disruption
of current data protection operations, and with no impact on your end users at remote
offices; no additional software or configuration is required on client computers,
as only MediaAgents are involved.
Even more importantly, the data from every iDataAgent
deployed at remote offices can be replicated to the centralized data center, no
matter the source of the data -- all supported file systems, databases, and data
types.
Significant benefits result when this solution is combined with several other
available features; Deduplication performs deduplication at the remote office before data is replicated
to the centralized data center, greatly reducing the network load; for information
about MediaAgents and data types supported by deduplication, see
Deduplication
- Support.
Replication
Compression provides a similar benefit, compressing data at the remote office,
replicating it across the network to the centralized data center, then uncompressing
it on the destination MediaAgent; finally,
Replication
Encryption can be employed to ensure the security of data transmitted across
non-secure networks, by encrypting the data before transmission and automatically
decrypting it on the destination MediaAgent at the centralized data center.
A
typical Disk Library Replication solution is shown in the illustration.
Software is deployed on a MediaAgent located at a remote office, and
a MediaAgent located at the centralized data center. Thus, there is no impact
on end users and client computers, since all operations involve MediaAgents
only. Deployment and configuration occur once, and the solution continues
to function without any further operator intervention. Once the initial
transfer of data has been completed at the time of deployment, all data
replication after that point will involve only data that has changed on
the MediaAgent, similar in concept to
Incremental Backups. This is different
from an Auxiliary Copy
operation, which is similar in concept to Full
Backups, copying all selected data every time it runs, and also expanding
all deduplicated data each time.
The Disk Library Replication solution replicates data from one MediaAgent to another;
typically, this would involve a MediaAgent installed in a remote office, and one
installed at a centralized data center, although several remote office MediaAgents
can replicate their data to the same centralized MediaAgent. Note that each remote
MediaAgent will require a different mount path on the centralized MediaAgent.
Each MediaAgent computer requires the following:
Meets System Requirements for both
MediaAgent and ContinuousDataReplicator software.
Disk Library Replication
solution is also supported on Windows clustered computers.
The platform on which the software is installed
must be supported for both the MediaAgent and
ContinuousDataReplicator software components.
MediaAgent and ContinuousDataReplicator (CDR) software installed; see
Installation.
Shared Disk Library configured to use replicated disks on both source
(remote office) and destination (centralized data center) MediaAgents; see
Overview of Disk Libraries on Replicated Disks.
In addition, it is recommended that each MediaAgent have the following configured
for this solution:
This section details how to deploy and configure, temporarily disable, or uninstall
the Disk Library Replication solution.
Install, configure, and begin using the Disk Library Replication solution
Install the latest version of the MediaAgent and ContinuousDataReplicator
(CDR) software on a source (remote office) computer and destination (centralized
data center) computer designated for this solution. For step-by-step instructions,
see Installation.
When you have completed configuring the Disk Libraries
on Replicated Disks, a Replication Set with the name "SimpleDataReplication"
and associated Replication Pair(s) will be automatically created, and will
appear in the CommCell Console under ContinuousDataReplicator on the source
(remote office) MediaAgent. The Data Replication Type for the
Replication Set will be set to Disk Library Replication option. For an example of how Replication Sets and Pairs
appear in the Console, see
Tree Levels in ContinuousDataReplicator. It is strongly recommended that you do not attempt to change any settings
in the Properties of these automatically created Replication Sets and Pairs,
except for those discussed in this section.
If you are using Disk Library Replication Solution on clusters, ensure
that the Disk Library Replication option is selected in the Replication
Set (Advanced
tab) on all cluster nodes.
Create a Storage Policy
to be used for this solution, using the Disk Library on Replicated Disks
that you just configured; for general information, see
Storage Policies. It
is recommended that you also enable Deduplication of Data; for instructions,
see Deduplication.
Configure Subclients (new or existing) with the content to be backed up
and replicated to the centralized data center. Make sure to use the Storage Policy you created in the previous step, which will
replicate the data to the Disk Library on Replicated Disks. For instructions, see
Create a New Subclient; for more
information, see Subclients.
Synchronization of data between the source and destination MediaAgents
can be configured by scheduling the replication jobs at desired intervals
using the job scheduler.
Use the following steps to schedule the
replication job:
From the CommCell Browser, navigate to Client Computers | <source_client_computer>
Right-click the Disk Library Replication, point to All
Tasks and then click Backup.
Select the desired Backup Type.
From the Job Initiation, click the Schedule option and
then click Configure button.
Schedule the job as required, from the
Schedule Details
dialog box and then click OK. See
Scheduling for more
information.
Once the installation and configuration is complete on both the source and
destination MediaAgents, replication will begin within the update interval specified
earlier in this procedure.
Temporarily disable and re-enable the Disk Library Replication solution:
Disk Library Replication solution can be temporarily disabled/re-enabled using
one of the following methods:
Using the nSuspendSDR registry key, in
the source machine.
To disable, create the
nSuspendSDR
registry key and set its Value to "1".
To re-enable, set the value of the
nSuspendSDR
registry key to "0" or remove the key.
Disable any job schedules created for the Disk Library Replication
solution.
Uninstall/Deconfigure the Disk Library Replication solution:
Stop (abort) replication activities; create the
nSuspendSDR
registry key (if it does not already exist) and set its Value to "1".
Delete the Replication Pairs and Replication Sets that were automatically
created when the Disk Libraries on Replicated Disks were created.
Delete any job schedules created for the Disk Library Replication
solution.
Deconfigure the Disk Libraries on Replicated Disks that were configured
on the source (remote office) and on the destination (centralized data center) MediaAgents. For instructions, see
Deconfigure Libraries; for overview information, see
Deconfiguring Libraries
and Drives.
To leave the CDR software installed and use it
to perform data replication, deselect the Disk Library Replication
option in the Replication Set (Advanced
tab) and select Continuous Replication for data replication type in
the Replication Set (General
tab). Cycle the Replication Service (CVRepSvc) on both the source
and destination computers, and skip the next step. For more
information about Services, see
Services.
Uninstall ContinuousDataReplicator (CDR) software from both the source (remote
office) and destination (centralized data center) MediaAgent computers. For
more information, see
Uninstalling ContinuousDataReplicator.
Use the following method to recover data that was backed up from a remote
office to a centralized data center.
Browse Data from the source
client in the usual manner, but select the centralized
MediaAgent from the Use MediaAgent list in the Browse Options window.
Then Restore Backup Data
to the original client at the remote office, or to a location of your choosing.
This method might be best suited to cases where data is being recovered to a
single computer, as opposed to many computers.
Review the following recommendations when deploying the Disk Library
Replication
solution:
It is strongly recommended that you employ
Deduplication
and
Replication
Compression as part of this solution, as the benefits in reducing the size
of data and speeding throughput across the network are significant.
When this solution will involve data being transmitted across non-secure
networks
Replication
Encryption is recommended to ensure data security.
When Replication Compression is enabled, do not also enable Data Compression
on the MediaAgent.
When Replication Encryption is enabled, do not also enable Data Encryption
on the MediaAgent.
While it is possible to change the read-write access for mount paths associated
with replicated disks, this should never be done for the Disk Libraries
on Replicated Disks used for this solution.
Review the following to gain a better understanding of how this solution operates:
Replication Pairs will display a state of "Stopped" in the CommCell Console
when not actively moving data. This is because the Pair will activate at the
interval you specified in the Media Management Configuration (Service Configuration)
Control Panel (or registry key
SDRPairStartIntervalMins), replicate data transferring any new or changed data, then
enter the "Stopped" state until the interval completes again.
The software automatically creates filters to exclude the area of disk where
the deduplication database is active on the source MediaAgent, so that data
from this area is never replicated to the destination MediaAgent. In addition,
filters are created to exclude temporary files from replication (/**/*.tmp
in UNIX and *.tmp in Windows.)
The option to automatically delete orphan files is specified when the Replication
Set is created by the software; for more information on this subject, see
Orphan Files.
Locked files will not be replicated; once write activity has ended for a
particular file, and it is no longer locked, it will be replicated to the
destination at the next update interval. Any data in the process of being
backed up to the source MediaAgent in the remote office will not be
replicated to the centralized MediaAgent. This means that replicated data
can only be restored successfully if the backup that they were a part of had
completed before the most recent replication started. Any backups that
completed before the start time of the latest replication as shown in the Data
Replication Monitor will be restorable.
Most of the features of ContinuousDataReplicator are not functional when
it is deployed for this solution.
The data from a source (remote office) MediaAgent cannot be replicated to
multiple destinations (commonly referred to as "fan-out") using this solution.
If you are using Auxiliary Copy to read data from the destination, then deferred copy settings
must be enabled for the Auxiliary Copy, for the number of days required for
the replication to be complete. See
Auxiliary Copy with Deferred Copies
for details.
The following products and features mentioned in this solution require an available
Product License or
Feature License in the CommServe:
MediaAgent
ContinuousDataReplicator (CDR)
Deduplication
Disk Libraries
Data Encryption
Review general license requirements included in
License Administration. Also,
View All Licenses provides
step-by-step instructions on how to view the license information.
A
typical Disk Library Replication solution is shown in the illustration.