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Data protection

Updated: April 2, 2014

Applies To: System Center 2012 R2 Data Protection Manager, System Center 2012 SP1 - Data Protection Manager, System Center Data Protection Manager 2010

System Center 2012 – Data Protection Manager (DPM) protects Microsoft servers, client computers, and application workloads, including Exchange, SharePoint, Hyper-V, and SQL Server. For a full list of the applications that are supported by DPM, and data that can be protected and recovered, see Support Matrix for DPM Protection. Each computer or server protected by DPM will have the DPM Protection Agent installed on it.

DPM gathers protected computers and servers into protection groups. You apply the following settings to these protection groups

  • Protection group types—You can specify whether a protection group includes client computers or servers.

  • Protection methods—You can configure short-term and long-term protection and settings associated with each.

  • Disk allocation settings—Specify how much disk space is allocated for replicas (for disk-based backup)

  • Replica creation—Before DPM can start protecting the data sources in a protection group, an initial replica of the data must be created. After a replica is created for each protected volume, changes to the protected data are transferred to DPM incrementally through synchronization, according to a set schedule.

  • Consistency check options—Specify whether you want to run a consistency check automatically or at a scheduled time.

  • Windows Azure Backup—If you’ve selected to do short-term backup to Windows Azure in addition to disk you configure the backup settings.

Protection group types

In DPM you can configure two basic types of protection groups—those that contain client computers and those that contain servers (this includes any computers running Windows server operating systems or server application workloads). The workflows for these two types of protection groups are different.

  • Client protection groups— For client protection groups you select the folders that you want to protect or exclude from protection. You can also select to allow users to use the self-service option to specify the folders they want to back up, with the exception of any folders you specifically exclude. In addition you can specify short-term and long-term options for data backup. You allocate how much disk space can be used for replica storage for the group. Since client computers are intermittently offline, you can configure protection for client computers without them needing to be online. Client computers poll the DPM server at 15 minute intervals and obtain the backup schedule specified for the protection group. The client computer starts the backup in accordance with the schedule. Additionally, if self-service is configured for the protection group, the user select a folder of their own that they want to protect and backup at any time using the DPM Client application running on the user computer.

  • Server protection group—For server protection groups that include file and workload servers, you select the servers that belong to the group, and what you want to protect on that server, including shares, volumes, application-specific data, and system protection (bare-metal recovery and System State). You specify short-term and long-term backup options, synchronization frequency, recovery point settings, and express full backup times.

Protection methods

You can set up short-term and long-term backups with protection settings.

Short-term protection

Short-term backup can be performed to disk, to disk and Windows Azure, or to tape. You can’t use short-term backup to tape for client protection groups, or for workload data. Short-term tape backup can’t be used for bare metal recovery or for storing Exchange DAG mailbox workload data.

Long-term protection

Only tape is supported for long-term backup. Note that if you’re using tape for long-term protection you can select to compress and encrypt the data. You can’t do both. Note that encrypted data might result in taking up more space than unencrypted data. Data encryption will require a certificate for authentication. Long-term protection can be configured in two modes. Disk-to-tape (D2T) mode backups up data directly from the protected resource to tape. Disk-to-disk-to-tape mode backups from data from the protected resource to disk, and then to tape. Client computer data, bare metal recovery data, and Exchange DAG mailboxes can’t be protected using D2T mode.

Retention settings

Retention settings specify how long data will be available for recovery:

  • Short-term to disk: 1-64 days

  • Short-term to Windows Azure: 120 days at one backup per day. If you do two backups per day (the maximum allowed) maximum retention will be 60 days.

  • Short-term to tape: Up to 12 weeks

  • Long-term to tape: Up to 99 years

Synchronization frequency

Synchronization frequency specifies often the data you want to protect will be synchronized with the DPM replica. You can select from 15 minutes to 24 hours, or you can select to synchronize only before a recovery point is created (in accordance with your recovery point settings). The default setting is 15 minutes which means your DPM server version of the data won’t be more than 15 minutes behind the version on the protected computer. DPM uses a couple of types of synchronization:

  • Incremental synchronization (also referred to as synchronization) transfers changes to data from the protected computer to the DPM server and then applies the changes to the replica. When you create a protection group, you specify a synchronization schedule or accept the default schedule. In general, you can rely on incremental synchronization to keep a replica consistent with its data sources. This method is faster and more efficient than performing a consistency check because it uses the DPM filter to identify the changed blocks. For application data such as Exchange and SQL Server database that support incremental backup, each successful synchronization is a recovery point, and will truncate database logs.

  • Synchronization with consistency check (also referred to as a consistency check) transfers the data changes from the protected computer to the DPM server but also performs block-by-block verification to ensure that all the data on the replica is consistent with the protected data. This process is slower than synchronization because all the data on the replica is compared rather than simply applying the data changes to the replica.

  • Express full backup— An express full backup is a type of synchronization that transfers and synchronizes only a snapshot of all blocks that have changed, either since the initial replication or since the last express full backup. It’s faster than running a full backup. Recovering the data from an Express Full Backup produces the same result as recovering data using a full backup. The express full backup uses DPM filter technology to identify the changed blocked instead of requiring DPM to read all the data or use checksums. This significantly reduces performance load. Express full backups are considered copy-only full backups and do not result in log truncations for applications that support incremental backups.

Recovery points

A recovery point (snapshot) is a point-in-time copy of a replica stored on the DPM server. DPM creates recovery points of each replica in a protection group according to recovery point settings. You can access the recovery points to recover previous versions of files in the event of data loss or corruption. You can recover data from recovery points, and you can configure end-user recovery so that users can recover their own data from recovery points.

Recovery point schedules for short-term disk backup

Recovery points are created from synchronized replicas, as follows:

  • If you set the Synchronization frequency option to Just before a recovery point, each synchronization will result in a recovery point in accordance with the Express full backup time.

  • If the Synchronization frequency option isn’t set to Just before a recovery point, then synchronizations occur at the interval specified, and recovery points are created in accordance with the schedule. The default schedule creates recovery points at 8:00 A.M., 12:00 P.M. and 6:00 P.M. daily. You can modify both the times and the specific days. You cannot specify different times for different days. For example, you can schedule recovery points for 2:00 A.M. and 2:00 P.M. on weekdays only; however, you cannot schedule recovery points for 2:00 A.M. on weekdays and at 12:00 P.M. on weekends.

  • In addition you can manually create a recovery point from the most recent file synchronization.

For file recovery points you can use the default settings or select the days and times for which you want recovery points created. Application recovery points are used for SQL Server and Exchange, and the synchronization frequency determines the recovery point schedule. Note the following:

  • For application data, If you set the Synchronization frequency option to Just before a recovery point, DPM performs only express full backup to synchronize the replica according to the recovery point schedule. For SQL Server databases, setting this option results in copy-only backups which will prevent SQL Server logs from being truncated. DPM copy-only backups of the SQL Server databases allows other SQL Server backup application or methods to perform incremental backups which will result in log truncation.

  • For applications that support incremental backups, the default schedule results in recovery points for each synchronization (every 15 minutes) and for the express full backup at 8:00 P.M. daily. For applications that do not support incremental backups, the default schedule results in a recovery point for the express full backup at 8:00 P.M. daily.

  • For protection groups protecting file data you can hold up to 64 recovery points on disk. (This is a VSS limitation for client accessible shadow copies). So for example, if you schedule one recovery point per day (or 7 per week) you can retain 64 recovery points for a maximum of 9 weeks. If you create one recovery point a week (which is 7 * 64 recovery points) you have a maximum retention range of 448 days.

  • For SQL Server and Exchange you can have up to 512 recovery points. Note that DPM reserves 64 recovery points, so you can actually only select up to 448 recovery points. This is because DPM assumes that file protection could use the same volume as the protected application, so the VSS shadow copies apply to the same volume. Therefore, 448 + 64 = 512 (which is the VSS shadow copy maximum per volume).

  • Transaction log backups, which DPM uses for incremental synchronization of application data, cannot be performed for a SQL Server database that is read-only, configured for log shipping, or configured to use the Simple Recovery Model. For those SQL Server databases, recovery points correspond to each express full backup.

Recovery point schedules for short-term tape backup

If you’re doing short-term backup to tape, you configure Only full backup, or Full and incremental backups, instead of recovery points. If you schedule daily backups you can use the full or full and incremental options. If you schedule weekly or bi-weekly backs you can only use the full backup option.

Recovery points for long-term tape backup

Recovery point schedules for long-term tape backup will depend on the backup frequency and retention range, and are summarized in the following table.

 

Recovery Point Schedule Retention time and recovery point schedule (full backup)

Daily

1-4 weeks

  • Daily

1-11 months

  • Daily x 4 weeks

  • Monthly after first 4 weeks

1-99 years

  • Daily x 4 weeks

  • Monthly after first 4 weeks, until 12th month

  • Yearly after first 11 months

Weekly

1-4 weeks

  • Weekly

1-11 months

  • Weekly x 4 weeks

  • Monthly after first 4 weeks

1-99 years

  • Weekly x 4 weeks

  • Monthly after first 4 weeks, until 12th month

  • Yearly after first 11 months

B-weekly

1-11 months

  • Every 2 weeks x 4 weeks

  • Monthly after first 4 weeks

1-99 years

  • Every 2 weeks x 4 weeks

  • Monthly after first 4 weeks, after 12th month

  • Yearly after first 11 months

Monthly

1-11 months

  • Monthly

1-99 years

  • Monthly until 12th month

  • Yearly after first 11 months

Quarterly

1-99 years

  • Every 3 months until 12th month

  • Yearly after first 11 months

Half-yearly

1-99 years

  • Every 6 months until 12th month

  • Yearly after first 11 months

Annually

Yearly

Disk allocation settings

When you create a new protection group, DPM allocates disk space for the protection group in the storage pool. The DPM estimation will take into account the retention range, work load type and the size of the protected data. This disk space will include space for the replica and recovery point volumes. In addition to recommending the disk space allocation, DPM will verify that the protected computer contains sufficient space for the change journal.

When you configure disk allocation settings you can select to automatically grow the volumes. With this setting enabled DPM will try to automatically grown the volume by 10 GB or 25% (whichever is larger) if required. If you don’t select this setting (or automatic growth doesn’t work) DPM issues an alert to let you know there’s an issue. You’ll need to take action to resolve this active alert by manually growing the affected volume using the Modify Disk Allocation Wizard. And then resume backups to inactivate the alert.

You can configure disk allocation manually. For example if you’re only protecting a subset of data on a protected volume you can specify the size of the protected data as a basis for DPM to perform the estimation. You can also click calculate and DPM will enumerate the subset of protected data selected and adjust the replica size automatically.

Replica creation

You can create the initial replica using a couple of methods:

  • Over the network— You can transfer the replica directly over the network. Replicating the data over the network requires no intervention, but it can take several hours, depending on network bandwidth and the data size. To minimize the impact on network bandwidth, you can schedule replication for a time when network traffic is low. Note that you can use the network bandwidth usage throttling settings in DPM to reduce network performance impact.

  • Using removable media—You can manually create the replica using a tape backup or other removable storage medium. This method does not affect network bandwidth, and it can save time if you are transferring large amounts of data. However, you must manually copy the data to the DPM server and then manually synchronize the replica with a consistency check before scheduled synchronization and recovery point jobs can succeed.

Consistency check options

You can select to run a consistency check between the protected data and its replica. You can run scheduled consistency check or a one-time manual check. You can schedule a consistency check as a daily task, or schedule to run only when an inconsistency is detected. schedule. You can also set a timeout for the maximum duration of a check. Note the following:

  • We recommend you use the option to run a consistency check when an inconsistency is detected for workloads lesser than 1-terabyte, or for workloads within a single data center.

  • A scheduled daily consistency check will only run if inconsistencies are detected during synchronization. We recommend you to use this option for large workloads or for data that is backed up over WAN.

  • The performance of the protected computer and the DPM server will be affected while a consistency check is running. It is best to schedule consistency checks and perform one-time consistency checks during off-peak hours.

  • When a consistency check is performed and inconsistencies between the protected volume and the replica volume are found, DPM makes the replica consistent.

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For additional resources, see Information and Support for System Center 2012.

Tip: Use this query to find online documentation in the TechNet Library for System Center 2012. For instructions and examples, see Search the System Center 2012 Documentation Library.
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