Scheduling a new snapshot set

Before you run the VSS Snapshot Scheduler Wizard to schedule a snapshot set for a database, you must prepare a snapshot mirror for each of the volumes in the database.

See Preparing the snapshot mirrors.

You can then use the VSS Snapshot Scheduler Wizard to schedule the initial snapshot set and to set up the schedule for keeping it refreshed.

When the scheduled snapshots occur, the snapshot mirrors are detached from the original volumes, creating separate on-host snapshot volumes as well as an XML file to store the SQL and snapshot volume metadata. The scheduled process integrates with VSS to quiesce the databases and then simultaneously snapshot the volumes in the database. This snapshot is done while the databases are online and without disrupting the database operations.

To schedule a snapshot for a selected component

  1. From the VEA console, navigate to the system where the production volumes and snapshot mirrors are located.

  2. Expand the system node, the Storage Agent node, and the Applications Node. If the SQL node is not shown, start the SQL Server VSS Writer service and then select the Storage Agent node and refresh the VEA display (Actions > Refresh).
  3. Expand the SQL node.
  4. Right-click the instance, and click Schedule VSS Snapshot.
  5. In the Welcome panel, review the information and click Next.
  6. Specify the snapshot set parameters as follows and then click Next:

    Select component for snapshot operation

    Select the database for the snapshot set.

    Directory

    The XML file is stored by default in the directory shown on the screen.

    In a clustered server environment, the XML file must be saved on shared storage to be available from all nodes in the cluster.

    Note:

    The XML file for the snapshot must be stored separately from the volumes that are included in the snapshots, otherwise a restore will fail.

    There are two ways to change the XML file location.

    First, edit the directory path in the Directory field for this wizard screen. Second, change the XML file location. Use a text editor to create a text file named redirect.txt. This text file should contain a single text line specifying the Universal Naming Convention (UNC) path to the location of the XML file, for example, \\ServerName\SharedFolderName. Save the redirect.txt file in the default directory C:\Program Files\Veritas\Veritas Volume Manager\VSSXML.

    If the product is installed on the D drive, then the path will be the same as above, but on the D drive

    Note:

    You must not use the volume name or volume path in the redirect.txt file that is involved in the snapshot. If the volume name or path for the snapshot is used, then a restore will fail.

    Snapshot set

    Enter a name for the snapshot set, for example, billing or accept the default name. The wizard generates a default snapshot set name that includes the term "SnapshotSet", component name, date, and time.

    The wizard creates the snapshot set metadata XML file with this name.

    Select snapshot type

    Select the snapshot type.

    You can specify that snapshots be created as either a Full backup or Copy backup type. Either type can be used to restore a database. However, if you want to replay logs in SQL Server as part of restoring a database, a Full backup needs to have been created earlier. When replaying logs, you can replay from the time of the last Full backup. A Copy backup does not affect this sequence of log replay and therefore is often used as an "out of band" copy for purposes such as testing or data mining.

  7. In the Change Attributes panel, optionally change the attributes for the snapshot volumes and click Next:

    Volume Name

    Displays the name of the volume.

    Snapshot Volume Label

    Displays the read-only label for the snapshot volume.

    Drive Letter

    Optionally, click a drive letter and select a new choice from the drop-down menu.

    The drive letters specified may not be available when the snapshot is taken. When this occurs, the snapshot operation is performed, but no drive letters are assigned.

    Plex

    Optionally, click a plex and select a new choice from the drop-down menu.

  8. Optionally, in the Synchronized Snapshot panel (Volume Replicator only), select the secondary hosts for which you want to create synchronized snapshots. Either double-click on the host name or click the Add option to move the host into the Selected Secondary Hosts pane. To select all the available hosts, click the Add All option. The VSS wizard creates synchronized snapshots on all the selected secondary hosts.

    This panel is displayed only in an environment using Volume Replicator. Otherwise, you will be directly taken to the Schedule Information panel.

    See Volume Replicator Administrator's Guide.

  9. In the Schedule Information panel, on the General Options tab, specify the following:

    Name of this schedule

    Enter a unique name for the snapshot set schedule.

    This name identifies the snapshot schedule if you later want to view information about the snapshot status. A default name consists of the VSS writer name, the component name and a numbered suffix that increments with each schedule.

    Description of this schedule

    Optionally, enter a description to help you identify the schedule when you view information about the snapshot status.

    Start Time

    The time of the day to begin taking snapshots.

    End Time

    The time of day to end taking snapshots.

    If a snapshot is in progress it is completed but a new one is not started after the end time.

    Schedule takes effect on

    The date on which the specified schedule takes effect. The default is the current date.

    Restart task every

    The interval between snapshots, in minutes.

    For example, if the interval is 360 minutes and you schedule a snapshot start time of 12 P.M. and an end time of 7 P.M, the snapshot occurs twice. If no interval is specified the snapshot occurs once.

    Every

    Enable the Every option to have the snapshot schedule continue to occur. Otherwise the schedule applies only for one day.

    Specify the number of days before restarting the snapshot schedule.

    For example, 1 day would mean the schedule takes effect daily, 2 days would mean every other day.

    Start On

    If you enable the Every option, specify the starting date.

    Pre Command

    Optionally, specify the full path of a command script to run before the scheduled snapshot occurs.

    Post Command

    Optionally, specify the full path of a command script to run after the snapshot is complete.

  10. To specify run days for the schedule, make selections on the following tabs:

    Days of Week

    Select one or more days on one or more weeks of the month.

    You can click a button at the top of the column to select the entire column or a button to the left of a row to select the entire row. For example, clicking First schedules the snapshots to occur on the first occurrence of all the week days for the month.

    Days of Month

    Select one or more days of the month. You can also check the Last Day checkbox to schedule the snapshot for the last day of each month.

    Specific Dates

    Select one or more specific dates to include in or to exclude from the schedule.

    Excluding a date takes precedence over days scheduled on the other tabs. For example, if you schedule every Monday on the Days of Week tab, and you exclude Monday October 9 on the Specific Dates tab, the snapshots are not taken on October 9.

    If two schedules overlap for the same snapshot set, only one snapshot is taken. For example, if you select every Thursday plus the last day of the month, and the last day of the month occurs on Thursday, only one snapshot is taken on Thursday.

  11. Click Next.
  12. Review the snapshot set and schedule details and click Finish.