Home > Storage > Data Storage Essentials > AppSync > Dell AppSync: Integration with Oracle Database Server > Understanding the Oracle layout to identify objects for copy
When copying a file system that is on a logical volume, AppSync copies, mounts, and restores by volume group.
Copies that are based on volume groups have the following characteristics:
For example, assume there are two file systems on two different devices, and both devices reside in a single volume group. It is impossible to restore one of the file systems because all file systems belonging to the same volume group are restored. The process begins with all the logical volumes being exported from the production data server. After the restore, all the volumes are imported to the production data.
In this example, the datafiles, including the control files and redo logs, are part of one volume group (VG1), and the archive logs and optionally the FRA files, make up another volume group (VG2). If you choose to copy only the datafiles, the redo logs are automatically copied because they are part of the same volume group. Similarly, while copying the archive logs, for example when using the hot backup option, the archive logs and FRA, or other files in VG2, are managed together.
Note: If other file systems that are not part of the Oracle database environment share the same volume group as the datafiles or archive logs, they become affected entities. This instance can cause mount and restore issues because AppSync is not aware of the other file systems or environments. For AppSync versions 3.7 and later, these affected entities are detected, and a warning appears in the UI.
If you choose to restore only the datafiles, the redo logs are also restored because they are part of the copy. Similarly, when you restore the archive logs, all items in that VG must be restored together.
AppSync versions 3.7 and later provide an option to select archive log destinations for copies created using hot backup. Earlier AppSync versions can protect all the archive log destinations. This scenario could result in storage overhead because all destinations contain copies of the same archive log files. This option is useful when you want to reduce the storage footprint of or for an Oracle copy.