Snapshots of applications running on a file system might cause the Snapshot copy to have inconsistent data unless measures are taken (such as, quiescing the application prior to taking the Snapshot copy) to ensure that the data on disk is logically consistent before you take the Snapshot copy.
To take a Snapshot copy of these types of applications, ensure that the files are closed and cannot be modified. The application is quiesced, or taken offline, so that the file system caches are committed before the Snapshot copy is taken. The Snapshot copy takes less than one second to complete, after which the application can resume normal operation.
If the application requires a lot of time to quiesce, it might be unavailable for some amount of time. To avoid this scenario, some applications have a built-in hot backup mode. This allows a Snapshot copy or a backup to occur while the application operates in a degraded mode, with limited performance.
Data ONTAP cannot take Snapshot copies of applications that have the ability to work with raw device partitions. It is recommended that you use specialized modules from a backup software vendor tailored for such applications.
To back up raw partitions, it is best to use hot backup mode for the duration of the backup operation. For more information about backup and recovery of databases using NetApp SAN configurations, see the appropriate technical report for the database at NOW.