Considerations before using SnapRestore

You must take into account certain considerations before deciding whether to use SnapRestore to revert a file or volume.

• If the volume that you need to restore is a root volume, it is easier to copy the files from a Snapshot copy or restore the files from tape than to use SnapRestore.

  This enables you to avoid rebooting. However, if you need to restore only a corrupted file on a root volume, a reboot is not necessary.

• If you revert the entire root volume, the system reboots with configuration files that were in effect when the Snapshot copy was taken.
• If the amount of data to be recovered is large, SnapRestore is the preferred method, because it takes a long time to copy large amounts of data from a Snapshot copy or to restore from tape.
• If a file to be recovered needs more space than the amount of free space in the active file system, you cannot restore the file by copying from the Snapshot copy to the active file system.

  For example, if a 10-GB file is corrupted and only 5 GB of free space exists in the active file system, you cannot copy the file from a Snapshot copy to recover the file. However, SnapRestore can quickly recover the file in these conditions. You do not have to spend time making the additional space available in the active file system.

• If you revert a FlexVol volume using SnapRestore, the size of the volume remains unchanged after the reversion.

  However, the volume that is being reverted assumes the size of the volume in the Snapshot copy if the following conditions are met:

  • The volume that is being reverted is contained in a 64-bit aggregate.
  • The size of the volume that is being reverted is greater than 16 TB.
  • The Snapshot copy that the volume is being reverted to was contained in a 32-bit aggregate.