V11 SP8

FAQ - NAS iDataAgent

Table of Contents


What are two-way restores?

A two-way restore consists of restoring the data to a file server from a locally attached (or SAN-connected) library.

The following restore methods are supported:

  • Restoring to the same location on the file server from where the data was backed up.
  • Restoring to a different volume or folder on the same file server.

What are three-way restores?

A three-way restore consists of restoring the data to a client that is not directly attached to the backup location. A three-way restore enables more than one file server to share a library, allowing data to be restored to a file server that may not have a locally attached library.

For more information, see Restores to Windows or UNIX Clients.

Can I browse for content on all subclients?

No. You can browse for subclient content only on NetApp 7-Mode, NetApp C-Mode, and Isilon clients. For vendor-specific information about adding subclient content, see Guidelines for Adding Subclient Content.

Can I restore block based backups to multiple ONTAP releases?

No. You can restore block based backup images up to one or two major ONTAP releases. It is highly recommended that you consult the NetApp documentation for limitation on block based backup restores.

Can I perform block based backups on file servers with versions prior to ONTAP 8.0?

It is required that you get an approval from NetApp in order to perform a block based backup on a file server running an ONTAP version prior to 8.0.

Can I enable the Image Backup Set option on a SnapVault copy?

Yes, you can enable the Image Backup Set option (for SnapMirror to Tape) on a backup set containing the SnapVault copy. However, for 7-Mode file servers the image backup of the SnapVault copy will not exactly match the primary (source) volume. For example, the non-qtree data on the primary volume will be in a qtree on the SnapVault copy; the SnapVault copy may also contain data from other primary volumes.

Do I have to restart SnapMirror to Tape backups from the beginning?

Yes. You must restart SnapMirror To Tape backups from the beginning of the job. You cannot restart SnapMirror to Tape backups from another point in the backup.

Can I use filters for SnapMirror to Tape backups?

No. Backup filters cannot be used for SnapMirror to Tape backups. If you add filters, they are ignored.

Can I perform an in-place restore of root volumes for SnapMirror to Tape backups?

No. In-place restores of SnapMirror-To-Tape backups (also referred to as Image Backups) of the root volume on a NetApp file server are not supported. While you can perform a SnapMirror to Tape backup of the root volume,  you cannot restore to it because the root volume cannot be turned offline.

Is SnapMirror to tape (SMTape) supported for Cluster-Mode?

SMTape is only supported for Cluster-Mode NetApp arrays running ONTAP 8.3 or later. The array must also belong to a Commvault version 10 CommCell updated to SP9 or later.

Can I perform a direct access restore of an Image backup?

No. The Direct Access Restore option is ignored for restores from image backups. If selected, the option does not affect the restore.

Can I use a MediaAgent-attached drive pool to restore data that was backed up using an NDMP drive pool?

No. To restore NAS data, you must use the same drive pool type that you selected during backup. For example, if an NDMP drive pool was used to perform the backup, you should also select an NDMP drive pool during restore.

Are non-Image browse operations of Celerra data supported for Direct Access Restores?

Yes. Browse operations for EMC Celerra are always non-image browse operations. Even if an image browse is performed, the restore will be a non image restore.

What are some of the operations that the MediaAgent allows me to perform?

The MediaAgent software allows you to perform the following operations with the NAS data:

  • Back up data from file servers to a library attached to a MediaAgent
  • Perform auxiliary copy operations to a library attached to a MediaAgent.
  • Perform deduplication, encryption and compression operations.
  • Use a drive pool configured to a MediaAgent as a backup destination. The MediaAgent allows that any storage policy configured to use a drive pool can be selected as a backup destination.

How do Direct Access Restores behave when restoring large data?

The nRESTORELIMIT additional setting is automatically created during installation to control the behavior of large direct access restores.

This key specifies how many files/directory names can be sent in a single restore request; between each request, the tape will be positioned to the start of the first tape. For example, performing a direct access restore of a tree with 24,000 files/directories would require three restore requests (using the default value of 8192 per request) to be sent to the file server.

When should I perform a Direct Access Restore?

It is hard to define when a Direct Access Restore provides better performance as each environment is different and has many variables that can affect restore efficiency. Use the following guidelines to determine if this restore operation is appropriate for your environment:

  • If the data to be restored is less than 30-40% of the backup, it is recommended to perform a direct access restore.
  • For three-way restores, as it involves more overhead processing between the library and the file server, it is recommended to perform a non-direct access restore even if the percentage of the backup being restored is under 30%.

If you are not using direct access restores, restore performance is still optimized where possible. For instance, if the most recent copy of the data that you want to restore was backed up by an incremental or differential backup, the restore only reads the archive file from that differential or incremental backup, instead of reading the archive files back to the last full backup.

Can I backup data to a local tape drive for a NetApp vFiler?

No. You can backup data on a NetApp vFiler by adding the vFiler as a NAS client.

What is Tape Silvering?

Tape silvering is the process of shipping a physical copy of the source data to a destination site. This is useful for large file systems as it saves time and resources and also avoids transferring the file system over the network. Refer to the EMC Celerra documentation for more information.

Can I perform the block based backup for an on-demand backup set?

You can perform the block backup for an On-Demand backup set. You must configure an On-Demand Backup Set for block backup. However, once you configure the On-Demand Backup Set for block backup, you cannot change the configuration and perform the regular backup for the On-Demand Backup Set.

Can I perform incremental or differential backup for a block based backup set?

Incremental and differential backups are supported on image backup sets with file servers running ONTAP 8.1.1 or higher. If you have an ONTAP version lower than 8.1.1, then only full backups are supported. 

  • To run incremental or differential backups for NetApp image backup sets (SMTape), the first full backup and all subsequent backups must be performed from a snapshot. The snapshot used for the full backup must be available on the volume to be able to run a differential backup. Similarly, the snapshot used for the previous backup must be available on a volume to be able to run an incremental backup. Therefore, the snapshot retention must be planned accordingly to allow the image tape backups to be successful.
  • When moving a snapshot to tape (backup copy), the user is not required to select the snapshot to use for the operation. When running a traditional SMTape backup, however, the snapshot name must be provided by the user in the Snapshot to Back Up field in the backup advanced NAS options (see the Snapshots to Back Up procedure in IntelliSnap - Advanced Backup - NAS Agent).

Can I perform a File System Restore on files with long path names?

Files that have a path length greater than 1024 characters are not indexed during the backup and do not appear during browse operations. To restore these files, you must reduce the length of the restore path by browsing to a directory that is at a higher directory level (parent directory) in the file system.

Are backups and restores LAN-free?

Backups and restores using a library attached to a file server will be LAN-free. However, backup and restore operations using using a library attached to a MediaAgent will not be LAN-free.

When does a non-full backup automatically get converted to a full backup?

A non-full backup is automatically converted to a full backup in the following situations:
  • First backup of the subclient.
  • Promote a secondary storage policy copy that is not synchronized with a primary copy (for all the subclients of a storage policy).
  • If you switch from a IntelliSnap backup to a traditional backup or vice versa.
  • CommCell Migration operation.

Is NDMP backup supported by NetApp Infinite Volume?

No. Tape backup and backup copy will not work on Infinite Volume.

Is NDMP backup supported by NetApp Flexgroup Volume?

No. Tape backups and snap backups will not work on Flexgroup Volume.

Why can't I run incremental backups anymore?

Most file servers have a limit to the number of incremental backups that you can perform. You can configure the software to automatically start a new differential backup when the maximum number of incremental backups has been reached using the sNDMPAutoStartDiffOnNoMoreIncremental additional setting. You must configure this additional setting on the CommServe client and enter the value as Yes.

For more information about creating an additional setting, see Adding or Modifying Additional Settings from the CommCell Console.

Restores to Windows and UNIX Clients

Can I restore data from a file server to a Windows or UNIX computer?

Yes, you can restore NAS data to a Windows or UNIX client computer from the following file servers:

  • Hitachi NAS (BlueArc)
  • NetApp
  • EMC Celerra, Unity, VNX, and VNXe
  • Isilon

In order to restore data to a Windows or UNIX client, ensure that the appropriate File System agent is installed on the computer where you want the data to be restored.

This type of restore is also known as a cross-platform restore, where the data is restored to a computer with a different operating system. For example, data from a NetApp file server running ONTAP can be restored to a Windows computer. Note that restore to a UNC path or a mapped drive (Windows) is not supported. Restore to an NFS-mounted file system (UNIX) is supported if you have the necessary permissions.

Are there limitations for restoring NAS data to a Windows or UNIX computer?

Yes. The following are general limitations for restoring NAS data to a Windows or UNIX client:

  • Data that was deduplicated using the Celerra file system cannot be restored.
  • Offline files (stubs) cannot be restored.
  • Restores from NetApp SnapMirror to Tape (SMtape) backups are not supported.
  • Restores from Celerra volume based backup (VBB) are not supported.
  • Files and directories that contain Access Control Lists (ACLs) or permissions are restored, but the ACLs are not restored.
  • Links within files may not be restored.
  • Empty folders are not restored.

The following are limitations for restoring NAS data to Windows clients:

  • File and directory names with case differences will be treated like files and directories of the same name. This may cause one file/directory to overwrite another during the restore.
  • Files and directories with names containing Unix-specific characters may have those characters replaced with a "_" character or have some other form of modification in the restored file/directory name.
  • Windows allows 1024 characters for filenames, including the path. A filename, including the path, with more than 1024 characters will not be restored to the Windows computer.
  • Links within files may not be restored.

The following are limitations for restoring NAS data to UNIX clients:

  • Links within files may not be restored.

Storage Policy

Which storage policy can be assigned to a subclient?

For NAS subclients, you can select a Storage Policy associated with either of the following:

  • drives configured on a MediaAgent
  • drives configured on a NAS file server

If the drives are configured on a MediaAgent, you must install the following on the MediaAgent:

  • File System iDataAgent

Can I use a library that is attached to a NAS File Server to backup data from any iDataAgent?

Yes. You can backup data from any iDataAgent to a library attached to NAS file server. Perform the following to backup data to NAS attached library.

  • Assign a storage policy with NAS attached library to the subclient.
  • Ensure that all copies from the storage policy use the NAS attached library.
  • Use the file servers provided by the same vendor for the A NAS client and the file server attached to the library.
  • If the primary copy is configured to use additional data paths, ensure that the drive pools in all the data paths must point to the same type of file servers. Also, ensure that the drive pools of all the secondary copies, point to the same type of file servers.
  • If a storage policy is utilizing a drive pool directly attached to a NAS file server, then ensure that the MediaAgent in the data path is connected to the file server.

I have a tape written by a file server to a NAS attached tape drive. Is it possible to read the data on the tape using a MediaAgent?

No. The tape cannot be migrated to a library attached to a MediaAgent and you cannot restore the data using the MediaAgent.

Auxiliary Copy

Can perform an auxiliary copy for a Hitachi NAS (BlueArc) client?

Yes. You can perform auxiliary copy operation for a Hitachi NAS (BlueArc) OS 4.1 NAS client or for any previous versions of Hitachi NAS (BlueArc) OS. However, before performing auxiliary copy ensure that the data was not backed up to a drive pool attached to a NAS client.

Can I encrypt the data while performing the auxiliary copy for a MediaAgent?

Yes.Auxiliary copy encryption is supported for MediAgent data; however, it is not supported for File Server data.