Backup / Restore of NAS (Linux DS-Client)
Creation Date: December 02, 2011
Revision Date: May 01, 2013
Product: DS‑Client (Linux)
Summary
This article describes the backup and restore process for NAS (Network Attached Storage) devices using the “NAS, UNIX-SSH, NFS, Local File System” backup set type.
To back up/restore the NAS device, DS-Client utilizes a dedicated API from the NAS vendor. DS-Client uses the API for creating a volume based snapshot on the NAS device for the data selected in the backup set. After creating a snapshot, DS-Client temporarily mounts a NAS share and backs up the data from the snapshot. When the backup is finished, DS-Client unmounts the NAS share and deletes the snapshot.
NOTE: CIFS shares or volumes with NTFS / Mixed security type are not supported.
NOTE: NAS backup is only supported on Linux DS-Client (not on Mac DS-Client).
See also
Creating a NAS backup set
1. Open DS-Client New Backup Set Wizard, select NAS, UNIX-SSH, NFS, Local File System and click Next.
2. Select NAS and enter the NAS IP address or DNS name in the Path field (e.g. “NAS\10.10.20.33”). Select Ask for credentials if the current DS-Client user has no data access rights on the NAS device or if you want to use a different user. Click Next.
If the Ask for credentials option is selected, the Ask for credentials windows appears.
3. Provide a valid user name and password and click OK.
By default, the option Ask for NAS API credentials is selected, and you are prompted to enter the NAS API connection credentials.
4. Select the NAS type and the API access protocol. Specify the port for the API connection, API user credentials and a mount point to be used for mounting the NAS share during the backup. Use an existing mount point or create a new one for the backup purpose. Click OK.
NOTE: Make sure the specified User has rights to execute the API commands on the NAS device. The user should be a member of the Administrators group.
5. Browse the NAS shares and add data to the Selected Items for Backup list and click Next.
6. Follow the next steps as you would for the online backup set type until the Specify backup set options screen appears.
7. Select the desired behavior for the Continue backup on snapshot failure option:
If this option is selected (default), then in case of a snapshot failure, DS-Client will try to access the data selected in the backup set directly by skipping the snapshot functionality.
If this option is not selected, then in case of a snapshot failure, DS-Client will stop the backup process.
8. Specify all the required options and create the backup set as you would with an online File system backup set.
NetApp configuration requirement
For NetApp NAS volumes, there is a volume configuration option that enables access to the snapshot file for NFS when browsing the NetApp volumes. This must be selected, otherwise DS-Client cannot access the snapshot.
NetApp Clusters
If you are backing up a NetApp cluster, make sure to select NAS type in the Ask for NAS API credentials screen. This will allow DS-Client to interact with the NAS API correctly.
Snapdiff API
Linux DS-Client has the Use Snapdiff API option for (NetApp) NAS backup sets. This will appear if DS-System is using NetApp storage, and is configured to support the NetApp Snapdiff. If selected, DS-Client will attempt to use the NetApp Snapdiff API to avoid re-scanning the whole NAS volume during an incremental backup. Snapdiff compares the current snapshot with the last snapshot of the target NAS volume and generates the list of new and changed files from that comparison. This can provide significant speed improvements to the backup process, especially on large volumes.
The following limitations exist. In all cases where Snapdiff fails, DS-Client will attempt a full scan of the NAS volume.
NOTE: A previous snapshot should exist so that the Snapdiff API can function.
• Snapdiff does not work on the first (baseline) backup.
• Snapdiff does not work if the current snapshot fails.
• Snapdiff does not work if any of the backup set’s backup items have been changed (since the previous backup).