IntelliSnap - Frequently Asked Questions - DB2 MultiNode

Can I perform an IntelliSnap backup for log files?

During an IntelliSnap backup, log files are not moved to the snapshot copy even if you select Backup Log Files option in the subclient where the backup operation is being performed. Log files always use the traditional backup method, not the IntelliSnap backup. Even if the data and logs are on the same subclient, the IntelliSnap backup for data and the traditional log backup will run as two separate jobs.

Can I restore tablespaces from IntelliSnap backups?

No. You cannot perform a tablespace restore (partial restore) from DB2 IntelliSnap backups. However, you can perform a point-in-time restore of a tablespace from a regular backup image, if the last backup image is a snap backup on a snap copy or on a backup copy. You can restore an entire DB2 database from snap backup images on any copy.

Is the symbolic or soft link path supported for IntelliSnap backup for this iDataAgent?

Yes, they are supported if you use a UNIX environment. The destination volumes referenced by Symbolic/Soft links are automatically included in the IntelliSnap backups. Soft link directory structure is supported on both NFS and SAN volume.

How does an IntelliSnap backup operation work?

When you run a IntelliSnap backup operation, the Commvault software performs the operations listed below in the following sequence of events:

Create Snapshot on the Source

This event includes the following operations:

1. Device detection based on subclient content.

   This operation gathers information from local volume managers, multipath devices and physical disks (including partitions). For example, information on UUIDs is retrieved from a local volume manager.

2. Take snapshot of detected devices

   This operation invokes the snapshot functions from the file server and creates the snapshot. Once created, Commvault records the snapshot in the CommServe database along with metadata, which includes information about local volume managers, multipaths and physical disks.

Mount Snapshot on Proxy

This event includes the following operations:

1. Map LUNs to the MediaAgent

   This operation invokes the file server functions to map clone devices to the proxy MediaAgent.

2. Recreate Storage Hierarchy

   Based on the metadata collected during device detection and snapshot creation, Commvault recreates the storage hierarchy as follows:

   • Devices are rescanned at the operating system level in order to allow the proxy to see the snapshot LUNs.

   • For each device detected on the source, Commvault checks the partitions to determine if the device is accessible or if it is a multipath device. If it is a multipath device, then the operation fails as partitions on multipath are not supported. However, if it is not a multipath device, then the software will keep parsing the device name to retrieve the partition information.

     When a partition number is detected, it is appended to the device name of the LUN. If no partition number is found, the full device name is used.

   • If required, the hierarchy of the local volume manager is recreated based on the metadata collected during device detection and snapshot creation.

   • File systems (LUNs and multipath disks) are mounted on the detected devices. Logical volumes are mounted in the case of logical volume managers.

   • Index is created and the software moves the data to the media.

What provisioning policies can I use?

Provisioning Policies are optional to use. During the creation of the secondary snapshot copy, the following Provisioning Policies are automatically created and available for selection in the CommCell Console:

• SnapProtect_RAID-DP

• SnapProtect_Dedupe

• SnapProtect_Mirror_Destination

If you need to create your own provisioning policy, ensure it is defined with the following naming convention in the DFM server:

SnapProtect_<provisioning_policy_name>

where "SnapProtect_" is the prefix required for the provisioning policy to be available in the SnapProtect software.

What happens when a vault or a mirror copy is created?

During an Auxiliary Copy job, a new dataset is created or an existing dataset is modified with new data members, as explained in the following flow of events:

1. When the IntelliSnap software assigns data to the service catalogue, a new baseline transfer may have started in the Data Fabric Manager (DFM) server.

2. The Auxiliary Copy job details display its status as the baseline transfer is in progress.

3. Once the baseline transfer is completed, the IntelliSnap software adds the snaps to the backup list, and the backup starts with the DFM.

4. If SnapMirror is the destination copy, then the IntelliSnap software sends a command to update the mirror.

   The DFM job is monitored and marked as completed/failed depending on the DFM job status.

How are snapshots copied during a backup copy operation?

The snapshots are copied to media in a sequential order. If you wish to perform an inline backup copy operation and a previously selected snapshot has not been copied to media, the current IntelliSnap backup job will complete without creating the backup copy and you will need to create an offline backup copy for the current backup.

Can I perform an IntelliSnap backup for DB2 DPF when the database is on an NFS Volume?

Yes. You can perform a IntelliSnap backup for DB2DPF when the database is on a NFS Volume. However, you will require a root access in the storage device's NFS configuration to be able to read and write on the accessible DB2 files i.e., the host on which the NFS Volume is mounted.

Consider the following while performing an IntelliSnap backup for data or databases that reside on an NFS volume:

• The export name on the storage device should be the same as the storage path on the storage device.

  For example, if the storage path of the storage device is /vol/Volume/Qtree, use /vol/Volume/Qtree as the export name and not an alias such as /ExportName.

• You can use the exports both at the root of a NetApp volume and at subdirectory levels below the root of the volume.

• Make sure that the storage device is accessible from the source and proxy machine (even if they exist in different domains) using the storage device's short name while mounting NFS exports from the storage device. Make sure to enter the storage device credentials using its short name. Do not use an IP address or the fully qualified domain name.

  For example, use a short name for the server such as server1 or server2.

What should I take into account when using Retention by Number of Jobs?

Configuring a storage policy or snapshot copy with job based retention is recommended for File System and File System like Agents, and not for Database Agents.

Review the following scenarios if you are using the retention by number of jobs configuration:

• During a browse operation, deleted files may be displayed for recovery. If the jobs containing these files are pruned by the retention criteria, the deleted files will be irrecoverable.

• You may need to manually delete jobs from deconfigured clients. These clients will continue to retain the old jobs since new jobs will not run again on them.

• When you associate a new storage policy to a subclient, it is important to perform a full backup operation in order to be retained by the new storage policy. The old storage policy will continue to retain the old jobs until you manually delete them.

What UTF setting should be used for Volume Language?

To successfully browse and restore files on a NetApp filer that contain Unicode characters, it is recommended to use the UTF-8 setting for volume language. Please consult with NetApp for implications of changing volume language.

How is the Data Fabric Manager server affected when a snap copy is deleted?

If you delete a snapshot copy, the following components in the OnCommand Unified Manager server will be affected:

• The storage services associated to the snapshot copy will be deleted.

• Datasets associated with the deleted storage service will be deleted.

  Secondary volumes/datasets are not deleted as they are stored in case you need to perform a restore operation from a deleted dataset. Secondary datasets can be removed manually, if needed.

• Any relationship associated with a dataset will be deleted within a configurable period of time defined in the OnCommand Unified Manager server.

• Base snapshot copies remain available.

Is multi instancing supported?

No. Multi Instancing is not supported for IntelliSnap backup.

Can I use Media Explorer to restore data?

No. You cannot use Media Explorer to restore data. However, you can use the Media Explorer to restore IntelliSnap backup data from the backup copy.

How do I determine the number of streams to be used for a restore operation from an IntelliSnap backup?

For DB2, SAP for Oracle, and Oracle iDataAgents, when restoring from a snapshot using file system, the number of streams depends on the number of mount points used for the restore operation. Similarly, when restoring from a backup copy using file system, the number of streams depends on the number of media groups used for the restore operation.

Can I perform an IntelliSnap backup of RDM disks for an agent from a virtual machine host?

Yes. It is supported to run a IntelliSnap backup operation of Raw Device Map (RDM) disks for any Windows-based Agent configured in a virtual machine. Ensure the iSCSI Initiator is configured on the client computer to access the storage device in order to perform a successful IntelliSnap operation.

What are the commands used for device discovery?

During a IntelliSnap backup job, the Commvault software runs a set of commands to discover storage devices.

The following table displays the commands that are used to list, rescan and delete adapters/devices for each operating system:

Can I create my own commands to perform device discovery?

Yes, you can customize the device deletion and the rescan logic by creating the following additional settings:

After creating the above additional settings, you can use the following script examples:

On Linux Computers

#------------------------------------------------------------------ #Example 1: Linux Rescan Script to be used by RefreshBUS key #------------------------------------------------------------------ #!/bin/sh hba_wwpn=$1 #This line sets $Fc_adapter. (See o/p of scan_fc_adapters.sh) eval `/opt/software/Base/scan_fc_adapters.sh | grep $hba_wwpn | awk '{print $1}'`

#Add your own custom commands here.

#Perform scsi midlevel rescan. (May not be needed if you have your custom scan command above ). echo '- - -' > /sys/class/scsi_host/${Fc_adapter}/scan exit 0

#------------------------------------------------------------------------------ #Example 2: Linux Device Deletion Script to be used by DeleteDevice key #------------------------------------------------------------------------------ #!/bin/sh device=$1

#Add your own custom commands here. #The one below is what Commvault uses.

echo 1 > /sys/block/$device/device/delete

exit 0

On AIX Computers

#------------------------------------------------------------------ #Example 1: AIX Rescan Script to be used by RefreshBUS key #------------------------------------------------------------------ #!/bin/sh hba_wwpn=$1 #This line sets $Fc_adapter. (See o/p of scan_fc_adapters.sh) eval `/opt/software/Base/scan_fc_adapters.sh | grep $hba_wwpn | awk '{print $1}'`

#Add your own custom commands here.

#Perform scan using cfgmgr ( May not be needed if you have your custom scan command above ). cfgmgr –l $Fc_adapter exit 0

#------------------------------------------------------------------------------ #Example 2: AIX Device Deletion Script to be used by DeleteDevice key #------------------------------------------------------------------------------ #!/bin/sh device=$1

#Add your own custom commands here. #The one below is what Commvault uses.

rmdev –d –l $device

exit 0

How does Commvault select target devices during clone or snap operations?

When you configure an storage device using Array Management in the CommCell Console, the Device Group text box defines the target device group where Commvault will move the source and target devices during IntelliSnap backup operations. This option does not specify the source device group (from where a device should be found during Snap/Clone operations).

The following table explains the default behavior for selecting a Snap or Clone target device:

Why is an offline IntelliSnap backup going to the "Backup Pending" state when the SNAP "Backup Pending" parameter is "Yes"?

When you perform an offline IntelliSnap backup when the database is up and running. When the backup is complete, the DB2 configuration parameters (for example LOGARCHMETH1) are modified, which moves the state to "Backup Pending". This is expected behavior.

Clear the "Backup Pending" status by running a traditional offline backup. After that completes, you can run an IntelliSnap online or offline backup.