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Frequently Asked Questions for DB2 IntelliSnap

Table of Contents

Can I perform an IntelliSnap backup for log files?

Can I perform an IntelliSnap backup while a log file backup job is in progress?

Which volumes are included for the DB2 IntelliSnap backup operation?

Is the volume that contains the Commvault archive log path included in a DB2 IntelliSnap backup?

Can I restore individual tablespaces from IntelliSnap backups?

Are symbolic link paths (also called soft link paths) supported?

What provisioning policies can I use?

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

How are snapshots copied during a backup copy operation?

What should I take into account when the number of jobs determines the retention time?

What UTF setting should I use for volume language?

How is the OnCommand Unified Manager (OCUM) server affected when I delete a snapshot copy?

Is multi-instancing supported?

Can I use Media Explorer to restore data?

How do I determine the number of streams to use for a restore operation?

Can I perform an IntelliSnap backup of Raw Device Mapping (RDM) disks for an agent from a virtual machine host?

What commands are used to discover devices?

Can I create my own commands to perform device discovery?

How does the Commvault software select target devices during the clone operation or the snap operation?

Can I perform an application-free restore (restoring an IntelliSnap backup image on a disk) using the CommCell Console?

Why can't I see the IntelliSnap backup image in the Restore Options dialog box?

Why does the CommCell show the old storage path after I update the path to the database log files?

Can I add a new storage path or tablespace container for an IntelliSnap restore operation?

Can I perform an IntelliSnap backup for log files?

No. During an IntelliSnap backup, log files are not moved to the snapshot copy even if you select the Backup Log Files option in the subclient where the backup operation is performed. Log files always use the traditional backup method, not the IntelliSnap backup method. Even if the data and log files are on the same subclient, the IntelliSnap backup for data and the traditional log file backup run as two separate jobs.

Can I perform an IntelliSnap backup while a log file backup job is in progress?

No. If you perform an IntelliSnap backup while a log file backup job is in progress, the IntelliSnap job might fail. So, we recommend that you avoid performing an IntelliSnap backup while a log file backup job is in progress.

Which volumes are included for the DB2 IntelliSnap backup operation?

All the volumes that include the path listed in db2 "select dbpartitionnum, type, path from sysibmadm.dbpaths" for each database partition that is included in the IntelliSnap operation.

Is the volume that contains the Commvault archive log path included in a DB2 IntelliSnap backup?

No. The log file backup is performed as a traditional backup in a separate job.

If a subclient for a DB2 IntelliSnap backup contains both the data and log files, then the log file backup is initiated with a separate job ID. During the data aging process, if both jobs are full backups, then the backup might be pruned before the log file backup job runs. In this case, the log file backup is an incremental backup, even though the entire set of log files that are available in the  Commvault log archive directory are backed up. The log backups are identified as incremental so that the data and the log file backup operations are included in the same cycle.

Can I restore individual tablespaces from IntelliSnap backups?

No. You cannot perform a partial tablespace restore operation from DB2 IntelliSnap backups. However, you can perform a point-in-time tablespace restore operation from a regular backup image, if the most recent backup image is an IntelliSnap backup on a snapshot copy or on a backup copy. You can restore an entire DB2 database from snapshot backup images on any copy.

Are symbolic link paths (also called soft link paths) supported?

Yes. Symbolic link paths are supported in a UNIX environment. The destination volumes that are referenced by the symbolic links are automatically included in IntelliSnap backups. The soft link directory structure is supported on both NFS and SAN volumes.

What provisioning policies can I use?

Provisioning policies are optional. When you create a 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 create your own provisioning policy, specify it by following the naming convention in the OCUM server:

SnapProtect_provisioning_policy_name

where "SnapProtect_" is the prefix that causes the provisioning policy to be available in the IntelliSnap software.

What happens when a vault  copy 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 might be running on the OnCommand Unified Manager (OCUM) server.
  2. The auxiliary copy job details display the job status as the baseline transfer is in progress.
  3. After the baseline transfer is complete, the IntelliSnap software adds the snapshots to the backup list, and the backup starts on the OCUM.
  4. If SnapMirror is the destination copy, then the IntelliSnap software sends a command to update the mirror.

    The OCUM job is monitored. If the OCUM job completes successfully, then it is identified as complete. If the OCUM job fails, then it is identified as failed.

How are snapshots copied during a backup copy operation?

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

What should I take into account when the number of jobs determines the retention time?

Configuring a storage policy or a snapshot copy with job-based retention is recommended for file system agents and agents that are like file system agents, but not for database agents.

If you use job-based retention, then consider the following scenarios:

  • During a browse operation, deleted files might be displayed for recovery. If the jobs that contain these files are pruned by the retention criteria, then you cannot recover the deleted files.
  • You need to manually delete jobs from deconfigured clients, because the clients no longer run the  Commvault software.
  • When you associate a new storage policy with a subclient, you must perform a new backup so that the backup follows the new storage policy rules. You must manually delete the old backup jobs.

What UTF setting should I use for volume language?

To successfully browse and restore files on a NetApp filer that contains Unicode characters, we recommend that you use the UTF-8 setting for volume language. Please contact NetApp for the implications of changing the volume language.

How is the OnCommand Unified Manager (OCUM) server affected when I delete a snapshot copy?

If you delete a snapshot copy, the following components on the OCUM server are affected:

  • The storage services associated with the snapshot copy are deleted.
  • Datasets that are associated with the deleted storage service are deleted.

    Secondary volumes and datasets are not deleted because they are stored in case you need to perform a restore operation from a deleted dataset. You can delete secondary datasets.

  • Any relationship that is associated with a dataset is deleted within a period of time that is defined on the OCUM 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 the 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 use for a restore operation?

When you restore a snapshot that uses the file system, the number of streams depends on the number of mount points that the software uses for the restore operation. Similarly, when you use the file system agent to restore from a backup copy, the number of streams depends on the number of media groups that the software uses for the restore operation.

Can I perform an IntelliSnap backup of Raw Device Mapping (RDM) disks for an agent from a virtual machine host?

Yes. You can run an IntelliSnap backup operation on RDM disks for any Windows-based agent that is configured on a virtual machine. Before you run the backup operation, verify that the iSCSI initiator can access the storage device.

What commands are used to discover devices?

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

The following table displays the commands that the Commvault software uses  to list, rescan, and delete the adapters and devices for each operating system:

Operating System

Commands that scan fibre channel adapters

Commands that rescan fibre channel adapters

Commands that rescan ISCSI devices

Commands that delete devices

AIX

<Base>/scan_fc_adapters.sh

cfgmgr -l <hba_name>

cfgmgr -l <iscsi_adapter>

rmdev -d -l <hdisk_name>

HP-UX

<Base>/scan_fc_adapters.sh

  1. Command that obtains the path for the host bus adapter (HBA):

    ioscan -unfC fc

  2. Command that scans the HBA path:

    ioscan -H <HBA_path>

N/A

For legacy HP-UX (earlier than 11.23):

rmsf –a <device>

For non-legacy HP-UX:

  1. Command that obtains persistent name mapping:

    ioscan –m dsf

  2. Command that checks the device availability:

    ioscan –kNF device

  3. Command that deletes the device:

    rmsf –H device

Linux

<Base>/scan_fc_adapters.sh

  1. Command that performs the hardware loop initialization (LIP):

    echo 1 > /sys/class/fc_host/<$host>/issue_lip

  2. Command that performs a SCSI mid-level rescan:

    echo '---' > /sys/class/fc_host/<$host>/scan

  • For Red Hat 4 computers:

    /sbin/iscsi -rescan

  • For SuSE Linux 9 computers:

    /etc/init.d/iscsi reload /bin/rescan-scsi-bus.sh -r –L 512 –w –c --nooptscan

  • For SuSE Linux 10 and Red Hat 5 computers:

    /sbin/iscsiadm -m session -R

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

Solaris

<Base>/scan_fc_adapters.sh

cfgadm -c configure <controller>

devfsadm -i iscsi

devfsadm -C -c disk

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.

Initiate a Custom Script That Deletes Devices at the Operating System Level

After the additional setting deletes the devices, the Commvault software removes the LUNs from the storage arrays.

Use this additional setting if you need to unmount snapshots that are mapped to either the proxy or source machine. The additional setting will delete all devices mapped to the machine.

  • To the DB2 client, add the additional setting as shown in the following table.

    For instructions on how to add additional settings from the CommCell Console, see Add or Modify an Additional Setting.

    Property

    Value

    Name

    DeleteDevice

    Category

    Db2Agent

    Type

    String

    Value

    The full path to the script. The device name will be passed as an argument.

Initiate a Custom Script for Each Host Bus Adapter That Needs to Be Rescanned

Use this additional setting  to rescan the computer for any new devices each time that you mount or unmount a snapshot.

  • To the DB2 client, add the additional setting as shown in the following table.

    For instructions on how to add additional settings from the CommCell Console, see Add or Modify an Additional Setting.

    Property

    Value

    Name

    RefreshBUS

    Category

    Db2Agent

    Type

    String

    Value

    The full path to the script. The WWPN of the adapter will be passed as an argument.

After you add the DeleteDevice and RefreshBus additional settings, 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
#------------------------------------------------------------------------------
#!/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
#------------------------------------------------------------------------------
#!/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 the Commvault software select target devices during the clone operation or the snap operation?

When you configure a storage device using Array Management in the CommCell Console, the Device Group box defines the target device group where the Commvault software moves the source and target devices during IntelliSnap backup operations. The Device Group box 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:

Array Management options

Target device is selected from

Source and target devices are moved to

Device Group is not specified.

Use devices only from this device group is not selected.

Any device in the array

CV_PROTECTION_GROUP device group

Device Group is not specified.

Use devices only from this device group is selected.

CV_PROTECTION_GROUP device group

CV_PROTECTION_GROUP device group

Device Group is specified.

Use devices only from this device group is not selected.

Any device in the array

The device group that is specified in Device Group

Device Group is specified.

Use devices only from this device group is selected.

The device group that is specified in Device Group

The device group that is specified in Device Group

Can I perform an application-free restore (restoring an IntelliSnap backup image on a disk) using the CommCell Console?

No. You can restore a regular backup image only to a location on a disk.

Why can't I see the IntelliSnap backup image in the Restore Options dialog box?

The Commvault software uses a file system backup, so there is no backup image for the restore. You can see the backup images on the Recover Database tab on the DB2 Restore Options dialog box.

Why does the CommCell show the old storage path after I update the path to the database log files?

After you change the path to the database log files, to view the updated path in the Restore Options dialog box (path to the dialog box), you must restart the database and run a full backup operation.

Can I add a new storage path or tablespace container for an IntelliSnap restore operation?

No. For an IntelliSnap restore operation, the source and target are balanced. That is, if the source database has only one storage path, then, after the redirect restore operation, the target database has only one storage path.

Last modified: 1/9/2018 7:05:48 PM