Restarting a dump command backup

Why you might need to restart a backup

You might need to restart a backup initiated by the dump command. The dump command sometimes does not finish because of such internal or external errors as tape write errors, power outages, accidental user interruptions, or internal inconsistency on the filer.

You might also choose to interrupt and restart a backup to avoid periods of heavy traffic on the filer or to avoid competition for other limited resources on the filer, such as a tape drive. A long backup can be interrupted and restarted later if a more urgent restore (or backup) requires the same tape drive. Restartable backups persist across reboots.

What qualifies as a restartable backup

A failed backup to tape can be restarted if it has completed one tape that has ended in phase IV (file data and ACL data).

How to find out whether a backup needs to be restarted

To find out whether a backup is proceeding as expected or has terminated, you can run the backup status command. For more information, see Checking the status of a dump command backup.

How to restart a dump process

To restart a dump process that has been shown to be restartable, complete the following step.

Step	Action
1	From the filer, enter the following command: *dump R[f comma-separated device-list] {path* \|ID}** `f` is an option that enables you to supply a device list. comma-separated device-list lets you direct the dump stream to output devices other than those originally designated in the failed dump. A restarted dump process uses this device list the same way a regular dump would. Any device list that is valid to a regular dump will be valid in this case. If a device list is not specified, the command defaults to the remainder of the devices listed but not yet consumed by the failed dump. For example, suppose the following device list was supplied to the previous dump, which failed while writing to `rst2a:` `rst0a,rst1a,rst2a,rst3a,rst4a` The command would use `rst3a,rst4a` as the default. However, if the original device list contained any non-rewinding (`nrst`) devices or any devices not supported by NetApp, users are required to supply a new device list at restart of the dump. path is the path that is listed in the dump table (the output of the `backup status` command). If there are multiple entries, that is, entries with exactly the same path, the command prompts you to use the ID to restart the dump. ID is the unique ID displayed by the `backup status` command. You can use either path or ID in most cases. Result The command starts rewriting the dump stream from the beginning of the tape file in which the previous dump was interrupted.

Step

Action

From the filer, enter the following command:

dump R[f comma-separated device-list] {path |ID}

f is an option that enables you to supply a device list.

comma-separated device-list lets you direct the dump stream to output devices other than those originally designated in the failed dump. A restarted dump process uses this device list the same way a regular dump would. Any device list that is valid to a regular dump will be valid in this case.

If a device list is not specified, the command defaults to the remainder of the devices listed but not yet consumed by the failed dump.

For example, suppose the following device list was supplied to the previous dump, which failed while writing to rst2a:

rst0a,rst1a,rst2a,rst3a,rst4a

The command would use rst3a,rst4a as the default. However, if the original device list contained any non-rewinding (nrst) devices or any devices not supported by NetApp, users are required to supply a new device list at restart of the dump.

path is the path that is listed in the dump table (the output of the backup status command). If there are multiple entries, that is, entries with exactly the same path, the command prompts you to use the ID to restart the dump.

ID is the unique ID displayed by the backup status command.

You can use either path or ID in most cases.

Result

The command starts rewriting the dump stream from the beginning of the tape file in which the previous dump was interrupted.