NetBackup Interview Tutorial

Backup overview

The Backup utility helps you protect data from accidental loss if your system’s hardware or storage media fails. The backup storage medium can be a logical drive such as your hard disk, a separate storage device such as a removable disk, or an entire library of disks or tapes organized and controlled by a robotic changer.

Types of backup:

The Backup utility supports five methods of backing up data on your computer or network.

Copy backup : A copy backup copies all the files you select, but does not mark each file as having been backed up (in other words, the archive attribute is not cleared). Copying is useful if you want to back up files between normal and incremental backups because copying does not affect these other backup operations.

Daily backup : A daily backup copies all the files that you select that have been modified on the day the daily backup is performed.

Differential backup : A differential backup copies files that have been created or changed since the last normal or incremental backup.

Incremental backup

An incremental backup backs up only those files that have been created or changed since the last normal or incremental backup.

Normal backup

A normal backup copies all the files you select and marks each file as having been backed up (in other words, the archive attribute is cleared).

Netbackup  Introduction :

NetBackup provides high-performance backups and restores for a variety of platforms, including Microsoft Windows, UNIX, and NetWare systems.

Administrators can set up schedules for automatic, unattended backups for clients anywhere in the network.

Users can start backups and restores from the computer where they are working. A user can also archive files. An archive operation backs up a file and then deletes it from the local disk if the backup is successful. Once started, user operations are managed by the NetBackup server.

Netbackup Architecture :

NetBackup includes both the server and client software:

◆ Server software is on the computer that manages the storage devices.

◆ Client software is on the computer whose data you want to back up. A server also has client software and can be backed up like other clients.

3-Tier model of Netbackup :

TIER 1  Master Server:

•         Controls all backup and recovery operation.

•         Monitors the backup.

•         All the catalog reside on Master server

TIER 2  Media server:

•         Primarily helps in data movement.

•         Moves data to secondary storage devices (tape or disc) during backup.

•         Extracts data from secondary storage devices during a restore.

TIER 3  Netbackup Client:

•         Backs up data to net backup servers

Introduction to Storage Units

A NetBackup storage unit is a group of one or more storage devices of a specific type and density that attach to a NetBackup server.

There are four types of storage units:

• Media Manager storage units

A Media Manager storage unit uses tape robots, standalone tape drives, or optical disk devices, that are under control of Media Manager

• Disk storage units

A disk type storage unit consists of a directory on a hard disk that stores the backup or archive data.

• NDMP storage units

NDMP storage units are controlled by Media Manager but attach to NDMP hosts and require that you have the NetBackup for NDMP option installed.

• Disk Staging storage units

A disk staging storage unit provides the first storage location in a two-stage process called Disk Staging. In this process, client data is backed up to a disk staging storage unit, then, in the second stage, the data is relocated to another storage unit.

Storage Unit Group :

Storage unit groups allow you to identify specific storage devices as a group. A storage unit group name can be specified in a policy, just as individual storage units can be specified. When a storage unit group is used in a policy, only the storage units specified in the group will be candidates for the backup.

 Backup Policies :

Backup policies define the rules that NetBackup follows when backing up clients. A backup policy can apply to one or more clients. Every client must be covered by at least one backup policy.

There are 4 tabs while configuring a policy

General Attribute Tab : Here we can specify Whether the policy is active and what date and time the policy will go into effect , The type of backup policy, which primarily defines the type of clients the policy is set up to include , The priority that NetBackup gives to the backups for this policy relative to other policies , The storage unit that NetBackup uses by default when backing up clients covered by this policy, Compression .

Schedule Tab : The schedules determine when the backups occur.   

There are two types of schedules

• Automatic schedules back up the backup selection list on all clients in the policy according to the timetables set up in the schedules.
• User schedules specify the times when users can start user backups and archives from the clients.

Client Tab : The client list names the computers that will be backed up according to a policy.

Backup selection Tab : The backup selections list names the files, directories, directives, scripts (used for database policies), and templates (used for Oracle and DB2 policies), that NetBackup includes in automatic backups of clients covered by a policy.

Policy Volume Pool : A logical grouping of volumes to be used for a specific application A volume pool is a set of media used only by the users and hosts designated when configuring the pool. Volume pools are created and media assigned when configuring media in Media Manager type storage devices. It is not available for disk type storage devices.

Checkpoint Restart for Backup Jobs : The Checkpoint Restart Every check box indicates whether NetBackup will take checkpoints during backup jobs based on this policy at the frequency indicated. Taking checkpoints during a backup is beneficial if a backup based on this policy fails. Without Checkpoint Restart enabled, a failed backup based on this policy is restarted from the beginning of the job. By taking checkpoints periodically during the backup, NetBackup can retry a failed backup from the last checkpoint rather than restarting the entire job.

NFS : The Follow NFS policy attribute specifies that you want NetBackup to back up or archive any NFS mounted files that are named in the backup selection list, or by the user in the case of a user backup or archive. The behavior of the Follow NFS attribute depends on the Cross mount points setting

Restore Collect True Image With Move Detection : The Collect True Image Restore With Move Detection policy attribute specifies that NetBackup also collect the information required to detect files and directories that have been moved, renamed, or newly installed and then include those files and directories in incremental backups for this policy.

Compression : The Compression policy attribut specifies that software compression be used for backups of this policy. Compression reduces the size of a backup by reducing the size of files in that backup. In turn, this decreases the amount of media required for storage. Because the compression and subsequent expansion is performed on the client, compression also decreases the amount of data going over the network and therefore the network load. Disadvantages of compression are that it increases computing overhead on the client and also increases backup time

Encryption :The Encryption policy attribute is selectable only if the NetBackup Encryption option is installed and configured. When the Encryption attribute is selected, the server encrypts the backup for the clients listed in the policy.

Collect Disaster Recovery Information :The Collect Disaster Recovery Information policy attribute specifies whether or not you want NetBackup to collect the information required for intelligent disaster recovery during backups of Windows clients using this policy.

Schedules :

When creating or editing a schedule, policy schedule attributes appear on four tabs in the Add New Schedule or Change Schedule dialog. The tabs allow you to schedule the days or dates on which a task will run.

• Attributes tab: Schedule the time and frequency at which a task will run, along with other scheduled attributes.
• Start Window tab: Schedule the time on each day that a task will run.
• Exclude Dates tab: Indicate the dates that you do not want a task to run.
• Calendar Schedule Tab: Schedule the run days for a task by indicating specific dates, recurring weekdays, recurring days of the month.

Name :

Identifies the schedule and appears on screens and messages from NetBackup. Specify a name by typing in the box. The name must be unique.

Type of Backup :

The Type of Backup specifies the type of backup that a schedule will control. Click in the field and select from the drop-down list.

Full Backup : Backs up all the files that are specified in the backup selections list for the policy, regardless of when they were last modified or backed up. These backups occur automatically according to the criteria in the schedule. If you use incremental backups, you must also schedule full backups to perform a complete restore. If you’re performing a raw partition backup, you must select Full Backup.

Cumulative Incremental Backup : Backs up all files that are specified in the backup selections list that have changed since the last successful full backup.

Differential Incremental Backup : Backs up all files that are specified in the backup selections list for the policy that have changed since the last successful incremental or full backup.

User Backup : Initiated by the user through the client interface (Backup, Archive, and Restore interface) and backs up all files that the user specifies.

User Archive : Chapter 3, Managing Backup Policies Schedule Attributes Tab 147 Initiated by the user through the interface on the client and archives all files that the user specifies. An archive is a special type of backup that first backs up the file and then deletes it from the local disk if the backup is successful.

Application Backup : A backup type that applies to all database agent clients.

Automatic Backup : An automatic backup for all database agent clients, except NetBackup for Informix and Oracle.

Automatic Incremental Backup :An automatic incremental backup that applies only to NetBackup for Informix clients.

Automatic Cumulative Incremental Backup :An automatic cumulative incremental backup that applies only to NetBackup for Oracle clients.

Automatic Differential Incremental Backup :An automatic differential incremental backup that applies only to NetBackup for Oracle clients.

Automatic Full Backup : An automatic full backup that applies only to NetBackup for Informix and for Oracle clients.

Synthetic Backups : A synthetic full backup is a backup assembled from a previous, traditional (non-synthesized) full backup, and subsequent differential backups and/or a cumulative incremental backup. A client can then use the synthesized backup to restore files and directories in the same way that a client restores from a traditional backup.

Two types of synthetic backup images can be created: synthetic full and cumulative synthetic.

Instant Recovery Backups to Disk Only :The Instant Recovery Backups to Disk Only option is available when the Advanced Client option is licensed and installed , Perform Snapshot Backups is selected, Retain Snapshots for Instant Recovery is selected.

Calendar Schedule Type : Calendar-based scheduling allows administrators to specify run day options for a task.

Retries Allowed After Runday : Select Retries Allowed After Runday to have the scheduler attempt to complete this schedule until the backup is successful. With this option selected, the schedule will attempt to do this, even after a specified run day.

Frequency Schedule Type : Using the Frequency schedule type, administrators specify how much time must elapse between the successful completion of a scheduled task and the next attempt at the task.

Backup Frequency Determines Schedule Priority : If more than one automatic schedule is due for a client within a policy, the backup frequency determines the schedule that NetBackup uses

For example, NetBackup prioritizes the following three schedules in the order shown:

1.monthly_full (frequency is one month)

2.weekly_full (frequency is two weeks)

3.daily_incremental (frequency is one week)

Multiple Copies : Using the Multiple Copies option, NetBackup can create up to four copies of a backup simultaneously, provided that the storage units are on the same media server and there are sufficient resources available for each copy.

Override Policy Storage Unit : The Override Policy Storage Unit setting specifies whether to use the policy storage unit or another one for this schedule.

Override Policy Volume Pool : The Override Policy Volume Pool setting specifies whether to use the policy volume pool or another one for this schedule.

Retention : The Retention setting specifies how long NetBackup retains the backups it creates according to this schedule. When the retention period expires, NetBackup deletes information about the expired backup, making the files in the backups unavailable for restores.

Media Multiplexing : The Media Multiplexing setting specifies the number of jobs from this schedule that NetBackup can multiplex onto any one drive. Multiplexing sends concurrent backup jobs from one or several clients to a single drive and multiplexes the backups onto the media.

Final Destination Storage Unit : If the schedule is a relocation schedule, created as part of configuring a disk staging storage unit, a Final Destination Storage Unit must be indicated. A Final Destination Storage Unit is the name of the storage unit where the images are swept to from the disk storage unit.

Final Destination Volume Pool : If the schedule is a relocation schedule, created as part of configuring a disk staging storage unit, a Final Destination Volume Pool must be indicated. A Final Destination Volume Pool is the name of the volume pool where images are swept from the volume pool on the disk staging storage unit.

Start Window Tab : The Start Window tab provides controls for setting time periods during which NetBackup can start backups, archives, or disk staging relocation when using this schedule.

Exclude Dates Tab : Use the Exclude Dates tab to exclude specific dates from a schedule. You may want to exclude, for example, the dates of holidays.

Calendar Schedule Tab : The Calendar Schedule tab appears when Calendar is selected as the Schedule type on the Attributes tab of the Schedule dialog. Calendar-based scheduling provides several run day options for use in scheduling when a task will run.

Schedule by Specific Dates : A task can run on specific dates rather than follow a recurring schedule, and specific dates can be added to a recurring schedule. The Specific Dates run day option allows you to schedule specific dates on which your task will run. You can schedule specific dates in any month of any year up to and including December 31, 2037.

Schedule by Recurring Week Days : The Recurring Week Days option provides a matrix that lets you schedule a task for certain days of each week, weeks of each month, or days on particular weeks of the month.

Introduction to the Catalog Application

NetBackup catalogs are internal databases that contain information about the NetBackup configuration and backups. Backup information includes records of the files and the media on which the files were stored.

 The catalogs also contain information about the media and storage devices that are under the control of Media Manager.

NetBackup requires the catalog information in order to recover any backups that have been performed. Therefore, it is extremely important to configure catalog backups before using NetBackup for regular client backups, and to schedule the catalog backups to occur on a regular basis thereafter

The easiest way to configure NetBackup catalog backups is to use the Catalog Backup Wizard.

Catalog Attributes Tab : The Catalog Attributes tab contains general attributes for NetBackup catalog backups.

Media Server : The following setting applies only to NetBackup Enterprise Server: The Media Server setting specifies the name of the NetBackup server to which catalogs backups will be sent.

Last Media Used : The Last Media Used setting shows the media ID (for Removable Media) or absolute pathname (for disk) that contains the last NetBackup catalog backup.

Media 1 and Media 2 Areas : The Media 1 and Media 2 Areas setting specifies the media to use for the catalog backups. You do not have to assign both Media 1 and Media 2. If you do assign both, NetBackup alternates between the media.

Catalog Schedule Tab : The Catalog Schedule tab contains selections concerning when you want to back up the catalogs.

After each session of scheduled, user, or manual backups : Backs up the catalogs after any session that results in the creation of at least one successful backup or archive. This includes automatic, manual, and user backups.

After each session of scheduled backups : Backs up the catalogs after any automatic backup session that results in at least one successful backup of a client. A backup does not occur after a manual backup or a user backup or archive.

Only when manually initiated : Does not automatically back up the catalogs. If you elect to back up catalogs manually, select NetBackup Management > Catalog. Right-click Catalog and select Back up NetBackup Catalog.

Catalog Files Tab : The Catalog Files tab contains the absolute pathnames to the catalog files to be backed up.

Catalog Pathnames : Applies only to NetBackup Enterprise Server: The pathname format depends on whether the catalog is on a master server or a remote media server. It also depends on whether the backup is sent to the master server or to a remote media server.

Introduction to the Activity Monitor

Use the Activity Monitor in the NetBackup Administration Console to monitor and control NetBackup jobs, services, processes, and drives. The Activity Monitor topology view displays the state and configuration of the entire NetBackup system being administered. The Activity Monitor displays only robots and drives that have storage units configured. If a device host has no configured devices, the device host is not displayed in the Activity Monitor either.

Reports Window : The Reports window contains a number of methods to make it easier for you to view report listings and manage report data.

Reports Settings : Use the report settings to specify the following criteria for building your report. Not all

settings are available for every report type.

Date/Time Range : Specify the time period that you want the report to cover. By default, the start time is one

day before the report is run and the end time is the time the report is run.

Select Earliest Available to include the earliest possible data available.

Select Current Time to include all data up to the present.

To set the date and time for all reports, click Set Defaults.

The Global host property, Keep Logs For, determines the period of time for which the

information is available.

Client : Click the Client box and select <All Clients> or the client to which the report will apply.

Media Server : Click the Media Server box and select <All Media Servers> or the name of the media

server to which the report will apply. The master server that is currently selected and its

media servers appear in the report.

Job ID : Specify the Job ID for which you want the report.

Media ID : For media types of reports, specify the media ID or All Media. The Media Contents report requires a specific ID

Volume Pool : For a media summary report, specify the volume pool name or All Volume Pools

.

Verbose Listing: Select Verbose Listing to have NetBackup provide more details in the Media Summary report.

Run Report : Click Run Report after you’ve selected the criteria for a report.

Stop Report : Click Stop Report if a report is running, but you don’t want to wait for it to finish.

NetBackup Report Types

Status of Backups Report : The Status of Backups report shows status and error information on jobs completed within the specified time period. If an error has occurred, a short explanation of the error is included.

Client Backups Report : The Client Backups report shows detailed information on backups completed within the specified time period

Problems Report : The Problems report lists the problems that the server has logged during the specified time period. The information in this report is a subset of the information obtained from the All Log Entries report.

All Log Entries Report : The All Log Entries report lists all log entries for the specified time period. This report includes the information from the Problems report and Media Log report. This report also shows the transfer rate, which is useful in determining and predicting rates and backup times for future backups.

Media Lists Report : The Media Lists report shows information for volumes that have been allocated for backups. This report does not show media for disk type storage units or for backups of the NetBackup catalogs.

Media Contents Report : The Media Contents report shows the contents of a volume as read directly from the media header and backup headers. This report lists the backup IDs (not each individual file) that are on a single volume. If a tape has to be mounted, there will be a longer delay before the report appears.

Images on Media Report : The Images on Media report lists the contents of the media as recorded in the NetBackup image catalog. You can generate this report for any type of media (including disk) and filter it according to client, media ID, or path.

Media Logs Report : The Media Logs report shows media errors or informational messages that are recorded in the NetBackup error catalog. This information also appears in the All Log Entries report.

Media Summary Report : The Media Summary report summarizes active and nonactive volumes for the specified server according to expiration date. It also shows how many volumes are at each retention level. In verbose mode, the report shows each media ID and its expiration date.

Media Written Report : The Media Written report identifies volumes that were used for backups within the specified time period. This report does not display volumes used for NetBackup catalog backups or volumes used for duplication if the original was created prior to the specified time period.

Servers Properties

The Servers properties display the NetBackup server list on selected master servers, media servers and clients. The server list displays the NetBackup servers that each host recognizes.

Master Server : The Master Server property specifies the master server for the selected host.

Additional Servers : Lists additional servers that can access the server specified as Master Server. During installation, NetBackup sets the master server to the name of the system where the server software is being installed.

Media Servers : The Media Servers list specifies that the listed machines are media servers only. Machines listed as media servers can back up and restore clients, but have limited administrative privileges.