5 0 0:Tape Management

From SEPsesam
Jump to: navigation, search
This page contains changes which are not marked for translation.

Copyright © SEP AG 1999-2021. All rights reserved.

Any form of reproduction of the contents or parts of this manual is allowed only with the express written permission from SEP AG. When compiling and designing user documentation SEP AG uses great diligence and attempts to deliver accurate and correct information. However, SEP AG cannot issue a guarantee for the contents of this manual.

Docs latest icon.png Welcome to the latest SEP sesam documentation version 5.0.0 Jaglion. For previous documentation version(s), check SEP sesam Documentation.


Overview

SEP sesam provides efficient backup media management for all common physical media types (disk, tape, and cloud (object) storage). It also provides some specific tape management tasks and features for tape storage.

All tape management operations are recorded in the audit trail. For details, see Audit Logging.

Terminology

  • Barcodes can be used instead of tape labels in a tape library with barcode support.
  • The inventory stores the list of known tapes (and their status information) and is checked by a process called archive adjustment. This compares tape media in the loader with the SEP sesam media archive database.
  • Saveset is a set of data, such as files and directories, copied to backup media by backup or migration. The period for which a saveset is retained is defined by the retention time (EOL). You can verify savesets after the backup is complete by configuring a follow-up event.
  • Tape drive is the device used to read and write data to tape. They can be standalone drives or drives in the tape library.
  • Tape labels are used to uniquely identify a tape. Each medium (a tape cartridge or virtual tape) is given a unique label that is written to the beginning of a medium during initialization. The label consists of the pool name (e.g., DAY, WEEK, MONTH) and a five-digit number that is automatically assigned by SEP sesam to each medium in the selected pool. See Checking and Labeling Tape Media.

Features

Some of the features are:

  • Protection against overwriting savesets with expired retention when they are part of a backup chain with dependency-based retention strategy performed by Automatic Retention (EOL) Management.
  • Media pools that enable you to group large sets of media according to your needs without having to worry about each individual medium.
  • Spare pools prevent failed backups due to missing media.
  • Recording and tracking of all media and their status: used capacity, EOL, user-defined write protection, etc.
  • Barcode support.
  • Media selection is triggered by setting events that execute media selection strategies, reinitialize media, and prepare media for scheduled backups. See Creating a Media Event.
  • Support for EOM (end of media): SEP sesam automatically requests a new medium from the appropriate media pool when the tape is full.

Tape storage configuration

SEP sesam can detect and automatically configure storage hardware in your environment if the hardware is supported and recognized by the operating system (it must be listed in the OS device manager), where the SEP sesam Server or Remote Device Server is installed. A list of supported hardware is available at Supported Storage Hardware.

There are certain types of loaders (also called tape library or autoloader) where the connection between loader and drives cannot be recognized automatically. You have to manually verify and configure such devices. You must also manually configure each backup device that is connected after the SEP sesam installation. For details, see Configuring a Loader.

Media pool configuration

With loaders, you set up a media pool that will be used to back up directly to tapes. All tapes managed by SEP sesam belong to a specific media pool. Once a pool is configured, four tabs are available in the media pool properties. For details on configuring a media pool, see Configuring a Media Pool – Spare Pool.

Media Pool
It shows the Drive group and the Retention time [days] setting; the retention time of a media pool is used as the basis for determining the expiration date (EOL) of the backed up data. The retention time is applied to all tapes in the same media pool. During the retention period, SEP sesam does not overwrite the data on the tape. The tape media EOL follows a different logic than the individual savesets stored in a data store: the tape is not re-used until all savesets on it have expired. For more details, see the Tape availability and data-protection section below.
Readability Check
This check is used to verify the readability of the data on the tape and its structure, and to ensure that the savesets on the tape are recorded in the database and vice versa. For details, see Configuring a Readability Check.
Encryption
SEP sesam provides native support for managing LTO hardware-based encryption by enabling LTO encryption of tape drives at the media pool level. For details, see LTO Encryption and Encryption Support Matrix.
Options
These settings control the usage and sharing of media across media pools. SEP sesam automatically selects the most appropriate media for backup based on the get_oldest strategy. You can specify how media are selected for backup based on media allocation criteria, including using any appropriate media for backup (unknown media and/or media with expired EOL) and using media from the SPARE (if configured) and/or another pool.

Get_oldest policy

When there is a single media pool linked to a media event or schedule, the GET_OLDEST policy is always applied. This preserves the data on the media for as long as possible.

If the media event includes a specific label, the system will attempt to locate it and load it into a drive. The autoloader magazine must be accessible to SEP sesam or the backup will be blocked.

The GET_OLDEST strategy determines which media to use next. The tape media are prioritized according to the following criteria:

  • Media with expired media EOL (expired EOL of all savesets on tape).
  • The oldest media – media with the oldest locked until (is backup day + media EOL) date in the media pool.
  • Media that is not write-protected (locked).

Spare pools

A spare pool is a media pool that you can configure to allow sharing of spare media across media pools; spare pools are used by media events when media from the actual pool are inaccessible. Spare media are automatically moved from the compatible spare pool to the pool currently being accessed by the backup, thus reducing administrator intervention due to media unavailability. Migration of spare media to the working pools results in a dynamic increase of the media pool size, depending on the amount of data being backed up. The use of spare pools is optional.

A spare pool has some characteristics you should consider before using it.

  • The name of a spare pool must begin with SPARE_.
  • Each drive type requires its own compatible spare pool with free media.
  • Is different from a regular pool and should not be used for allocation.
  • You cannot move protected media into a spare pool.

Media are moved between a regular and spare pool on two occasions:

  • If there are no more free media in the regular pool, then SEP sesam allocates media from the spare pool and moves them to the regular pool.
  • When all data on the media expires (and the media is in a regular pool), the media can be moved to the spare pool?

For details on configuring a spare pool, see Configuring a Media Pool – Spare Pool.

Tape management

Tapes used by SEP sesam belong to one of the media pools. They are displayed in the Components -> Media view and Media Pools view.

Initializing media

You need to initialize media (tape cartridges, removable drives, etc.) before you use them for backup. However, when adding new media with the options Accept without initialization and Automatically assign next number, initializing the media as a separate step is not required. SEP sesam initializes new media automatically when they are selected for backup.

The initialization process writes unique identification information to media used by SEP sesam to perform backup and restore operations. The identification label is placed at the beginning of the media during physical initialization and is used for identification during backups and restores. Its information is entered into the SEP sesam database. SEP sesam keeps track of all media that are loaded into tape libraries and their status.

To initialize media, go to Activities -> Immediate Start -> Media Action. Choose Media action init, select the Media Pool and the Media you want to initialize. Click OK to start the initialization of the medium. Initializing media can also be configured to run automatically. For details, see Initializing media.

Adding new media

Select the media pool to which you want to add the media: In the Components -> Media Pools, right-click the tape media pool you created earlier and click the New Media button. In the Adding a New Media window, specify the appropriate Media Pool, Drive, Type. By default, the options Accept without initialization and Automatically assign next number are selected so that SEP sesam can determine a sequential number for the label, initialize the cartridge and add the media to the database.

SEP Tip.png Tip
When adding a large number of tapes to a loader at once, use the automated method; fill the magazine with raw media and then go to Main Selection -> Loaders, right-click the target loader and select Archive adjustment. For details, see Setting up Archive Adjustment.

Archive adjustment: Automatic introduction of a new tape

An archive adjustment is required whenever the contents of your loader have changed. Typically, you need to perform archive adjustment whenever new media or used media that have not yet been registered (initialized) by SEP sesam are inserted to identify unrecognized tapes. For details, see Checking and Labeling Tape Media. For details, see Setting up Archive Adjustment.

Migrating media

Migration is the process that creates an identical copy of the saveset data to a newly created saveset. It is only available after a backup has been performed. You can move either the original media or the copies offsite (to a safe location) for long-term data retention and keep the other set of media on site for restore/recovery purposes.

Readability check

Used to check the readability of the data on the tape and its structure. The check involves reading the data on the tape media in blocks, and checking and recording the structure of the tape. It also checks whether all the backup sets on the tape are recorded in the database and vice versa.

  • Readability check can be set up at the media pool level, configured by a special media events, or started immediately. For details, see Configuring a Readability Check.
  • The readability check can only be applied if media EOL has not expired; it is not applicable to EOL-free media.

Checking and labeling tape media

Each medium, whether a tape cartridge or a virtual tape in a VTL, is given a unique label for identification. The label is written to the beginning of a medium during initialization. The media label consists of the pool name (e.g., DAY, WEEK, MONTH) and a five-digit number which is automatically assigned by SEP sesam to the respective media of the selected pool.

In the standalone tape drive environment it might happen that multiple tapes are incorrectly labeled with the same label. In this case, you have to manually identify the tape with the original label that was duplicated to resolve duplicate media label conflicts and avoid problems with potential data loss. For details, see Checking and Labeling Tape Media.

Filtering media

You can use Filter in the Components -> Media view to search and select media in a media pool or storage device. Filtering can be done based on EOL, i.e. by specifying the availability of the tape in time. Filtering helps locate and select specific media without browsing the entire media list.

Setting write protection

By default, all media in SEP sesam have write protection disabled as it is recommended not to use write-protected media with SEP sesam. However, you can manually set the write protection switch on in media properties (Properties 1 - Write protection). When write protection is enabled, all write operations, such as initialize, backup, and delete will abort the job OR skip the write-protected media. Such media will not be used for backups even if their EOL has expired.

Deleting media

When you no longer need the data stored on tape, you can delete (erase) tapes. There are two ways to delete data: normal Delete by clicking the Delete button or checking the special checkbox Delete all metadata and re-initialize tape.

  • Normal delete removes the tape's metadata and deletes the media from the SEP sesam database.
  • Selecting the checkbox Delete all metadata and re-initialize tape and then clicking the Delete button erases all metadata of the tape media and initializes the tape provided that the tape is available to SEP sesam; if it is, the tape is loaded into a drive and physically erased, removing access to all existing data on the tape.
Information sign.png Note
You cannot delete tapes with existing EOL. To erase such tapes, you need to expire their EOL and remove the protection.

Delete media.jpg

Creating a media event

A media event can be a user-defined event or an internal event created by SEP sesam. For example, if the specified media are not available when a backup is started, or if the end of media (EOM) is reached during data transfer, SEP sesam creates an internal media event that determines the next media for the backup.

SEP recommends performing regular media-related checks, such as the readability check and archive adjustment, to ensure optimal media selection and preparation for backup. Readability checking can be specified when configuring a media pool (or later in the media pool properties) or triggered by a media event. For details, see Configuring a Readability Check and Creating a Media Event.

Monitoring media actions

You can monitor media-related events for the selected media in the Media view (double-click to open Media properties) in GUI or use Web UI Dashboard -> Monitoring -> Media actions) to check the details of all performed media events (event type: initialize, purge, readcheck..., status, start time, duration etc.). For more details on Web UI and its various monitoring and reporting features, see Web UI Dashboard and Monitoring.

Viewing tape properties

You can view the properties of any media used by SEP sesam in the Components -> Media view. The Properties window displays characteristics, such as the media label, barcode, write protection (on/off) status, storage location, media type, corresponding media pool, etc. Double-clicking the selected media opens the Media Properties window, where you can view and edit some tape media properties. For example, in the Properties 2 view you can check the tape occupancy – the size of currently stored data and the total tape capacity (note that the tape capacity is identified by the tape device in which the tape is located OR specified by the media manufacturer?), and also change any of the following options:

  • Properties 1: Write protection, Locked until, Loader, and Slot (better use archive adjustment!)
  • Savesets: Backup EOL, Locked. Double-clicking the task (saveset) opens the associated saveset window with additional information, such as:
    1. Info 1: Information about saveset, backup level, drives, backup EOL, etc.
    2. Info 2: Information about media number, backup source, SBC start and runtime, status of encryption and compression, etc.
    3. Main Log: The log of events that occur during a backup job (startup/shutdown information, errors, etc.), including EOL change, depending on the configured log level.
    4. Trace log: Detailed information about the backup process (depending on the configured log level) that can be used for analysis and debugging purposes.
    5. Information sign.png Note
      The Trace log tab is only available in the Expert UI mode. If you run the GUI in Basic or Advanced UI mode, you must first change the mode to Expert as described in Selecting the UI mode.
    6. Savesets: Lists all currently saved backups; see also the next section Viewing savesets on tapes. To learn how to check the backup dependencies, see Backup Chain Dependencies.

Viewing savesets on tapes

You can use the saveset tree view in Media view (double-click to open Media properties -> tab Savesets -> double-click the task -> tab Savesets) to determine dependencies and EOL of an FDI backup chain. This information is useful if you intend to shorten or extend the EOL parameter to avoid breaking the backup chain.

The saveset tree overview displays details about a saveset along with potentially dependent savesets that belong to the same backup chain. It provides immediate information about the location and status of the savesets available for restore. By checking the summary, e.g., availability 5, you can search for savesets that are not readily available and then migrate them to enable mounting and selective restore. For more details, see Backup Chain Dependencies.

Tape availability and retention

Typically, you specify a retention time for data when creating a media pool. This retention time is used as the basis for determining the EOL (End of Lifetime) for backed up data. It specifies the time period for which the backed up data is protected after it is written to the media, thus preserving the savesets and keeping them available for restore. The retention time period begins on the date a saveset is written to the media and defines the expiration date (EOL) after which the saveset may be deleted. When the protection expires, SEP sesam can re-use the media for new backups.

There are some special rules for tape media retention: The tape media EOL always corresponds to the maximum retention time (the longest EOL) identified on the tape; if a tape contains multiple savesets, it will expire when the saveset with the longest EOL expires. Only when the retention time of all savesets on the tape has expired and the tape is no longer locked (write-protected) can the tape be used again.

Information sign.png Note
The tape media EOL may also depend on savesets that are not stored on the same tape. This is the case if the tape contains savesets that reference FULL/DIFF/INCR savesets stored on other media or even data stores. For this reason, SEP sesam maintains control over dependencies between individual backup savesets and provides dependency-based automatic retention (EOL) management. That is, if a tape contains a saveset that is part of a backup chain that spans from one tape to another tape or disk storage, it will not expire until the saveset with the longest EOL expires.
SEP Tip.png Tip
The tape media EOL can be checked in the Media view (Components -> Media) as Media EOL and in the media properties as a Locked until setting.
Changing tape EOL

It is not recommended to adjust EOL manually. This will override the EOL defined by the retention time (in the media pool configuration) and started on the date a saveset is written to the media. Manual EOL adjustment should be used for special cases and exceptions, e.g., to increase the retention time of a specific backup chain that needs to be kept longer than defined by the current EOL, or to re-use the tapes with outdated data by setting a shorter retention time.

Information sign.png Note
Extending the backup EOL of savesets stored on tape media may extend the EOL of the tape media! Savesets stored on tape media cannot have a specific retention period set that would apply to only one of the stored savesets. Each saveset stored on tape has its own EOL, but this does not represent the actual expiration date of the tape. The tape media EOL is the maximum EOL of all savesets stored on the same tape. The tape media EOL may also depend on savesets that are not stored on the same tape. This is the case if the tape contains savesets that refer to FULL/DIFF/INCR savesets stored on other media or even data stores.

To decrease or increase the tape media EOL, you can adjust the media EOL (identified by the tape label and displayed in the Media view in the Media EOL column) or change the Locked until setting in tape properties. The extended EOL may affect all savesets on the tape.

SEP Tip.png Tip
If the tape media EOL date has been reached, but you do not want to reuse the tape, you can simply lock the tape by setting Write Protection to On in the media properties. Write protection overrides the media EOL (and retention settings of the media pool) and prohibits overwriting, deleting, or appending data to the protected tape while protection is enabled. It is recommended to use it only in special cases, e.g., to protect media that contain extremely valuable data.
Expire tape

You can expire tape media containing data you no longer need when the EOL of all savesets stored on the tape has expired and the tape is not locked (write-protected) by using the right-click Expire function in the Media view or opening the tape properties and clicking the Expire Media button.

When the protection expires, SEP sesam can use the tape for backups again. Unlike the Delete function, expiring the tape only removes the metadata of the tape; it does not remove the tape media from the SEP sesam database. Clicking the button Expire Media opens a dialog with two options:

  • Delete all metadata removes the tape's metadata but leaves the tape media listed in the database.
  • Delete all metadata and re-initialize tape erases all metadata of the tape media and initializes the tape (if the tape is loaded into a drive), removing access to all existing data on the tape.

Expire media.jpg

Setting tape media rotation strategy

Backup tape rotation is an essential part of any backup plan. There are many tape media rotation strategies you can use to back up your data; perhaps the most established is the GFS backup rotation strategy, where backups rotate daily. While this strategy has proven to be efficient, its main drawback is that backups are only stored on tapes, so GFS does not provide optimal protection against data loss. To learn more about how to successfully protect your environment, see Backup Strategy Best Practices .

Restore data from tape media without SEP sesam DB

There are two ways to restore SEP sesam Server from tape via sbc when SEP sesam database is not available:

Troubleshooting

  • If backup to tape fails, you can analyze the log files to identify operations that caused errors and to track or audit changes to data.
    SEP sesam creates two log files for each backup day: the status file and the day log, located in SESAM_VAR/log. The error log is the subset of the full day log where only error messages are recorded. You can check the backup logs in the GUI (Main Selection -> Logging -> State/Day/Error Log) or online in the Web UI. For example, a media init error may cause the backup to fail. For details, see Analyzing SEP sesam Log Files.
  • For a list of problems with tape media in SEP sesam environment, see Tape and tape devices troubleshooting.

See also

Managing Devices and MediaSetting up Archive AdjustmentConfiguring a Readability CheckConfiguring a Media EventAutomatic Retention (EOL) ManagementGFS Backup Retention StrategyBackup Strategy Best Practices