5 1 0:Backup Overview

Backup Overview

Backup is a process of copying and storing file system and/or application data specified by backup task to savesets onto backup media. SEP sesam supports heterogeneous computing environments and provides preset task types, such as ordinary file system backup (type Path), Exchange, MySQL, SAP HANA, etc. as well as task types for virtual environments enabling image-level backups and single-file restore.

Backed up data on savesets is preserved according to their retention time. Data can be migrated, deduplicated and replicated in order to provide fast and reliable restore.

Note that standard backup does not prepare for disaster recovery. Such recovery requires special preparation and configuration with SEP sesam disaster recovery solutions: Bare Metal Recovery Linux, BSR Pro for Windows and SEP sesam self-recovery.

Automatic backups

SEP sesam provides a powerful scheduling service called SEPuler. It is constantly checking for backup, restore and other predefined tasks to be executed. When such a task is found, SEPuler initiates the execution of the event. To prevent possible tasks conflicts and efficiently manage tasks in the execution queue, SEP sesam uses the event priorities.

Once you have configured your SEP sesam environment and created the required backup tasks for the clients you want to protect, you can schedule the automatic execution of your backups. SEP sesam provides a comprehensive and flexible schedules.

You can create a number of schedules for all types of events. For example, you can create a schedule daily for a series of events or configure multiple schedules (e.g., weekly full, daily incremental) for the same data protection. In addition to the custom and daily schedules, weekly, monthly, and yearly schedules are also available. Note that a schedule must have at least one event assigned to it. For details, see Creating a Schedule.

To minimize failed backups due to unavailable media pool, you can specify a failover backup event when configuring the backup event. In case the configured media pool is not available for writing for some reason (out of space, no free media, RDS cannot be reached) and the backup event cannot be successfully performed, the failover backup event is performed instead. If the failover backup event is activated the data storage settings of the original backup event are replaced with the settings from the failover backup event (media pool, drive, interface, follow up, migration task). The task, backup level and other options (for example, Enforce FULL) of the original backup event are preserved.

The configuration of automatic backups consists of the following:

Step 1: Setting up your backup environment

Step 2: Configuring clients

Step 3: Configuring storage hardware – drives and loaders

Step 4: Preparing backup media

Step 5: Configuring a backup task – select WHAT you want to back up by selecting the source/task type

Step 6: Creating a schedule – select WHEN and at what interval you want to back up

Step 7: Creating a backup event – select HOW (backup level: FULL, DIFF, INC, COPY) and WHERE to backup

For details, see also Standard Backup Procedure.

Backup level (C, F, D, I)

When creating a backup event in the Main Selection -> Scheduling -> Schedules -> New Backup Event, you also have to specify the backup level.

SEP sesam provides four different backup levels: full, differential, incremental and copy. The backup level is specified when creating a backup event in the Main Selection -> Scheduling -> Schedules -> New Backup Event.

The following backup levels are available:

A FULL backup always copies all data specified by the backup task, regardless of whether it has been changed or not. A saveset created as FULL is the basic saveset for subsequent DIFF or INCR savesets. While the backup time of a full backup can be significant, restore is fast and simple since only one backup saveset is required. Information about the backup status is stored in the SEP sesam database. Note that the archive bits are not deleted on Windows systems. If you want to force-reset of the archive bits, you can enter the command -o clear_archive in the backup options.

A DIFF (differential) backup saves only data which was created or changed after the last FULL saveset had been created (of the same task). A differential backup is faster than a full backup, however, to restore the whole data source, first the saveset of the full backup has to be restored followed by restore of the DIFF saveset. For this, SEP sesam provides generation restore that enables browsing for and selecting for restore all generations of backed up files since the last full backup.

An INCR (incremental) backup saves only data which was created or changed after the last backup (FULL, DIFF or INCR) of the same task. This is the fastest backup method and requires the least storage space. Restoring from incremental backups is the slowest, because it requires all related savesets to be copied back – the saveset of the last full backup as well as all INC backups. You should consider the advantages of time and resources when planning your backup strategy. A combination of FULL backups stored to tape drives, and DIFF or INC backups stored to virtual disk media is a common method.

A COPY backup is a full backup that has no influence on following differential (DIFF) or incremental (INCR) backups. For the treatment of archive bits, see FULL backup above. COPY backup is usually used for additional full backups, e.g., monthly backups, or backups for archiving, i.e. removal from storage.

	Note
	In case no initial FULL backup exists, differential (DIFF) or incremental (INCR) backups are automatically performed as FULL backups.

Parallel Backups

SEP sesam supports parallel, i.e., simultaneous backup of multiple data sources onto one drive. This is called Sesam Multiplex Stream (SMS).

The data from the different streams is distributed into packets, each packet is given an identifier and copied to the backup media. The data of a particular stream is not contiguous on the media, but is interrupted by packets of other streams. The identifier of the packets allows SMS to restore the initial stream during reading.

In addition, SMS can split savesets across multiple media where free space is still available (indicated by EOM).

The maximum number of parallel streams that can be used during backup to the backup drive is set in the Drive properties by the Max. channels parameter. The number of available streams depends on the type of server license. For details, see Drives.

Encryption

SEP sesam provides data encryption on different levels: backup-task encryption for savesets (set in the backup task), Si3 encryption for Si3 deduplication store (set in Si3 deduplication store properties), and hardware-based LTO encryption for LTO tape drives (at the media pool level).

For details on the latter two, see LTO Encryption and Encrypting Si3 NG Deduplication Store. See also Encryption Support Matrix.

SEP sesam backup-task encryption for savesets can be enabled when creating a backup task or in the backup task properties under the tab Encryption & Compression. Supported encryption algorithms are Advanced Encryption Standard (AES) 256-bit encryption and Blowfish (bf64) encryption.

You must create an encryption key for the data to be encrypted, but you can decide whether the encryption key (password) is stored in the SEP sesam results database or not.

• If the encryption key is not stored by SEP sesam, you will be prompted to enter it before starting the restore in the restore wizard.
• If the encryption key is stored in the SEP sesam database, the key itself is also encrypted and automatically used for decryption during restore. The data is encrypted before it is transferred over the network and copied to a saveset.

If you change the encryption key, all backups started after the password is changed will be encrypted with the new key. This new key will be stored with the backup and you will have to enter the password to restore your data.

	Note
	A password cannot be longer than 28 characters and cannot contain special characters (underscore, hyphen, etc.) Spaces are also not allowed.

Setting encryption

You can determine which backup tasks are encrypted by checking the backup task properties, tab Encryption and Compression, where you can also reset your password. You can also check the GUI backup results table (Main selection -> Job state -> Backups -> double-click the selected task to open its properties and look for the Encryption field under Info 2) or check the backup task properties in Web UI (click the backup task under Monitoring -> Last backup state or Backups), Settings row. See SEP sesam Web UI for details.

Backup with VSS (Volume Shadow Copy Service) on Windows

Microsoft Volume Shadow Copy Service (VSS) is a Windows service for backing up running applications. VSS coordinates with other VSS-aware applications and services, and creates a shadow copy or snapshot of data for backup purposes. VSS uses a copy-on-write snapshot, allocating a small temporary storage space for it. Once the snapshot is completed, the temporary storage space is freed up again.

Backup with VSS is enabled by default for the file system task type Path. All other task types, for example System State, use the required VSS writer by default.

For details on SEP sesam VSS, how to activate/deactivate VSS and manually exclude a VSS writer from backup, see SEP sesam Volume Shadow Copy Service (VSS) for Windows.

NDMP backup

SEP sesam enables you to protect and manage your storage file servers by providing support for Network Data Management Protocol. NDMP is a common protocol for backing up and restoring data on storage devices that do not support the installation of a backup agent.

It ensures interoperability between NAS file servers and SEP sesam, and is used as an interface that enables SEP sesam to back up various NAS appliances and copy this data to a SEP sesam Server or Remote Device Server. SEP sesam supports version 4 of the NDMP protocol.

For details, see NDMP Backup. For a list of supported NAS appliances, see the support matrix. For details on backing up NetApp NFS volumes via NFS, see NetApp Volume Backup.

HSM-aware backup for Windows

Hierarchical Storage Management (HSM) is a method for reducing the costs of data storage and facilitating data management tasks. HSM-aware backup for Windows is an integral part of the SEP sesam package.

It provides efficient backup of data on Windows systems that is managed by HSM. SEP sesam as an HSM-aware solution recognises the reparse tags in stub files and does not trigger a recall of the original files, but performs a backup of the placeholder files without retrieving their contents. For more details, see HSM-aware Backup for Windows.

Support for NTFS alternate data streams (ADS) for Windows

ADS are backed up by default when backing up an NTFS file system. They are automatically restored to any ADS-aware system. ADS are backed up by default, but can be excluded from backup by using a special option in the backup task properties.

Alternate data streams are a unique data-hiding feature of NTFS file systems. A file in NTFS consists of the unnamed data stream where the data is actually contained, and of alternate data streams that can store additional metadata. Applications may use ADS for storing file attributes. For details, see Support for NTFS alternate data streams (ADS) for Windows.

Support for Linux sparse files

SEP sesam provides support for Linux sparse files to prevent running out of disk space during restore. For details on how SEP sesam handles sparse files and what options are available, see Support for Sparse Files.

SEP sesam Logical Volume Manager (LVM) for Linux

SEP sesam uses LVM (Logical Volume Manager) snapshots to perform consistent backups of open files on Linux distributions. LVM snapshots allow a frozen copy of the file system to be backed up without taking the "live" volume offline during the backup.

LVM snapshots only work with partitions created with LVM. For more details, see SEP sesam LVM for Linux.

See also

Standard Backup Procedure – NDMP Backup – HSM-aware Backup for Windows – Support for NTFS alternate data streams (ADS) for Windows – SEP sesam Volume Shadow Copy Service (VSS) for Windows – Support for Sparse Files – SEP sesam LVM for Linux – Encryption Support Matrix

Copyright © SEP AG 1999-2024. 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.