The Backup 4.4
|This is not the latest version of the article and, as such, does not provide information on features and enhancements introduced in the latest release. For the latest documentation, check User Manual.|
Backup is a process of copying and storing file system and/or application data specified by backup task to save sets onto backup media. SEP sesam supports heterogeneous computing environments and provides preset task types (note that the naming was changed from Backup type to Task type in Grolar), such as ordinary file system backup (type Path), Exhange, MySQL, SAP HANA etc. as well as task types for virtual environments enabling image-level backups and single-file restore.
Backed up data on save sets 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, Bare Metal Recovery MS Windows and SEP sesam self-recovery.
SEP sesam introduces 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, a SEPuler initiates the execution of the event. To prevent possible tasks conflicts and efficiently manage tasks in execution queue, SEP sesam uses the event priorities.
You can schedule your backups to run automatically once you have configured your SEP sesam environment and created required backup tasks for the clients you wish to protect. SEP sesam provides a comprehensive and flexible schedules.
You can create a number of schedules for any kind of events. For example, you can create a schedule daily for a number of events or configure more schedules (e.g., weekly full, daily incremental) for the same data protection. Besides the custom and daily schedule, weekly, monthly and yearly are also available. Note that a schedule must have at least one event assigned to it.
Configuring automated backups consist of the following:
Step 5: Configuring a backup task – select WHAT you want to back up: select the appropriate predefined task type (previously called backup type), according to which the data is backed up (default is Path, others are SAP Hana, Exchange Server, Lotus Notes, MySQL, VMware vSphere etc.), specify the data you want to backup (source) and optionally set additional parameters and define pre/post scripts
Step 6: Creating a schedule – select WHEN you want to back up: specify a start time and time interval
Step 7: Creating a backup event – select HOW and WHERE to back up: specify backup level (FULL, DIFF, INC, COPY), event priority and define a target media pool
Backup level (C, F, D, I)
When creating a backup event in the Main Selection -> Scheduling -> Schedules -> New backup event, you also specify the backup level (note that the naming was changed from Backup type to Backup level in Grolar.
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.
|In case no initial FULL backup exists, differential (DIFF) or incremental (INCR) backups are automatically performed as FULL backups.|
SEP sesam supports parallel i.e. simultaneous backup of multiple data sources onto one drive. This is called Sesam Multiplex Stream (SMS).
Modern tape drive manufacturers are dramatically increasing device performance and capacity. Few of today's backup software products are able to fully utilize the new functionality to its greatest advantage. The drive is often in a 'stopped' or waiting mode for data from the backup source.
SEP sesam is one of the few backup software products that can be used for receiving data from other backup sources. Sesam Multiplex Stream now offers up to 124 channels for a single drive. Each of 124 channels can serve one backup source.
Data of the different streams are distributed into packets, each packet is supplied with an identification mark and copied to the backup media. The data of a certain stream is not contiguously positioned on the media, but interrupted by packets of other streams. The identification marker of the packets enables SMS to restore the initial stream during reading.
Furthermore, SMS is able to split save sets across several media that still have some free space left (specified by media properties parameter EOM – End of Media).
The maximum number of parallel streams that can be used during backup to the backup drive is specified under the Drive properties by parameter Max. channels. Note that the number of available data streams depends on the type of Server License, e.g., ONE provides 1 backup stream, Standard provides 5 backup streams while Advanced provides unlimited number of streams (dependent on the system configuration and available throughput).
For details, see Drives.
SEP sesam provides data encryption types on different levels: backup-task encryption for savesets (explained below, set in the backup task), Si3 encryption for Si3 deduplication store (set in the Si3 deduplication store properties), and hardware-based LTO encryption for LTO tape drives (done on a media pool level). For details on the latter two, see LTO Encryption and Encrypting Si3 Deduplication Store. See also Encryption Support Matrix.
SEP sesam encryption for save sets can be enabled in the backup task properties under the tab Encryption and compression for each backup task. Supported encryption algorithms are the Advanced Encryption Standard (AES) 256-bit encryption and the Blowfish encryption. You can select the type of encryption by clicking the Encryption and compression tab in the backup task window (Main Selection -> Tasks -> By clients -> select a client and a task, and double-click to open the properties window).
You must create an encryption key for the data to be encrypted, but you can decide whether the encryption key (password) will be stored into SEP sesam results database or not. If the encryption key is not stored by SEP sesam, you will be prompted to enter it before the restore is started in the restore wizard.
If the encryption key is stored in the SEP sesam database, the key itself is also encrypted and is used automatically for decryption during restore. Data is encrypted before it is transferred over the network and copied to a save set.
You can determine which backup tasks are encrypted by checking the backup task properties, where you can also reset your password, or in the backup results table (Main selection -> Job state -> Backups -> click the selected task to display its properties and look for the Encryption key field).
If you change the encryption key, all backups started after the password has been 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.
|A password cannot be longer than 28 characters and may not use any special characters (underscore, hyphen, etc.) Spaces are also not permitted.|
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.
From SEP sesam client version 4.0, every file system – Path backup of a Windows client has the option to backup with VSS enabled by default. This option is available in the backup task properties and should only be used with the task type (previously called backup 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 exclude a VSS writer from backup manually, see SEP sesam Volume Shadow Copy Service (VSS) for Windows.
As of version 4.4.3., 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 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 backup 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.
HSM-aware backup for Windows
Hierarchical Storage Management (HSM) is a method for reducing the costs of data storage and facilitating data management tasks. Starting with SEP sesam version 4.4.2, HSM-aware backup for Windows comes as 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
As of version 4.4.3, 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.