What is a Virtual Tape Library?

Virtual Tape Library (VTL) technology is a milestone in the field of data backup. This technology has many advantages such as high performance, low failure rate, high reliability, low cost investment, and low operating costs. Favor.

Virtual tape library

Virtual Tape Library (Virtual Tape Library, referred to as

The concept of a virtual tape library is actually very simple. It is essentially

virtual

Before purchasing a virtual tape library (VTL), you should consider the following issues:

Does VTL support backup software?

After installing the backup software in the VTL, the VTL should function as a media server and be a server that the backup software can identify. The backup program can then automatically record the physical tape replica creation process in the directory. But there are also shortcomings. Once support problems arise, vendors will blame each other; and the upgrade of backup software depends on which operating system VTL supports.

How is the backup software catalog updated?

Most VTLs do not natively support backup software, so backup software needs to understand the tape copy process to ensure that it understands the existence and location of tape copies. Although some VTLs can manage disk-to-tape replicas themselves, they cannot update the catalog of backup software. This requires the administrator to manually update the catalog, or the backup software must read each tape in the library to determine the information in the tape.

How does compression and deduplication work?

Compression and deduplication are essential functions of VTL, but this problem is troublesome when copying data from disk to tape. When migrating data from disk to tape, you must compress the data or reconstruct the data or both, which will increase performance consumption and create a redundant tape copy window. The best way to avoid this is to use a VTL that backs up the data in an uncompressed native format, which makes it easy to copy the data to tape.

In what format is the data stored on tape?

The data storage format copied to tape must be recognized by the backup software. If the process of copying data from disk to tape is controlled by VTL, the backup software may not be able to identify the data format on the tape, making the data unreadable, or the VTL that previously created the tape may be required to recover the data. This makes the data recovery process dependent on VTL.

How does a VTL device manage an existing physical tape library?

VTL handles physical tape libraries in three ways: they don't know they exist, treat them as backup targets, or virtualize them. No one method is better than the other. Understanding how or if VTL manages the tape library can help you optimize the tape library connected to the VTL.

Is the VTL itself a NAS target or a VTL, or both?

For backup software, the NAS target is a large disk pool, while VTL stands for virtual tape target and manages disks as virtual tapes. Using a large disk pool can solve the problem of reduced efficiency caused by virtual tapes (there is unused space in virtual tapes); when data is migrated to tapes, administrators can fill the entire physical tape. However, VTL associates barcodes with virtual tapes; in NAS targets, barcodes are created only when data is migrated to physical tapes. ^[2]