iSCSI or Internet Small Computer System Interface is an Internet Protocol (IP)-based storage networking standard for storage subsystems. It is a carrier protocol for SCSI. SCSI commands are sent over IP networks by using iSCSI. It also facilitates data transfers over intranets and to manage storage over long distances. iSCSI can be used to transmit data over LANs or WANs.
In iSCSI, clients are called initiators and SCSI storage devices are targets. The protocol allows an initiator to send SCSI commands (CDBs) to the targets on remote servers. It is a storage area network (SAN) protocol, allowing organizations to consolidate storage into data center storage arrays while providing hosts (such as database and web servers) with the illusion of locally attached disks. Unlike traditional Fibre Channel, which requires different cabling, iSCSI can be run over long distances using existing network infrastructure.
iSCSI is a low-cost alternative to Fibre Channel, which requires dedicated infrastructure except in FCoE (Fibre Channel over Ethernet). Note that the performance of an iSCSI SAN deployment can be degraded if not operated on a dedicated network or subnet
The VTL container type is designed to work seamlessly with the iSCSI protocol. For details, see Creating a VTL type container .
This topic describes key specifications of VTL support in QoreStor.
- Supported VTL Types — QoreStor supports two types of virtual tape libraries.
- Standard emulation of StorageTek L700 library
- Quest OEM version of the StorageTek L700 library
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NOTE: The Quest type VTL is supported only with VeritasBackup Exec and Netbackup data management applications (DMAs). |
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NOTE: Refer to the documentation for your specific QoreStor version, which includes DMA best practices whitepapers and the latest QoreStor Interoperability Guide, for a complete list of the supported DMAs. Visit the following site and select your specific QoreStor to download documentation: support.quest.com/qorestor. |
- Number of Tape Drives — Each tape library contains 10 tape drives of the type IBM-LTO-4 (‘ULT3580-TD4’)
- Tapes or Media Sizes— Each library initially is created with 60 slots housing 60 tape media of the default size of 800GiB, which is the equivalent of an LTO4 tape.
You can add additional tapes to the library as needed by editing the container in the GUI or by using the following CLI command:
vtl --update_carts --name <name> --add --no_of_tapes <number>
![](/es-es/technical-documents/image/c7a14ae2-8847-4247-9628-28cbda305378)
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NOTE: For more information about using the CLI, see the QoreStor Command Line Interface Reference Guide. |
A library can only contain tapes of the same size. For example, if the library is originally created with 10 tapes of size 10GB, additional tapes of size 10GB can only be added.
The table below details the tape size and capacity configurations supported by each QoreStor installation type.
Table 6: Supported tape configurations per installation mode
Tape |
Large installation |
Standard installation |
Cloud-Optimized installation |
Size |
Max number of slots supported |
Size |
Max number of slots supported |
Size |
Max number of slots supported |
LTO-4 |
800GB |
2000 |
800GB |
1000 |
800GB |
500 |
LTO-4 |
400GB |
4000 |
400GB |
2000 |
400GB |
1000 |
LTO-4 |
200GB |
8000 |
200GB |
4000 |
200GB |
2000 |
LTO-4 |
100GB |
10000 |
100GB |
5000 |
100GB |
2500 |
LTO-4 |
50GB |
10000 |
50GB |
5000 |
50GB |
2500 |
LTO-4 |
10GB |
10000 |
10GB |
5000 |
10GB |
2500 |
- Maximum Number of DMAs or Initiators Supported — A tape library can be accessed by one DMA or iSCSI initiator at a time.
The overall steps and recommended guidelines for using and configuring a virtual tape library (VLT) with QoreStor are described below.
Plan your Environment
Determine the following before creating a container of type VTL.
- Identify the Data Management Application (DMA) that you will be using to back up data. Refer to the QoreStor Interoperability Guide for a complete list of the supported DMAs.
- For the NDMP protocol, determine the filer that will be backed up using NDMP Refer to the QoreStor Interoperability Guide for a list of the supported Filers and Operating systems.
- For the iSCSI protocol, determine the iSCSI initiator’s properties – This is the DMA IP, hostname or IQN of the software initiator on the operating system.
- Assess the estimated size of full and incremental backups and retention periods.
![](/es-es/technical-documents/image/c7a14ae2-8847-4247-9628-28cbda305378)
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NOTE: The size of the full and incremental backups will determine the tape capacity size that you set. You should use a larger tape size for full backups and a smaller size for incremental backups that have smaller retention periods. Note that faster expiration periods of incremental backups residing on smaller tapes results in the release of space back to the system for future backups. |
Create Containers of Type VTL
- When creating the container in the GUI or by using the CLI, you will need to set the connection type of either NDMP or iSCSI. You need to provide either the DMA IP/hostname for NDMP or the IP/hostname or IQN for an iSCSI connection type.
Refer to the topics, Creating Storage Containers and Creating a VTL Type Container, for detailed instructions about creating containers. Refer to the QoreStor Command Line Interface Guide for details about the CLI commands for creating containers.
Authentication/User Management Considerations
Verify the Tape Library Creation
You can easily check that the library has been created and is available for use by using the following commands.
Configure the Library in the DMA
See the QoreStor documentation, which includes DMA best practices whitepapers for your specific QoreStor version at:
support.quest.com/qorestor.
This chapter introduces the concept of Encryption at Rest as used by QoreStor as well as related concepts and tasks.
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NOTE: Due to export regulations, the encryption at rest feature is not available in certain markets, and, therefore, may not be available in your locale. |