Virtual Tape Library Slots

    • A disk-based backup system, a virtual tape library (VTL) emulates physical tapes.

  1. I reused one of tape magazines from the old library in the new one. Needless to say I ended up on the well trodden path of DPM 2010 now showing me 2 tape libraries with one of them being offline. But just for the added twist, half my slots showed on the old library and half on the new one.
  2. A repository includes at least one virtual tape library, which includes virtual tape drives, virtual cartridges, and slots. A virtual robot moves virtual cartridges among virtual slots and drives.

In addition, each virtual library must have at least one drive and one slot assigned to it. Select the number of slots to be assigned to this virtual library. Note: Slots assigned to a particular virtual library are sequential and cannot be shared with other virtual libraries.

    • Virtual tape libraries (VTLs) ingest data over a Fibre Channel interface, which enables seamless integration with many existing backup infrastructures and processes. However, most backup software supports direct backup to disk over standard file protocols such as Network File System (NFS) and Common Internet File System (CIFS), eliminating the requirement to emulate tapes.

    • Cloud Storage – Data Storage

      Dell EMC ECS is an object storage platform that empowers organizations to use Cloud storage for unstructured data.

    • Traditional VTLs can only provide a front-end, fast cache to a tape library infrastructure, temporarily alleviating backup window problems. These systems can't cost-efficiently retain backup data for any length of time, and backup data is too large to be replicated or 'vaulted' over a wide area network (WAN). They don't offer an evolution from tape and its associated challenges so that, ironically, tape remains the primary method of retention, recoverability, and disaster protection.

      However, EMC Data Domain VTL software eliminates tape-related failures by enabling all EMC Data Domain systems to emulate multiple tape devices over a Fibre Channel interface. Data Domain VTL software emulates up to 64 virtual tape libraries with up to 540 linear tape-open (LTO)-1, LTO-2, or LTO-3 virtual tape drives. Our VTL software provides up to 64,000 virtual slots and an unlimited number of virtual tape cartridges, with the ability to dynamically change the number of virtual slots and cartridge access ports.

    • The ability to easily integrate with an existing Fibre Channel or tape-based infrastructure is the main benefit of a VTL. Data Domain VTL software is qualified with leading open systems and IBM enterprise backup applications, easily integrating into existing Fibre Channel storage area network (SAN) backup environments.

      Data Domain systems simultaneously support data access methods through VTL over Fibre Channel, remote Network Data Management Protocol (NDMP) access over Ethernet for network-attached storage (NAS), Network File System (NFS) and Common Internet File System (CIFS) protocols over Ethernet, and EMC Data Domain Boost. This deployment flexibility along with simple administration means that users can rapidly adjust to changing enterprise requirements.

    • Data Storage

      Dell Technologies provides a broad range of enterprise data storage solutions and products to solve the data storage challenges.

    • File Storage – Data Storage

      Dell Technologies provides a family of scale-out, network-attached file storage systems designed to simplify management of the most demanding enterprise file workloads.

    • Tiered Storage – Data Storage

      Dell Technologies offers tiered storage solutions to minimize the complexity of managing tiered storage, enabling greater automation and easy scalability.

NOTE: For backups from iSeries hosts, add the following line to /quadstorvtl/etc/quadstor.conf (create the file the first time)

Click on the 'Virtual Libraries' menu to get a list of the currently configured VTLs as shown in the figure below

Click on the 'View' link to view the configuration of a specific VTL

Virtual Tape Library Slots

Click on the 'Add VTL' button to add a new VTL. A form is displayed as shown in the figure below

In the above form

  • VTL Name is the name of the VTL. A valid name can only contain alphabets and numbers
  • Library Type is the type of tape library to emulate. Changing the Library Vendor will display the libraries emulated for the vendor
  • VDrive Type is the type of tape drives to emulate. Currently a VTL can only have a single type of tape drive emulation. (Mixed mode libraries are not supported)
  • Number of VDrives specify the number of tape drives to emulate
  • Number of VSlots specify the number of storage slots to emulate. The maximum number of storage slots is 60000 per VTL
  • Number of IE Ports specify the number of changer access ports to emulate. This can be between 0 to 200
  • Drive Start Address specifies the starting element address to report for the tape drives. Similarly for the storage slots the Slot Start Address and for the I/E port the IE Start Address.

Click on submit.

In the next page as shown below you will be able to add additional virtual drives.

Click on the 'Add VDrives(s)' button to add additional virtual drives. These drives can be of a different type as shown in the figure below

Virtual Tape Libraries

Click on 'Submit' to take you back to the 'Add VTL' configuration page. If you wish to cancel adding additional drives click on Cancel.

Click on the 'Add VTL' button to create the VTL configuration

On a successful addition the VTL configuration of the newly added VTL is displayed as shown in the figure below

To delete a VTL click on 'Virtual Libraries' and then 'View' for that VTL and then click on the 'Delete VTL' button

Modifying a VTL configuration

Click on 'Modify VTL' to modify a VTL configuration. A form is displayed as shown in the figure below

Replication Host is the IPv4 address of a remote VTL system. When this property is set, auto-replication is enabled for this VTL instance and when a vcartridge is unmounted or moved into an import/export port a replication job is queued for the vcartridge

Replication VTL is the name of the VTL on the remote VTL instance. If this value is not specified, the replication is done to a VTL with the same name. If the remote VTL instance does not exist, a VTL with similar properties as the source VTL is created

Replication is enabled for a VTL by default. Auto-replication job for a vcartridge is started only when replication is enabled for the VTL.

Deduplication is enabled for a VTL by default. This can be disabled by unselecting the 'Deduplication' checkbox. For vcartridges in non-deduplication storage pool changing this value for the VTL has no effect.

Click on Submit for modifying the VTL properties and click on Cancel to go back to the VTL configuration page

Configuring virtual cartridges

To add a vcartridge click on the 'Add VCartrige' button. A form is displayed as shown in the figure below

Select the storage pool to which the vcartridge(s) will belong. Specify the number of vcartridges to create. Select WORM if WORM property needs to be enabled for the vcartridges created

If the number of vcartridges is greater than one then the label will be of the following format

LTO000

AAA000

If for example the number of vcartridges is 2 then the labels for the newly created cartridges will be LTO000L6, LTO001L6 etc. If WORM were selected then the labels for the newly created cartridges for our example will be LTO000LU, LTO0001LU etc.

If the number of vcartridges is one then the label can be any length upto 32 characters.

Only alphabets a-z, A-Z and numbers 0-9 are accepted for a label/prefix

Click on Submit to add the specified number of vcartridges. The specified number of vcartridges will be created as shown below

The description of the columns shown are as below

Virtual Tape Library Slots Downloads

Free virtual tape library
  • Pool: The storage pool of the vcartridge
  • Label: The vcartridge barcode label
  • Element: The library element the vcartridge is currently in. This is 'unknown' if the vcartridge has been exported out of the ibrary
  • Address: The library element address of the vcartridge
  • WORM: Yes indicates that the vcartridge is a Write Once Read Many (WORM) vcartridge. Overwrites to existing data is not allowed
  • Size: The capacity of the vcartridge in GB
  • Used: The capacity of the vcartridge used. The actual physical space used by the vcartridge can be lower than this because of deduplication. This value represents the capacity of tape that would have been utilized when there is no deduplication
  • Data Size: The size of data received from a host and written to the vcartridge.
  • Status: Status can have the following values
  • Active: The vcartridge is active in one of the tape library elements and can be data can be written to it or read from it
  • Vaulted: The vcartridge has been moved to a virtual vault outside the VTL instance. An inventory of the VTL will no longer report the vcartridge as a part of the library. The vcartridge can be unvaulted by clicking on the 'Unvault' link that will be shown in the 'Unvault' column
  • Load Error: There was a problem in loading back the vcartridge metadata from disk
  • Replication Pending: Replication for the vcartridge is pending or in progress
  • Export Pending: Tape export for the vcartridge is pending or in progress
  • Load/Unload: The 'Load' link can be used to select the drive to mount the vcartridge. If a vcartridge is mounted an 'Unload' link is shown instead and this link can be used to unmount the vcartridge
  • To delete a vcartridge select the vcartridge in the checkbox on the right and click on 'Delete VCartridge' button. Up to 64 vcartridges can be selected and deleted at a time.

Custom VCartridge size

Depending on the type of vcartridge that is to be created, the size of the vcartridge is determined. For example a LTO 1 vcartridge will have have a size of 100 GB. It should be noted that space for vcartridge is only allocated when needed in 64 MB chunks. This behavior can be changed by specifying a MaxVCartSize in /quadstorvtl/etc/quadstor.conf.

For example the following line in /quadstorvtl/etc/quadstor.conf will create new vcartridges with size of 8 GB

The MaxVCartSize can range from 1 to 1600. If MaxVCartSize is specified it takes precedence over the predetermined size based on the vcartridge type. MaxVCartSize is checked for before creating a vcartridge. Therefore there is no need to restart the quadstor service after adding/modifying this value

NOTE: A backup application may estimate the available capacity based on the cartridge type.

VCartridge Locations

In the figure shown above there are two columns 'Element' and 'Address' which describe the location of a VCartridge in the VTL

'Import/Export' under the 'Element' column indicates that the VCartridge is placed in a 'Import/Export' element (mail slot)

'Slot' indicates that the VCartridge is placed in a storage slot and 'Drive' will indicate that it is placed in a tape drive

By default a new VCartridge is placed in a free storage slots. If there are no empty storage slots then it is placed in a free import/export element. This behavior can be changed to first add a new VCartridge into any available import/export element first by adding the following line to /quadstorvtl/etc/quadstor.conf

Virtual Tape Library Solutions

Virtual tape library free

A quadstorvtl service restart is not required when changing the above property. Each time a VCartridge is added the value of this property is checked

Exporting a VCartridge

1. In the backup application move the VCartridge to a free Import/Export element

The VCartridge is removed from the active list of vcartriges for the VTL and is moved to a virtual vault. An inventory of the VTL by the application will no longer list the VCartridge. The status of the vcartridge will show as 'Vaulted'

Unvaulting an exported VCartridge

Once a VCartridge has been exported, to move into back into the VTL, click on the 'Unvault' link. Unvaulting a vcartridge will fail if there are no available free storage or import/export slots

Command line configuration

Display VTL emulation type codes

Every medium changer device and tape drive emulated has a type code assigned by the system. /quadstorvtl/bin/vtconfig –h displays the type code assigned and is as shown below

Adding a VTL

In the above command type and drive type will be the library and drive type codes. Slot count is optional and if slot count is zero or not specified, the system will calculate the number of slots based on the drive type and the available space in the storage pool. The default drive start address of 1 and slot start address of 2 will be used if these values are not specified.

Deleting a VTL

Enabling deduplication

Disabling deduplication

Vcartridge Configuration

Vcartridge emulation type codes

Adding a vcartridge

Deleting a vcartridge

Enable WORM

Virtual Tape Library Aws

Disable WORM

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Unvault a vcartridge

Load (mount) a vcartridge

Virtual Tape Library Solutions

Unload (unmount) a vcartridge