Introduction › CA Vtape Features

CA Vtape Features

Using CA Vtape, you can create a virtual tape environment from any combination of mainframe disk and tape hardware, including resources you already own. You can add or upgrade resources as needed to take advantage of advancements in capacity and performance, regardless of manufacturer. Since CA Vtape is software, you can scale your installation by one virtual device or by one DASD volume without the high incremental costs of a hardware solution.

CA Vtape is an automated virtual tape system or server that provides you with the following capabilities and benefits:

• It allows you to greatly reduce costs by using Virtual Devices in place of real ones, which:
  • Helps to reduce the need for new tape hardware
  • Reclaims valuable floor space
  • Helps save energy
• It fully automates tape stacking, which:
  • Reduces wasted capacity on each cartridge
  • Helps you more efficiently use robotic tape hardware

Virtual Tape Drives are simulated within the operating system using address spaces, data spaces, and VSAM linear data sets. These Virtual Tape Drives use Virtual Volumes, which are simulated by allocating data sets on DASD. Collectively, these data sets act as a large Virtual Volume DASD buffer or cache.

The Virtual Volume DASD buffer is completely managed by CA Vtape. When a Virtual Volume is mounted, its data sets are allocated and accessed on DASD using high-performance data access methods. At dismount, modified Virtual Volumes are queued for stacking onto tape cartridges. After being copied to tape, the DASD space is marked as reusable for other Virtual Volumes.

Until a Virtual Volume's DASD space is reused, a mount for the Virtual Volume can typically occur almost immediately. Once its DASD space has been reused, a mount for a Virtual Volume will trigger an automatic recall from its stacked location on tape.

A least recently used (LRU) algorithm is used to manage DASD space occupied by Virtual Volumes. Virtual Volumes that are not remounted have their DASD space reused before Virtual Volumes that are remounted. This minimizes mount delays due to tape recalls.

Recall performance is generally equal to or better than native tape performance. Because CA Vtape recalls the entire Virtual Volume, subsequent access to any data set on the Virtual Volume occurs without having to perform another recall.

Each Virtual Volume is assigned to a stacking group based on the first data set written to the volume. Each stacking group is broken down into three subgroups by customizable retention periods.

How the stacking groups are used is completely customizable. Groups can be used to stack:

• By expiration date
• By location
• By a forced separation requirement such as that required by paired log or transaction data sets
• By application
• By classification of the data (for example; production, test, system, or disaster recovery)
• With an optional duplex copy to be used for Disaster Recovery or local recovery if a physical cartridge is lost or damaged
• With an optional export copy to send user-format tapes to sites not using CA Vtape

This intelligent stacking function allows you to group your data so you can assign the appropriate amount of system resources to managing its vaulting and recovery.

When the stacking function should be active is also customizable. You can decide to:

• Let CA Vtape decide
• Set up customizable cache thresholds
• Set up customizable time periods
• Perform it manually
• Combine the above