A tape storage is a target where media can be added, removed, and moved between multiple targets. The term removable media is used to specify various types of removable media supported by Commvault® software, including tape and USB disk drives, which can be moved between MediaAgents for data protection and recovery operations.
Tape storage best practices:
Configure the tape storage cleaning method to use. Software cleaning (Commvault) or hardware cleaning (tape unit) can be used, but not both. A choice must be made.
Share the tape storage if required.
Create a barcode pattern for cleaning tapes and assign it to the Cleaning Media group (CommCell® Console).
If using multiple scratch media groups, create scratch groups and barcode patterns to use (CommCell® Console).
Validate drive speed (from the CommCell® Console) and document for future reference.
Tape Storage Types
Commvault software supports the drives for the following tape storage:
Standalone
A standalone tape drive has no robotic media changer and no internal storage slots. Multiple standalone drives controlled by the same MediaAgent can be pooled together to support multi-stream jobs or cascade of a single stream job without having to respond to media handling requests. Media used by a Standalone tape target can be pre-stamped or new, and will be prompted for, by backup or restore jobs as necessary.
Blind
A 'blind' tape target has no barcode reader and is supported by the Commvault® software maintaining the map/inventory externally in the CommServe® server metadata.
Dedicated
A static configuration where the drives and media changer are connected to only one MediaAgent.
Static Shared
A static configuration where the drives and media changer are connected to only one of several MediaAgent hosts.
Example: In a target with four tape drives, one MediaAgent may have control of the media changer and two drives within the target while another MediaAgent may have control over the other two tape drives. A drive connected to one MediaAgent host is not accessible from the other MediaAgent hosts. Should the MediaAgent component having media changer control fail, no further loading/unloading of media can occur until that MediaAgent is active again. Shared tape storage in today's world of Storage Area Networks (SAN) are not common.
Dynamic Shared
In a Dynamic Shared tape storage, the drives and media changer are on a SAN and can be accessed by multiple MediaAgent hosts. Drives not being used by one MediaAgent can be assigned to and used by another MediaAgent. If the MediaAgent with control of the media changer fails, the control can be automatically passed to another MediaAgent. The primary advantage of a Dynamic Drive tape target is the use of multiple MediaAgents for processing reads/writes. Dynamic Drive capability is referred to as GridStor® Technology. GridStor technology is an option that enables load balancing and failover of data protection jobs.
Virtual Tape Library (VTL)
A Virtual Tape Library (VTL) is a disk-based target that emulates the traditional tape devices and formats, and can be installed onto any disk space. Refer to the manufacturer's documentation to see if a disk-based storage subsystem supports VTL emulation mode. Follow the manufacturer's instructions to create the virtual tape library and make sure that the MediaAgent can detect the virtual arm changer and the drives created.
USB Devices - PnP (Plug and Play) Disk Libraries
For some environments with remote office locations connected to a main data center with limited bandwidth such as 'fractional T1' or 'satellite,' USB backup devices may provide the best protection solution. PnP (Plug and Play) Disk Libraries (USB devices) are configured and recognized by Commvault® software as standalone tape devices. This allows data to be protected to USB devices using MediaAgents at remote locations, removed and sent to another location and connected to a different MediaAgent where the data can be accessed and restored. Since the USB device is detected as a tape device it is considered portable and any Windows MediaAgent within the CommCell® environment can recognize the device and access/restore the data. This method can also be used for seeding stores when using Commvault deduplication for remote office protection.
