Virtual TapeServer 8.0 Supplemental Installation Guide

20 | Enabling and Configuring AutoCopy and Instant DR
Overview of Instant DR
Instant DR enables you to create and maintain identical copies of backup data on VTS disk
storage at one or more locations. Virtual tapes are transmitted from one vault to another. The
Instant DR jobs indicate the pools or virtual tapes to be transmitted. When a job is initiated, a
copy of the virtual tape is transmitted over the network link. Be aware that the virtual tapes
duplicated on a remote vault consume additional disk space, which is the same amount as the
original virtual tape.
VTS servers cannot “see” each others’ pools and virtual tapes until the Instant DR jobs run.
The pools and virtual tapes in the primary operation page look identical if all virtual tapes are
copied. If selected virtual tapes are copied using the Instant DR job, the virtual tape and pool
lists are different. Automatic Event Management Service (EMS) mounting chooses from pools
as it would in day-to-day operations because the virtual tapes will be created in the new vault.
Note An Instant DR job will fail if the virtual tape already exists in another pool on the
target. Virtual tape names must be unique across all vaults and pools.
If an encrypted virtual tape is stored on an Instant DR server and the Instant DR server
attempts to perform an operation on the tape, Data Encryption must be enabled and the key
server that was used to encrypt the tape must be configured on the Instant DR server. If not,
the tape operation will fail and an error message is displayed on the Instant DR server
indicating that the operation failed. Refer to the Virtual TapeServer Configuration Guide for
information about Data Encryption and an explanation of the possible failures.
In general, Instant DR should be used if files do not change much from day to day. Data is
transmitted in batches, one or more times per day, and only data differences are sent.
Bandwidth is consumed when the data transmission is scheduled according to policy, usually
during off-peak hours. Instant DR is supported across multiple sites, from one to many
servers based on the configuration.
Instant DR performs well in environments where the backup data does not significantly
change on a daily basis. Synchronizing transaction files, which can change constantly, is not
necessary a good use of Instant DR. Poor performance may result when synchronizing
transaction files because the process by which Instant DR computes file differences can take
longer than copying an entire file. You may also rely on AutoCopy for synchronizing data. See
Overview of AutoCopy below to determine if AutoCopy is a better solution for your needs.
If Instant DR is licensed, you must enable licensing by entering the license key as described in
the Virtual TapeServer Configuration Guide. Then, you can create new Instant DR backup
schemes as well as launch and monitor the remote synchronization processes. You can also
automate Instant DR backups using the VTSPolicy command, if EMS communication is
configured (see
Configuring EMS Communication on page 51). This chapter describes how to
perform these tasks.
Overview of AutoCopy
AutoCopy enables you to copy a virtual tape from one VTS server to another when the virtual
tape is mounted, modified, and dismounted by the host server. Configure AutoCopy to set the
following:
• The pools to be monitored for mount and dismount activity on the VTS system
• The VTS system that will be the recipient of copies of modified virtual tapes
• The pool name on the target and recipient VTS system