NEC Storage ReplicationControl SQL Option, User Manual

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Chapter 4 Functions of NEC Storage ReplicationControl SQL Option
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Chapter 4 Functions of NEC Storage
ReplicationControl SQL Option
This chapter explains the its operational outline, command operation methods, display of various states, as well as
some notes on the metafile management of the snapshot backup that is a function of the NEC Storage
ReplicationControl SQL Option operating on the business server.
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Snapshot backup refers to a function that performs snapshot backup and restoration without suspending
the database by using the functions provided by Microsoft SQL Server 2000 and NEC Storage series
data replication.
The snapshot backup minimizes or eliminates the need for using the server’s resource for backup
purposes.
The snapshot backup is conducted by the following functions:
•
I/O freeze function
Freezes the update I/O of Microsoft SQL Server 2000 to specify the static point of the database
during the snapshot backup.
•
Creation of metafile
Refers to the file for storing Microsoft SQL Server 2000’s file configuration and transaction log
state information, etc. The file is created during snapshot backup and the information is used for
snapshot restoration.
•
Data Replication operation
Separates or connects MVs and RVs of NEC Storage by using the functions of NEC Storage
ReplicationControl.
Moreover, if the update I/O for the backup target database is attempted during the snapshot backup, the
Microsoft SQL Server 2000 freezes the update I/O for all databases included in the instance in which
the backup target database is located. Ending the snapshot backup will automatically release the
control of the update I/O for all databases and resume the update I/O function.