Filter
Top Products
Chapter 3 Notes
74
Usual file
As basic operations, first temporarily halt the operations on the MV and flush the MV cache data
using the command provided by replication operation. Then, unmount the MV to release
association between the file system and disks. At this time, when the MV is used from another
operation or service, an unmounting error occurs.
If unmounting error occurred due to referencing or access from unexpected product, writing
process is completed after waiting for completion of delayed updating process, in several tens of
seconds. If Separate is executed without writing cache data completely, files on the RV may
lack file consistency. In such a case, executing CHKDSK command upon mounting RV on
backup server restores inconsistent files.
For planning backup operations, extract processes and services to be halted. Against
unmounting errors, processes to wait for delayed updating must be considered.
Oracle
Combination of the Oracle standard on-line backup function and the data replication function
allows producing backup data even under business operation. The on-line backup reserves a
logical static point in combination with log. The log is used upon recovery.
For executing cold backup or using data replication for files other than database requires
considerations similar to those for usual files.
Microsoft SQL Server 2000
Use of the ReplicationControl SQL Option allows producing backup data even under business
operation. Refer to the “ReplicationControl SQL Option User’s Manual” for details. In the
cases above also, backup of transaction logs is made via network. Using data replication for
transaction log requires considerations similar to those for usual files.
Halting database and making backup physically requires considerations similar to those for usual
files. The backup data made in such process cannot be used for transaction log.
(2) Replicate and Data Consistency
When using RV file on backup server and replicating data again, cache data on backup server
must be discarded.
To discard cache data, flush the cache data and unmount the RV using the commands provided by
replication operation. You can use the -force option to forcibly unmount the RV even when the
file system is being used.
If the process above is omitted, inconsistency may occur between cache and volume upon
separating again, which may result in destruction of file system.