Red Gate Virtual Restore Scripting (Part 10)
If you have been following along since December, then you know that I have been doing some investigation with the Red Gate Backup and Restore bundle to implement in our system with our use of Ola Hallengren’s backup maintenance scripts. One of our last stumbling blocks has been automating and scripting of the Red Gate Virtual Restore product. We have moved methodically through the list and with the help of Red Gate’s excellent support department resolved each item including this one.
The problem we had been that when we tried to verify the backup through restoration and DBCC CHECKDB on a certain database, that was considerably larger than all of the other databases on this server, we would not have enough space on the drive using our restore script we created last week. That scripting solution is great as long as there is enough space on the drives to attach the database files from backup and then drop them.
The beauty of the Virtual Restore product, in case you did not already know, is that it can restore these files with a much smaller footprint than the actual database files take up in the exiting format. However, the problem is that it is strictly a wizard at this point that will grab a specific backup and run the restore manually and then drop it once it checks the integrity and consistency. This is a great product but this is feature should be included or else it does not help much especially when you have hundreds of databases.
We ran the wizard and then viewed the script:
RESTORE DATABASE [TestDB_Virtual] FROM
WITH MOVE N’TestDB_Data’ TO N’F:\VirtualRestore\TestDB_Data_TestDB_Virtual.vmdf’,
MOVE N’TestDB_Index’ TO N’F:\VirtualRestore\TestDB_idx_TestDB_Virtual.vmdf’,
MOVE N’TestDB_Log’ TO N’F:\VirtualRestore\TestDB_Log_TestDB_Virtual.vldf’, NORECOVERY, STATS=1,REPLACE
RESTORE DATABASE [TestDB_Virtual] WITH RECOVERY, RESTRICTED_USER
DBCC CHECKDB ([TestDB_Virtual])
DROP DATABASE [TestDB_Virtual]
This script did not work when we ran it via T-SQL because of a lack of disk space which is the same problem we encountered using the Backup Pro restore script, however it did work with the Red Gate Virtual Restore Wizard. We contacted support to find out why there was a difference on the same box. Basically SQL Server does not know that the HyperBac service is running in the background. The wizard is smart enough to check your disk space and if you do not have enough it temporarily adds an entry into the HyperBac configuration that tricks SQL Server into thinking that you have the right amount of disk space in order to complete the task.
The parameter is “VirtualDiskSize=” where the value is an integer to represent the disk size in megabytes. You add the parameter to the bottom of the to the hyper.conf file found in the C:\Program Files (x86)\Red Gate\HyperBac\Bin folder. At this point then you restart the HyperBac service and the problem is solved! Next I will try to automate this script….stay tuned!