SQL Server Snapshot backup and restores - Part 1

 

Recently, I was working with one of my customers to help them design their backup scheme. This customer has their IT team very comfortable with their SAN infrastructure. Their current infrastructure and backup solution for non-Microsoft product stack is all based on SAN.

The way they work is they mirror their disks (or volumes) to other disks. Once mirror is in Sync, they break the mirror, mount the mirrored disk on to another server and take file system level backups. They call it as BCV copy.

This customer was interested to know if he could do the same with Windows/SQL.

As it sounds independent of the OS/DB, customer gave it a shot. It worked. They were able to make their BCVs to tape without a problem. (Disk Mirror -> Sync -> Break Mirror -> mount it on new server -> take tape backup).

Now, no backup test is complete without a restore. So they tried to restore. It worked as expected as well. However, there was a issue which needed to be addressed.

Customer couldn’t restore BCV data files and then apply additional transaction log files to bring database up to date. Why? As soon as you attach these BCV’ed files, SQL will recover them and database will be operational.

In comes SQL Server VDI (Virtual Device Interface).

Next : What I did to SQL Server VDI Samples to facilitate subsequent transaction log restores. Stay tuned for more.

Meanwhile see these articles for more knowledge.

A Guide for SQL Server Backup Application Vendors

How It Works: SQL Server - VDI (VSS) Backup Resources

Comments

• Anonymous
  April 22, 2014
  Can we do TLOG restore after BCV restored? My guess is no.