VSS & SQL Writer Service Questions

• Harold Buckner

  SSCarpal Tunnel

  Points: 4175

  More actions

  January 13, 2010 at 6:32 am

  #137484

  I have a couple of questions that I'm tring to get answered but keep going around in a circle.

  We just move a small application server with SQL server 2005 into VMWare. I noticed in the SQL Logs that whenever the VM takes a snap shot it calles on the Volume Shadow Copy Service which then calls on the SQL Writer.

  According to the SQL log...

  IO is frozen on the databases and a backup is performed.

  IO is then resummed on the databases

  A database backup log entry is created.

  Example.

  Date1/13/2010 6:24:54 AM

  LogSQL Server (Current - 1/13/2010 8:02:00 AM)

  SourceBackup

  Message

  Database backed up. Database: model, creation date(time): 2000/08/06(01:40:52), pages dumped: 1, first LSN: 52:488:1, last LSN: 52:490:1, number of dump devices: 1, device information: (FILE=1, TYPE=VIRTUAL_DEVICE: {'{44916A2E-9895-44E0-8082-BBB11D3CBE82}1'}). This is an informational message only. No user action is required.

  My questions are:

  Are these backups using the with copy_only option, I can't find anything on it with the exception that the application vender can specify different options?

  Does these backups effect my Log Sequence Numbers?

  To ensure my recovery scheme was not effected by this backup, I restored my backup and all my log backups that were done before the VSS snapshot and the log backups after the VSS snapshot. So it looks to me everything is correct but wanted to get verification. I contacted the VMWare and did not get a answer.

  Does any one else have experience in this and knows the answer.

  Thanks

  Harold