Restore LDF file after restoring backups in SQL Server 2005?

Restore LDF file after restoring backups in SQL Server 2005?

am 22.08.2007 10:34:28 von Victor Engmark

I'm working on a restore procedure for the case where all MDF files
are missing, but the LDF files are all intact. A full backup is done
every 24 hours, and a log backup is done every 3 hours. After
restoring the last full + log backups, is it at all possible to use
the LDF files to recover data from that point up to a newer point in
time?

I've found a post which explains how to do this on SQL Server 2000
browse_thread/thread/3ef5c7cbc0a83334/f3b0c70811d35ed7>, but step 4
fails with the following error message:
BACKUP LOG cannot be performed because there is no current database
backup.

Re: Restore LDF file after restoring backups in SQL Server 2005?

am 22.08.2007 12:38:44 von Erland Sommarskog

l0b0 (victor.engmark@gmail.com) writes:
> I'm working on a restore procedure for the case where all MDF files
> are missing, but the LDF files are all intact. A full backup is done
> every 24 hours, and a log backup is done every 3 hours. After
> restoring the last full + log backups, is it at all possible to use
> the LDF files to recover data from that point up to a newer point in
> time?

At that point it may be a little late. Say that disaster strikes and
your MDF file is dead. At this point you can perform BACKUP LOG WITH
NO_TRUNCATE to back up the log. Then you restore and apply all logs
including this one.

> I've found a post which explains how to do this on SQL Server 2000
> > browse_thread/thread/3ef5c7cbc0a83334/f3b0c70811d35ed7>, but step 4
> fails with the following error message:
> BACKUP LOG cannot be performed because there is no current database
> backup.

It seems that Dan left out one point his post. And which point is fairly
obvious: you need to take a full backup of the newly created dummy database.
Since Dan read this group regularly, I hope is able to step in and clarify.



--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downlo ads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books .mspx

Re: Restore LDF file after restoring backups in SQL Server 2005?

am 04.09.2007 15:55:12 von Victor Engmark

On Aug 22, 12:38 pm, Erland Sommarskog wrote:
> l0b0 (victor.engm...@gmail.com) writes:
> > I'm working on a restore procedure for the case where all MDF files
> > are missing, but the LDF files are all intact. A full backup is done
> > every 24 hours, and a log backup is done every 3 hours. After
> > restoring the last full + log backups, is it at all possible to use
> > the LDF files to recover data from that point up to a newer point in
> > time?
>
> At that point it may be a little late. Say that disaster strikes and
> your MDF file is dead. At this point you can perform BACKUP LOG WITH
> NO_TRUNCATE to back up the log. Then you restore and apply all logs
> including this one.

Thanks! I ended up doing the following:
1. BACKUP LOG database TO DISK = 'C:\database.bak' WITH NO_TRUNCATE;
2. Restore full + log backups without recovery
3. RESTORE LOG database FROM DISK='C:\database.bak' WITH MOVE
'database_log' TO 'L:\database_log.LDF', RECOVERY;

It works fine.