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BACKUP LOG cannot be performed because there is no current database backup.

Hi,

Im currently trying to create a job to backup our transaction logs on an hourly bases. When I use the following command: -

BACKUP LOG [testdata] TO DISK = N'G:\testdata.trn';

It comes up with the following message: -

BACKUP LOG cannot be performed because there is no current database backup

The current backup strategy is a full backup everynight at midnight using the following commands in a job: -

-- database backup file manipulation
EXEC master..xp_cmdshell 'del Z:\MSSQL\BACKUP\ONE_DAY_OLD\testdata_old.bak /Q';      -- delete old copy of backup
EXEC master..xp_cmdshell 'copy Z:\MSSQL\BACKUP\DAILY\testdata.bak Z:\MSSQL\BACKUP\ONE_DAY_OLD\testdata_old.bak'; -- copy last night's backup to ONE_DAY_OLD
EXEC master..xp_cmdshell 'del Z:\MSSQL\BACKUP\DAILY\testdata.bak /Q';      -- delete current copy of backup

-- log file manipulation
EXEC master..xp_cmdshell 'del Z:\MSSQL\BACKUP\ONE_DAY_OLD\testdata_old.trn /Q';      -- delete old copy of backup
EXEC master..xp_cmdshell 'copy Z:\MSSQL\BACKUP\DAILY\testdata.trn Z:\MSSQL\BACKUP\ONE_DAY_OLD\testdata_old.trn'; -- copy last night's backup to ONE_DAY_OLD
EXEC master..xp_cmdshell 'del Z:\MSSQL\BACKUP\DAILY\testdata.trn /Q';      -- delete current copy of backup

BACKUP DATABASE [testdata] TO DISK = N'Z:\MSSQL\BACKUP\DAILY\testdata.bak' WITH NOINIT , NOUNLOAD , NAME = N'testdata_daily', NOSKIP , STATS = 10, NOZORMAT
BACKUP LOG [testdata] TO DISK = N'Z:\MSSQL\BACKUP\DAILY\testdata.trn';

backup log [testdata] with truncate_only;

dbcc shrinkfile(testdata_log,0);

Am I right in saying that if you use backup log [testdata] with truncate_only; it breaks the backup chain and hence I am getting this message? Also that the shrinkfile command will commit the transactions of the log into the main database file?

Many Thanks
Lee

Raja Jegan R

Kindly take a Full Backup and then try doing your Log Backup.

BACKUP LOG [testdata] TO DISK = N'G:\testdata.trn';

And after that have regular Transactional Log Backups with reduced time intervals as of now.

http://msdn.microsoft.com/en-us/library/aa173551(SQL.80).aspx

Hope this helps

Raja Jegan R

>> Am I right in saying that if you use backup log [testdata] with truncate_only; it breaks the backup chain

Depends upon situation.
1. Using TRUNCATE_ONLY breaks the Backup chain if you do it before your Full Backup or Differential Backup.
2. Using TRUNCATE_ONLY breaks the Backup chain if you do it after your Full Backup or Differential Backup.

>> and hence I am getting this message?

No..

>> Also that the shrinkfile command will commit the transactions of the log into the main database file?

It will Discard the uncommitted transactions and it Wont commit.

Raja Jegan R

The error you mentioned "BACKUP LOG cannot be performed because there is no current database backup" will happen:

When you change the database to simple to truncate the log, then back to full recovery. You have to do a manual full backup before you can do a log back up again.

Hence do a Full Backup manually now as mentioned earlier and this would solve this problem

ljhodgett

ASKER

Hi,

Sorry the database is set as full recovery model.

I've run the following on the development server: -

BACKUP DATABASE [testdata] TO DISK = N'C:\testdata.bak' WITH NOINIT , NOUNLOAD , NAME = N'testdata_daily', NOSKIP , STATS = 10, NOFORMAT
BACKUP LOG [testdata] TO DISK = N'C:\testdata.trn';

and it completes sucessfully. I can backup the transaction logs everytime afterwards using : -

BACKUP LOG [testdata] TO DISK = N'C:\testdata.trn';

As soon as I do the following it comes up with the error messages when trying to backup the transaction logs: -

backup log [testdata] with truncate_only;

dbcc shrinkfile(testdata_Log,0);

Best Regards
Lee

ljhodgett

ASKER

Hi,

I've found that the following command once executed give me the error message: -

backup log [testdata] with truncate_only;

Is this line strickly necessary?

Many Thanks
Lee

ASKER CERTIFIED SOLUTION

Raja Jegan R

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