Error: not enough space even though plenty is available

brianacraig

I've got SQL Backup running nightly full backups on all of the databases in my development server. All of the databases are set to be backed up to an external drive that has 400GB free, and none of the backups are more than 4GB compressed.

That said, all of the databases with a raw size over about 10GB are failing with a "There is not enough space on the disk" error message. The databases under 10GB raw size are being backed up just fine. Does SQL Backup maybe stage the backup to disk on a drive other than the destination drive, and that's what would be causing this error?

Here's a sample error message from one of the databases that fails.

8/19/2009 4:54:40 AM: BACKUP DATABASE [MyDatabaseName]  TO VIRTUAL_DEVICE = 'SQLBACKUP_AB2E77A3-BB08-448D-BAA9-2D7B836B195C' WITH BUFFERCOUNT = 6, BLOCKSIZE = 65536, MAXTRANSFERSIZE = 1048576, NAME = N'Database (MyDatabaseName), 8/19/2009 4:54:39 AM', DESCRIPTION = N'Backup on 8/19/2009 4:54:39 AM  Server: BENGAL\DEV05  Database: MyDatabaseName', FORMAT

8/19/2009 5:00:39 AM: Thread 0 error: 
Error 620: Error writing to backup file(s).
Process terminated unexpectedly. Error code: -2139684860
8/19/2009 5:00:39 AM: Warning 210: Thread 0 warning: 
Warning 210: Error writing to backup file:  K:\Databases\DEV05\FULL_DEV05_MyDatabaseName_20090819_045439.sqb
Warning: System error 112 (There is not enough space on the disk)
8/19/2009 5:00:39 AM: 
SQL error 3013: SQL error 3013: BACKUP DATABASE is terminating abnormally.
SQL error 3271: SQL error 3271: A nonrecoverable I/O error occurred on file "SQLBACKUP_AB2E77A3-BB08-448D-BAA9-2D7B836B195C:" 995(The I/O operation has been aborted because of either a thread exit or an application request.).
SQL error 3202: SQL error 3202: Write on "SQLBACKUP_AB2E77A3-BB08-448D-BAA9-2D7B836B195C" failed: 1117(The request could not be performed because of an I/O device error.)

Thanks for your help!
Brian

Chris.Allen

Hi, thanks for the error report. I think that what could be happening is that there is not enough free contiguous memory available to use as buffer space for SQL Backup. This memory exists in SQL Server's MemToLeave area and is a fixed amount (128MB by default).

SQL Backup requires 6*MAXTRANSFERSIZE per thread, so reducing the number of threads or lowering the MAXTRANSFERSIZE value in the script may help. You may use the MAXTRANSFERSIZE keyword in the backup command. The value must be in 64KB multiples (65536) for instance, MAXTRANSFERSIZE=524288. Here is an article describing the SQL Server memory issue in more detail:

http://www.red-gate.com/supportcenter/C ... 000142.htm

Hope this helps!