# xSQL filebackup

> Perform a file backup for a persistent database.

> ### For an overview see page File_Backup

> ### Prototype

>         XSQL>filebackup dbFile logFile [nThreads]

> ### Arguments

> dbFile | The path and filename for the backup database file
> logFile | The path and filename for the backup log file
> nThreads | The number of threads to perform the file copy operation

> ### Description

> > This command copies the database and log file for a persistent database. The database can then be "restored" by simply specifying these backup files when opening the database in the normal way.

> > > Note that the SQL file backup temporarily prevents the truncation of the database log file, then copies the database and log files using one or more threads. Note the following:

> > > > 1. The database can be changed while the file backup is in progress

> > > > 2. The file backup method only works with REDO logging policy and will return an error if using UNDO log or if there is no transaction log

> > > > 3. The SQL file backup does not support either multi-storage or mfd databases. The backup process makes copies only of a single database and log files passed into the API

> > > The advantage of using this backup method over the Incremental backup is that it could be faster and no restore procedures are necessary; applications simply open the backup database.

> > > The ``file_backup_delay`` config file parameter can be adjusted to specify the delay in milliseconds between writing backup blocks in order to minimize backup impact on performance.

> > (See also C API mco_disk_backup().)

> ### Example

>         XSQL>filebackup SimpleDb_backup.dbs SimpleDb_backup.log 1