File system connector backups
If you use the default file system connector option, make sure that you direct your backups to one or more file systems that are large enough to hold your database backups. Also, the file systems must be accessible over reliable, fast, network connections to the system.
You can specify up to 16 file system locations for your backups. The backup process uses the specified destinations concurrently to save the data by using one stream for each destination. The backup process saves the metadata in one location, but it saves the data across the specified locations.
If the backup process encounters the file-size limit of a backup destination, it automatically splits the table file that it is writing into multiple files to avoid the limit without loss of data. The backup process writes table files in 1 TB “portions” by default. The limit is user-configured by using the registry setting host.bnrFileSizeLimitGB.
If one of the destinations fills and has no free disk space, the backup process automatically suspends write activity to that location and continues writing to the other destinations without loss of data.
If you configure the destinations on unique disk devices that each offer good performance and bandwidth, the database backups typically take less time to complete than when you save the backup to only one of those file system locations. It is important to choose your destinations carefully. For example, if you choose two file system locations that are on the same disk, there is no performance gain because the same disk device is writing the backup data. Also, differences in the write-rate of each file system destination can result in varying completion times.
You can specify the list of locations by using the nzbackup -dir option, or you can create a text file of the locations and specify it in the nzbackup -dirfile command.
Similarly, when you restore backups that are saved on file systems, you specify the locations where the backups are by using the nzrestore -dir option. Or you can create a text file of the locations and specify it in the nzrestore -dirfile command. The restore can also be a multi-stream process to improve the performance and time to restore.