How to reduce the backup impact on an Amanda client when performing multiple dumps on the same client

This article is for Amanda Enterprise (AE)

Amanda can be used to backup multiple filesystems from an Amanda client. If maxdumps parameter is configured in the amanda.conf file to a value greater than one, Amanda will try do backups for multiple DLEs (filesystems) from an Amanda client at the same time. This can increase the load on the Amanda client.

Amanda provides spindle numbers as part of the disklist.conf configuration file. If the two disk list entries have the same spindle number, they will not backed up in parallel. Amanda will start the backup of one DLE first and backup the second DLE with same spindle number after the first one finishes. Spindle numbers can be used to reduce read I/O contention and balance the backups on the Amanda client.

Spindle numbers in DLEs are considered only if the maxdumps parameter has a value greater than 1.

Example:

Disklist entries for an Amanda client using the same disk for the /home mount point and a different disk for the /usr mount point.

amandaclient.company.com "/home/userA" "/home/userA" 1
amandaclient.company.com "/home/userB" "/home/userB" 1
amandaclient.company.com "/usr" "/usr" 2