How To:Split DLEs With Exclude Lists
This article describes a way to split your DLEs to produce smaller individual dumps. This is often useful when you only have a few DLEs, and one of them is much larger than the rest: without this technique, the tape usage spikes when Amanda runs a level 0 for that DLE. For example, many small businesses have one very large NFS-mounted /home. Using this technique, /home can be split by subdirectory, e.g., /home/[a-o]* and /home/[p-q]*.
If you have a lot of large dumps, then tape spanning may be more useful.
You have to use GNU-tar in your dumptypes for this.
Try to redefine your disklist as in the following example:
fatboy /bigmama_BIGDIR /bigmama { # a big subdirectory
comp-user-tar
include "./bigdir"
}
fatboy /bigmama_FILES01 /bigmama { # all files beginning with...
nocomp-user-tar
include "./file[01]*"
}
fatboy /bigmama_FILES23 /bigmama {
nocomp-user-tar
include "./file[23]*"
}
...
fatboy /bigmama_REST /bigmama { # Catch-all
nocomp-user-tar
exclude "./file[0-9]*"
exclude append "./bigdir"
}
(example taken from a mail by Paul Bijnens on the Amanda-users-list)
The trick is to form several chunks of data of which each fits on tape. In the example above the chunks are formed by regular expressions matching files named like file00, file123 and file9999. You have to look at your DLEs to find the patterns describing your chunks.
As this technique forms data-chunks that fit on your tape it also helps Amanda to schedule your backups more flexible. Having more and smaller DLEs, the planner has more variations to possibly schedule your backups, so this will help getting nice output from amadmin <conf> balance, too.