Setup guide

Each partition managed by the Bandwidth Manager must have a [Device] section associated to it in the
/usr/discreet/sw/cfg/sw_bwmgr.cfg file.
To add a new device to the Bandwidth Manager:
1 Open the /usr/discreet/sw/cfg/sw_bwmgr.cfg file in a text editor.
2 Add a new [Device] section at the end of the file, using the following syntax:
TIP You may also copy and paste an existing [Device] section, and change its parameters.
[Device<device_number>]
Path<path_number>=<device_mount_point>
TotalAvailableReadBandwidth=<total_read_bandwidth>
TotalAvailableWriteBandwidth=<total_write_bandwidth>
DefaultReservation=<default_reservation>
where:
■ <device_number> represents the number of the [Device] section, starting at 0. For example:
[Device0]
■ Path specifies the partition's mount point. Since a partition can have several paths, <path_number>
represents the number of the current path, starting at 0 for each device. For example:
Path0=/mnt/XYZ
Path1=/usr/local/ABC
■ TotalAvailableReadBandwidth represents the estimated total reading bandwidth of the device, in
megabytes per second. Based on this value, and on the amount of active reservations for the current
partition, the Bandwidth Manager decides whether new reservation requests are granted or rejected.
For example:
TotalAvailableReadBandwidth=200
■ TotalAvailableWriteBandwidth represents the maximum estimated writing bandwidth of the
device, in megabytes per second. If this parameter is not specified, its value defaults to the value of
TotalAvailableReadBandwidth. For example:
TotalAvailableWriteBandwidth=150
NOTE The total bandwidth parameters are estimates of the theoretical maximum bandwidth of the
partition. The actual bandwidth is affected by several factors, including multiple applications trying to
concurrently read or write to it. The Bandwidth Manager continuously measures partition performance
and dynamically maintains the actual total available bandwidth for each partition.
■ DefaultReservation sets the bandwidth assigned by default to applications that are denied a
reservation request or that don't have individual or group reservations associated to them. The
value is expressed in megabytes per second. For example:
DefaultReservation=10
3 After setting up all the partition parameters described above, you can start defining reservations for
the current partition.
4 Save and close the configuration file, and restart Stone and Wire by typing:
/etc/init.d/stone+wire restart
66 | Chapter 6 Software configuration