Specifications

6 MDR User Guide
1.6 MDR Preloaded Software (MDR Firmware)
The most significant software module in the MDR system is the MDR Server. The
MDR Server processes all accesses to the disk array (except Direct Connection). The
key configuration files used by the MDR Server are listed here.
• mmon.ini – must be present to run the MDR, seldom changes
• vxbsp.ini – user may need to edit this file to modify parameters
• vxbp.txt – contains VxWorks boot parameters. User will only edit when chang-
ing boot method (i.e., standalone, shared memory, Ethernet)
• mdr.ini – used to pass information about the physical configuration and options
(i.e., MDR model, disk info, DPIO and FC parameters)
The MDR Shell is the user process used to request services from the MDR Server. Note
that the disk group function (i.e., named groups) is not available when running the MDR
Shell on the MDR board (available only in MDR on Host).
1.7 Data Storage Format
MDR relies on arrays of commercial disk drives as the permanent storage medium, and
the very high recording performance is obtained by striping (interleaving) data across
multiple disks. The typical storage system of an MDR has a storage capacity that ranges
from tens of Gigabytes up to Terabytes, with disks configured as cost-effective JBOD
(Just a Bunch Of Disks) units or as complete integrated RAID (Redundant Arrays of In-
dependent Disks) units with built-in redundancy.
The disk units are connected to MDR with Fibre Channel Arbitrated Loop (FC-AL) op-
erating at 1.062 Gbit/sec, using the SCSI protocol and command set to communicate
with the disk system. Up to 125 disks units may be connected to the same physical loop.
MDR supports Fibre Channel both with fiber optic or differential twinax copper cables,
and hubs and switches can be incorporated in the storage system to obtain convenient
cabling, easy reconfiguration, maximum flexibility and scalability.
The MDR storage system is organized as a block device: a block device divides the stor-
age medium into a number of blocks, where a unique number addresses each block. The
storage system is typically much larger than each recording, therefore the MDR imple-
ments functionality for storing up to 248 recordings. Each recording must be given the
following attributes:
• Name
• Block number identifying the start of the recording
• Number of blocks specifying the size of the recording, or block number identifying
the end of the recording.
The user must specify these parameters before a recording is started. The recording pa-
rameters of all recordings are stored in the recording table, which is located in a system-
reserved partition of the storage device(s).
In order to achieve high speed and deterministic performance, the MDR implements a
recording table instead of a traditional file system. This means that the user has direct
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