nvrd(7) DG/UX 5.4.2 nvrd(7)
NAME
nvrd - AViiON family non-volatile disk subsystem
DESCRIPTION
The nvrd disk subsystem consists of the set of VME-based non-volatile
RAM boards which supports the following units:
Model # Size
5018VME 2 Mbyte Special Systems ECC non-volatile memory board
The nvrd provides a physical disk interface to the board. A physical
disk unit may be accessed directly via the special file nodes in
/dev/pdsk and /dev/rpdsk. These nodes are named in the form:
/dev/[r]pdsk/nvrd@device-code(cr-addr,mem-addr,size)
where device-code is the hexadecimal device code of the device, cr-
addr is the VME address of the control registers, mem-addr is the VME
address of the memory, and size is the size of the board in
megabytes.
The nvrd subsystem has 8 built-in defaults for the device code,
control register address, memory address, and size. When using the
defaults, the following short form of the nvrd device specification
can be used:
nvrd(number)
where number identifies the following corresponding long form of the
device.
Short Form Device Code/Control/Memory/Size
nvrd(0) 0x80/0xFFFFFF00/0xE5000000/2
nvrd(1) 0x82/0xFFFFFF20/0xE5200000/2
nvrd(2) 0x84/0xFFFFFF40/0xE5400000/2
nvrd(3) 0x86/0xFFFFFF60/0xE5600000/2
nvrd(4) 0x88/0xFFFFFF80/0xE5800000/2
nvrd(5) 0x8A/0xFFFFFFA0/0xE5A00000/2
nvrd(6) 0x8C/0xFFFFFFC0/0xE5C00000/2
nvrd(7) 0x8E/0xFFFFFFE0/0xE5E00000/2
The entries in the above table skip a set of device codes and control
register addresses in the long form of the device. The reason for
this is the support of mirrored boards. Each of the above eight
configurations for the nvrd can run mirrored. This is done by
setting the DIP switches for the device code, control register
address, and memory address to the above settings. This board is
considered the master and is the only board in a mirrored pair that
is configured. The slave board, which is not configured, must have
its DIP switches set to values that correspond to the master board.
The correspondence is the following:
device-code should be set to one greater on the slave board.
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nvrd(7) DG/UX 5.4.2 nvrd(7)
cr-address should be set to 0x10 greater on the slave board.
memory-address should be identical on the slave board.
DIP Switches Master Slave
device code 80 81
cr-address FFFFFF00 FFFFFF10
memory-address E5000000 E5000000
If one of the boards in a mirrored pair fails, a message will be sent
to the system console and logged. Because the boards are mirrored,
no application using the boards will notice the failure. To avoid
the loss of data if a failure of one of the boards occurs, the
following instructions must be applied.
If the board that failed is the slave board, then it can be repaired
or replaced with the same DIP switch settings. If the board that
failed is the master board, then the slave board must have its DIP
switch settings set to the master. The master board must be repaired
or replaced with its DIP switch settings set to the previous slave's
settings.
The nodes in /dev/pdsk provide access as a block special device as
described in dsk(7). The nodes in /dev/rpdsk provide access as a
character special device as described in rdsk(7). When accessing a
disk through a /dev/pdsk or /dev/rpdsk node, the operating system
performs no bad block remapping.
FILES
/dev/pdsk/*
/dev/rpdsk/*
SEE ALSO
dsk(7), rdsk(7).
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