UnixWare 7 continues to support the adapters certified with
UnixWare Release 2.1.
Compatible Hardware Web Page
(or the static version on your product CD-ROM)
for a list of host bus adapters certified with UnixWare Release 2.1.
In addition, new or updated HBA drivers are
supplied for Adaptec, Compaq, Data General (CLARiiON), DPT, Mylex,
Qlogic, SymbiosLogic, and others.
Disk stamping in SDI
The SDI subsystem (previously known as PDI) has been
enhanced to support printable disk stamps.
The purpose of disk stamping is to provide a system-wide unique identifier
on each disk medium and to provide access to these identifiers (stamps) outside
of the SDI subsystem. Disk stamps are stored on disk media in the
Physical Disk Information (PDINFO) structures in active UNIX
The sd01 and sdi target drivers and the
commands are enhanced to support the disk stamping feature.
In a multipath I/O environment, there are multiple paths
to any single disk. The name for the disk is determined by the first
path discovered to the disk. Ghost names are provided in UnixWare to avoid
the naming conflicts encountered when controllers fail in this environment.
With this feature, the operating system continues to use the original
device name even when a device is no longer accessible
(or has a different first path).
The system administrator also has the option to run
all references to the ghost names to be the real names.
In SCO UnixWare 1 and 2, when you move a disk from one controller to another, the disk
obtains a new address. A new device node is created for this disk, and
the old device node is removed.
In UnixWare, once a disk is moved from one controller
it occupies two addresses (a mapping between old address and new address).
You cannot add a disk at the old address until you remove the mapping.
is provided in UnixWare 7 to clear the mapping.
Tape data compression characteristics control
The st01 tape target driver is enhanced to support two new ioctls,
namely T_GETCOMP and T_SETCOMP. This allows
system administrators and backup software to control
data compression and decompression hardware features supported by various
SCSI tape drives. Refer to the
manual page for details.
SDI layered storage driver architecture
The SDI subsystem has been extended to provide support for layered
storage device drivers. It is no longer necessary for such drivers to
manipulate private kernel interfaces such as the device switch in order
to intercept I/O requests. SDI now provides a set
of concise, versioned interfaces to support such drivers.
Multi-Path MPIO support in SDI
The first consumer of the newly extended SDI interfaces is
a driver called MPIO. This driver provides support for multiple,
redundant paths to any disk storage device. MPIO will round-robin
I/O requests on each available active I/O path to
a disk, providing maximum disk loading while reducing traffic on
individual SCSI buses. In the case of path failure,
MPIO will automatically re-route I/O
requests to a working path. MPIO also supports storage devices
that support multiple, redundant I/O interfaces and the
switching between those interfaces in the case of a path failure.
SCO OpenServer compatibility
A new command
translates the SCO OpenServer disk layout into the UnixWare layout.
After executing this command the disk is no longer treated as
an SCO OpenServer disk, but instead as a fully supported UnixWare disk.
SCO OpenServer disks can also be read and written without conversion
as long as compatible filesystem formats are used, for example,
the SCO OpenServer s51k format. However, UnixWare SDI administrative
commands such as
will not work on unconverted disks.
In SCO UnixWare 1 and 2 the device addressing model supports 32 devices with
32 Logical Units per device. In UnixWare these
addresses when used by SDI target drivers are replaced
by a simple unsigned integer
(providing 2^32 unique addresses for controllers, buses, logical units
target). They can be translated by SDI into whatever address
is appropriate for the given HBA.