.\"	$OpenBSD: twe.4,v 1.17 2003/06/06 10:29:41 jmc Exp $
.\"
.\" Copyright (c) 2000,2001 Michael Shalayeff.  All rights reserved.
.\" Public Domain.
.\"
.Dd September 15, 2000
.Dt TWE 4
.Os
.Sh NAME
.Nm twe
.Nd 3ware Escalade RAID driver
.Sh SYNOPSIS
.Cd "twe* at pci? dev ? function ?"
.Cd "scsibus* at twe?"
.Sh DESCRIPTION
The
.Nm
driver provides support for Escalade family of RAID controllers,
including the
.Tn 3W-5x00 and
.Tn 3W-6x00
models.
.Pp
These controllers support RAID 0, RAID 1, RAID 10 and JBOD
configurations.
All the RAID set volume management is done via the card BIOS.
.Pp
Even though the card uses IDE drives, this driver makes drives
and/or RAID sets appear as
.Xr sd 4 .
.Sh SEE ALSO
.Xr intro 4 ,
.Xr pci 4 ,
.Xr scsi 4 ,
.Xr sd 4
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 2.8 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Michael Shalayeff Aq mickey@openbsd.org ,
inspired by the
.Fx
driver by
.An Mike Smith Aq msmith@freebsd.org .
.Sh BUGS
The card's BIOS seems to conflict with some other disk controllers
which have their own BIOS, if such devices are configured earlier
than this one.
To avoid this situation, place
.Nm
cards in the lowest numbered slot before other SCSI or RAID disk controllers.
.Pp
The current 3ware firmware is known to fail if a redundant configuration
is selected (RAID1 or RAID10) and the array is heavily used
(e.g. installation) before the controller has finished initializing the array.
In this case, create the array, boot the installation media and
leave the array idle until all controller activity has ceased.
.Pp
None of the volumes management or monitoring functions, provided by the
card's firmware, is supported due to the fact that information
on these functions is not public.
.Pp
Only 3W-5400 was tested, but others should work.