[src/trunk]: src/share/man/man4 Briefly describe how to enable a number of th...

[oster <oster%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6409a4dad835
branches:  trunk
changeset: 545640:6409a4dad835
user:      oster <oster%NetBSD.org@localhost>
date:      Sat Apr 12 21:20:04 2003 +0000

description:
Briefly describe how to enable a number of the optional RAID types.

Remove wording which suggests that SCSI IDs need to be hard-coded --
this hasn't been a requirement since auto-configure.

diffstat:

 share/man/man4/raid.4 |  101 ++++++++++++++++++++++++++-----------------------
 1 files changed, 54 insertions(+), 47 deletions(-)

diffs (136 lines):

diff -r 628bc737eb45 -r 6409a4dad835 share/man/man4/raid.4
--- a/share/man/man4/raid.4     Sat Apr 12 16:39:19 2003 +0000
+++ b/share/man/man4/raid.4     Sat Apr 12 21:20:04 2003 +0000
@@ -1,4 +1,4 @@
-.\"     $NetBSD: raid.4,v 1.23 2003/04/09 17:41:28 jmmv Exp $
+.\"     $NetBSD: raid.4,v 1.24 2003/04/12 21:20:04 oster Exp $
 .\"
 .\" Copyright (c) 1998 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -103,12 +103,9 @@
 distributed across all the components.
 .El
 .Pp
-There are a wide variety of other RAID levels supported by RAIDframe,
-including Even-Odd parity, RAID level 5 with rotated sparing, Chained
-declustering,  and Interleaved declustering.  The reader is referred
-to the RAIDframe documentation mentioned in the
-.Sx HISTORY
-section for more detail on these various RAID configurations.
+There are a wide variety of other RAID levels supported by RAIDframe.
+The configuration file options to enable them are briefly outlined
+at the end of this section.
 .Pp
 Depending on the parity level configured, the device driver can
 support the failure of component drives.  The number of failures
@@ -155,6 +152,11 @@
 root file system.  See
 .Xr raidctl 8
 for more information on auto-configuration of RAID sets.
+Note that with auto-configuration of RAID sets, it is no longer
+necessary to hard-code SCSI IDs of drives.
+The auto-configuration code will
+correctly configure a device even after any number of the components
+have had their device IDs changed or device names changed.
 .Pp
 The driver supports
 .Sq hot spares ,
@@ -204,46 +206,6 @@
 device can be constructed out of a number of RAID 5 devices (which, in turn,
 may be constructed out of the physical disks, or of other RAID devices).
 .Pp
-It is important that drives be hard-coded at their respective
-addresses (i.e. not left free-floating, where a drive with SCSI ID of
-4 can end up as
-.Pa /dev/sd0c )
-for well-behaved functioning of the RAID device.  This is true for all
-types of drives, including IDE, HP-IB, etc.  For normal SCSI drives, for
-example, the following can be used to fix the device addresses:
-.Bd -unfilled -offset indent
-sd0     at scsibus0 target 0 lun ?      # SCSI disk drives
-sd1     at scsibus0 target 1 lun ?      # SCSI disk drives
-sd2     at scsibus0 target 2 lun ?      # SCSI disk drives
-sd3     at scsibus0 target 3 lun ?      # SCSI disk drives
-sd4     at scsibus0 target 4 lun ?      # SCSI disk drives
-sd5     at scsibus0 target 5 lun ?      # SCSI disk drives
-sd6     at scsibus0 target 6 lun ?      # SCSI disk drives
-.Ed
-.Pp
-See
-.Xr sd 4
-for more information.  The rationale for fixing the device addresses
-is as follows: Consider a system with three SCSI drives at SCSI ID's
-4, 5, and 6, and which map to components
-.Pa /dev/sd0e ,
-.Pa /dev/sd1e ,
-and
-.Pa /dev/sd2e
-of a RAID 5 set.  If the drive with SCSI ID 5 fails, and the
-system reboots, the old
-.Pa /dev/sd2e
-will show up as
-.Pa /dev/sd1e .
-The RAID driver is able to detect that component positions have changed, and
-will not allow normal configuration.  If the device addresses are hard
-coded, however, the RAID driver would detect that the middle component
-is unavailable, and bring the RAID 5 set up in degraded mode.  Note
-that the auto-detection and auto-configuration code does not care
-about where the components live.  The auto-configuration code will
-correctly configure a device even after any number of the components
-have been re-arranged.
-.Pp
 The first step to using the
 .Nm
 driver is to ensure that it is suitably configured in the kernel.  This is
@@ -291,6 +253,51 @@
 .Pp
 These assertions are disabled by default in order to improve
 performance.
+.Pp
+There are a number of less commonly used RAID levels supported by
+RAIDframe.  
+These additional RAID types should be considered experimental, and
+may not be ready for production use.
+The various types and the options to enable them are shown here:
+.Pp 
+For Even-Odd parity:
+.Bd -unfilled -offset indent
+options RF_INCLUDE_EVENODD=1
+.Ed
+.Pp
+For RAID level 5 with rotated sparing:
+.Bd -unfilled -offset indent
+options RF_INCLUDE_RAID5_RS=1
+.Ed
+.Pp
+For Parity Logging (highly experimental):
+.Bd -unfilled -offset indent
+options RF_INCLUDE_PARITYLOGGING=1
+.Ed
+.Pp
+For Chain Declustering:
+.Bd -unfilled -offset indent
+options RF_INCLUDE_CHAINDECLUSTER=1
+.Ed
+.Pp
+For Interleaved Declustering:
+.Bd -unfilled -offset indent
+options RF_INCLUDE_INTERDECLUSTER=1
+.Ed
+.Pp
+For Parity Declustering:
+.Bd -unfilled -offset indent
+options RF_INCLUDE_PARITY_DECLUSTERING=1
+.Ed
+.Pp
+For Parity Declustering with Distributed Spares:
+.Bd -unfilled -offset indent
+options RF_INCLUDE_PARITY_DECLUSTERING_DS=1
+.Ed
+.Pp
+The reader is referred to the RAIDframe documentation mentioned in the
+.Sx HISTORY
+section for more detail on these various RAID configurations.
 .Sh WARNINGS
 Certain RAID levels (1, 4, 5, 6, and others) can protect against some
 data loss due to component failure.  However the loss of two