1.\" $NetBSD: ccdconfig.8,v 1.1.2.1 1995/11/11 02:43:33 thorpej Exp $ 2.\" 3.\" Copyright (c) 1995 Jason R. Thorpe. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgment: 16.\" This product includes software developed for the NetBSD Project 17.\" by Jason R. Thorpe. 18.\" 4. The name of the author may not be used to endorse or promote products 19.\" derived from this software without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" $FreeBSD: src/sbin/ccdconfig/ccdconfig.8,v 1.9.2.10 2003/01/26 03:38:39 keramida Exp $ 34.\" $DragonFly: src/sbin/ccdconfig/ccdconfig.8,v 1.2 2003/06/17 04:27:32 dillon Exp $ 35.\" 36.Dd July 17, 1995 37.Dt CCDCONFIG 8 38.Os 39.Sh NAME 40.Nm ccdconfig 41.Nd configuration utility for the concatenated disk driver 42.Sh SYNOPSIS 43.Nm 44.Op Fl cv 45.Ar ccd 46.Ar ileave 47.Op Ar flags 48.Ar dev 49.Op Ar 50.Nm 51.Fl C 52.Op Fl v 53.Op Fl f Ar config_file 54.Nm 55.Fl u 56.Op Fl v 57.Ar ccd 58.Op Ar 59.Nm 60.Fl U 61.Op Fl v 62.Op Fl f Ar config_file 63.Nm 64.Fl g 65.Op Fl M Ar core 66.Op Fl N Ar system 67.Op Ar ccd Op Ar ... 68.Sh DESCRIPTION 69The 70.Nm 71utility is used to dynamically configure and unconfigure concatenated disk 72devices, or ccds. For more information about the ccd, see 73.Xr ccd 4 . 74.Pp 75The options are as follows: 76.Bl -tag -width indent 77.It Fl c 78Configure a ccd. This is the default behavior of 79.Nm . 80.It Fl C 81Configure all ccd devices listed in the ccd configuration file. 82.It Fl f Ar config_file 83When configuring or unconfiguring all devices, read the file 84.Pa config_file 85instead of the default 86.Pa /etc/ccd.conf . 87.It Fl g 88Dump the current ccd configuration in a format suitable for use as the 89ccd configuration file. If no arguments are specified, every configured 90ccd is dumped. Otherwise, the configuration of each listed ccd is dumped. 91.It Fl M Ar core 92Extract values associated with the name list from 93.Pa core 94instead of the default 95.Pa /dev/mem . 96.It Fl N Ar system 97Use 98.Ar system 99as the kernel instead of the running kernel (as determined from 100.Xr getbootfile 3 ) . 101.It Fl u 102Unconfigure a ccd. 103.It Fl U 104Unconfigure all ccd devices listed the ccd configuration file. 105.It Fl v 106Cause 107.Nm 108to be verbose. 109.El 110.Pp 111A ccd is described on the command line and in the ccd configuration 112file by the name of the ccd, the interleave factor, the ccd configuration 113flags, and a list of one or more devices. The flags may be represented 114as a decimal number, a hexadecimal number, a comma-separated list 115of strings, or the word 116.Dq none . 117The flags are as follows: 118.Bd -unfilled -offset indent 119CCDF_SWAP 0x01 Interleave should be dmmax 120CCDF_UNIFORM 0x02 Use uniform interleave 121CCDF_MIRROR 0x04 Support mirroring 122CCDF_PARITY 0x08 Support parity (not implemented yet) 123.Ed 124.Pp 125The format in the 126configuration file appears exactly as if it were entered on the command line. 127Note that on the command line and in the configuration file, the 128.Pa flags 129argument is optional. 130.Bd -unfilled -offset indent 131# 132# /etc/ccd.conf 133# Configuration file for concatenated disk devices 134# 135.Pp 136# ccd ileave flags component devices 137ccd0 16 none /dev/da2e /dev/da3e 138.Ed 139.Pp 140The component devices need to name partitions of type 141.Li FS_BSDFFS 142(or 143.Dq 4.2BSD 144as shown by 145.Xr disklabel 8 ) . 146.Sh EXAMPLES 147A number of 148.Nm 149examples are shown below. The arguments passed 150to 151.Nm 152are exactly the same as you might place in the 153.Pa /etc/ccd.conf 154configuration file. The first example creates a 4-disk stripe out of 155four scsi disk partitions. The stripe uses a 64 sector interleave. 156The second example is an example of a complex stripe/mirror combination. 157It reads as a two disk stripe of da2e and da3e which is mirrored 158to a two disk stripe of da4e and da5e. The last example is a simple 159mirror. /dev/da2e is mirrored with /dev/da4e and assigned to ccd0. 160.Pp 161.Bd -unfilled -offset 162# ccdconfig ccd0 64 none /dev/da2e /dev/da3e /dev/da4e /dev/da5e 163# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da3e /dev/da4e /dev/da5e 164# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da4e 165.Ed 166.Pp 167When you create a new ccd disk you generally want to 168.Xr disklabel 8 169it before doing anything else. Once you create the initial label you can 170edit it, adding additional partitions. The label itself takes up the first 17116 sectors of the ccd disk. If all you are doing is creating file systems 172with newfs, you do not have to worry about this as newfs will skip the 173label area. However, if you intend to 174.Xr dd 1 175to or from a ccd partition it is usually a good idea to construct the 176partition such that it does not overlap the label area. For example, if 177you have A ccd disk with 10000 sectors you might create a 'd' partition 178with offset 16 and size 9984. 179.Pp 180.Bd -unfilled -offset 181# disklabel -r -w ccd0c auto 182# disklabel -e ccd0c 183.Ed 184.Pp 185The disklabeling of a ccd disk is usually a one-time affair. Unlike other 186devices, ccd currently requires that you specify partition 'c' when 187running disklabel. If you reboot the machine and reconfigure the ccd disk, 188the disklabel you 189had created before will still be there and not require reinitialization. 190Beware that changing any ccd parameters: interleave, flags, or the 191device list making up the ccd disk, will usually destroy any prior 192data on that ccd disk. If this occurs it is usually a good idea to 193reinitialize the label before [re]constructing your ccd disk. 194.Sh RECOVERY 195An error on a ccd disk is usually unrecoverable unless you are using the 196mirroring option. But mirroring has its own perils: It assumes that 197both copies of the data at any given sector are the same. This holds true 198until a write error occurs or until you replace either side of the mirror. 199This is a poor-man's mirroring implementation. It works well enough that if 200you begin to get disk errors you should be able to backup the ccd disk, 201replace the broken hardware, and then regenerate the ccd disk. If you need 202more than this you should look into external hardware RAID SCSI boxes, 203RAID controllers such as the 204.Xr dpt 4 205controller, or software RAID systems such as 206.Xr vinum 8 . 207.Sh FILES 208.Bl -tag -width /etc/ccd.conf -compact 209.It Pa /etc/ccd.conf 210default ccd configuration file 211.El 212.Sh SEE ALSO 213.Xr dd 1 , 214.Xr ccd 4 , 215.Xr dpt 4 , 216.Xr disklabel 8 , 217.Xr rc 8 , 218.Xr vinum 8 219.Sh HISTORY 220The 221.Nm 222utility first appeared in 223.Nx 1.0a . 224