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.\" 35.Dd July 17, 1995 36.Dt CCDCONFIG 8 37.Os 38.Sh NAME 39.Nm ccdconfig 40.Nd configuration utility for the concatenated disk driver 41.Sh SYNOPSIS 42.Nm 43.Op Fl cv 44.Ar ccd 45.Ar ileave 46.Op Ar flags 47.Ar dev 48.Op Ar 49.Nm 50.Fl C 51.Op Fl v 52.Op Fl f Ar config_file 53.Nm 54.Fl u 55.Op Fl v 56.Ar ccd 57.Op Ar 58.Nm 59.Fl U 60.Op Fl v 61.Op Fl f Ar config_file 62.Nm 63.Fl g 64.Op Fl M Ar core 65.Op Fl N Ar system 66.Op Ar ccd Op Ar ... 67.Sh DESCRIPTION 68The 69.Nm 70utility is used to dynamically configure and unconfigure concatenated disk 71devices, or ccds. For more information about the ccd, see 72.Xr ccd 4 . 73.Pp 74The options are as follows: 75.Bl -tag -width indent 76.It Fl c 77Configure a ccd. This is the default behavior of 78.Nm . 79.It Fl C 80Configure all ccd devices listed in the ccd configuration file. 81.It Fl f Ar config_file 82When configuring or unconfiguring all devices, read the file 83.Pa config_file 84instead of the default 85.Pa /etc/ccd.conf . 86.It Fl g 87Dump the current ccd configuration in a format suitable for use as the 88ccd configuration file. If no arguments are specified, every configured 89ccd is dumped. Otherwise, the configuration of each listed ccd is dumped. 90.It Fl M Ar core 91Extract values associated with the name list from 92.Pa core 93instead of the default 94.Pa /dev/mem . 95.It Fl N Ar system 96Use 97.Ar system 98as the kernel instead of the running kernel (as determined from 99.Xr getbootfile 3 ) . 100.It Fl u 101Unconfigure a ccd. 102.It Fl U 103Unconfigure all ccd devices listed the ccd configuration file. 104.It Fl v 105Cause 106.Nm 107to be verbose. 108.El 109.Pp 110A ccd is described on the command line and in the ccd configuration 111file by the name of the ccd, the interleave factor, the ccd configuration 112flags, and a list of one or more devices. The flags may be represented 113as a decimal number, a hexadecimal number, a comma-separated list 114of strings, or the word 115.Dq none . 116The flags are as follows: 117.Bd -unfilled -offset indent 118CCDF_SWAP 0x01 Interleave should be dmmax 119CCDF_UNIFORM 0x02 Use uniform interleave 120CCDF_MIRROR 0x04 Support mirroring 121CCDF_PARITY 0x08 Support parity (not implemented yet) 122.Ed 123.Pp 124The format in the 125configuration file appears exactly as if it were entered on the command line. 126Note that on the command line and in the configuration file, the 127.Pa flags 128argument is optional. 129.Bd -unfilled -offset indent 130# 131# /etc/ccd.conf 132# Configuration file for concatenated disk devices 133# 134.Pp 135# ccd ileave flags component devices 136ccd0 16 none /dev/da2e /dev/da3e 137.Ed 138.Pp 139The component devices need to name partitions of type 140.Li FS_BSDFFS 141(or 142.Dq 4.2BSD 143as shown by 144.Xr disklabel 8 ) . 145.Sh EXAMPLES 146A number of 147.Nm 148examples are shown below. The arguments passed 149to 150.Nm 151are exactly the same as you might place in the 152.Pa /etc/ccd.conf 153configuration file. The first example creates a 4-disk stripe out of 154four scsi disk partitions. The stripe uses a 64 sector interleave. 155The second example is an example of a complex stripe/mirror combination. 156It reads as a two disk stripe of da2e and da3e which is mirrored 157to a two disk stripe of da4e and da5e. The last example is a simple 158mirror. /dev/da2e is mirrored with /dev/da4e and assigned to ccd0. 159.Pp 160.Bd -unfilled -offset 161# ccdconfig ccd0 64 none /dev/da2e /dev/da3e /dev/da4e /dev/da5e 162# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da3e /dev/da4e /dev/da5e 163# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da4e 164.Ed 165.Pp 166When you create a new ccd disk you generally want to 167.Xr disklabel 8 168it before doing anything else. Once you create the initial label you can 169edit it, adding additional partitions. The label itself takes up the first 17016 sectors of the ccd disk. If all you are doing is creating file systems 171with newfs, you do not have to worry about this as newfs will skip the 172label area. However, if you intend to 173.Xr dd 1 174to or from a ccd partition it is usually a good idea to construct the 175partition such that it does not overlap the label area. For example, if 176you have A ccd disk with 10000 sectors you might create a 'd' partition 177with offset 16 and size 9984. 178.Pp 179.Bd -unfilled -offset 180# disklabel -r -w ccd0c auto 181# disklabel -e ccd0c 182.Ed 183.Pp 184The disklabeling of a ccd disk is usually a one-time affair. Unlike other 185devices, ccd currently requires that you specify partition 'c' when 186running disklabel. If you reboot the machine and reconfigure the ccd disk, 187the disklabel you 188had created before will still be there and not require reinitialization. 189Beware that changing any ccd parameters: interleave, flags, or the 190device list making up the ccd disk, will usually destroy any prior 191data on that ccd disk. If this occurs it is usually a good idea to 192reinitialize the label before [re]constructing your ccd disk. 193.Sh RECOVERY 194An error on a ccd disk is usually unrecoverable unless you are using the 195mirroring option. But mirroring has its own perils: It assumes that 196both copies of the data at any given sector are the same. This holds true 197until a write error occurs or until you replace either side of the mirror. 198This is a poor-man's mirroring implementation. It works well enough that if 199you begin to get disk errors you should be able to backup the ccd disk, 200replace the broken hardware, and then regenerate the ccd disk. If you need 201more than this you should look into external hardware RAID SCSI boxes, 202RAID controllers such as the 203.Xr dpt 4 204controller, or software RAID systems such as 205.Xr vinum 8 . 206.Sh FILES 207.Bl -tag -width /etc/ccd.conf -compact 208.It Pa /etc/ccd.conf 209default ccd configuration file 210.El 211.Sh SEE ALSO 212.Xr dd 1 , 213.Xr ccd 4 , 214.Xr dpt 4 , 215.Xr disklabel 8 , 216.Xr rc 8 , 217.Xr vinum 8 218.Sh HISTORY 219The 220.Nm 221utility first appeared in 222.Nx 1.0a . 223