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.\" $FreeBSD$ 34.\" 35.Dd July 17, 1995 36.Dt CCDCONFIG 8 37.Os FreeBSD 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 68.Nm Ccdconfig 69is used to dynamically configure and unconfigure concatenated disk 70devices, or ccds. For more information about the ccd, see 71.Xr ccd 4 . 72.Pp 73The options are as follows: 74.Bl -tag -width indent 75.It Fl c 76Configure a ccd. This is the default behavior of 77.Nm . 78.It Fl C 79Configure all ccd devices listed in the ccd configuration file. 80.It Fl f Ar config_file 81When configuring or unconfiguring all devices, read the file 82.Pa config_file 83instead of the default 84.Pa /etc/ccd.conf . 85.It Fl g 86Dump the current ccd configuration in a format suitable for use as the 87ccd configuration file. If no arguments are specified, every configured 88ccd is dumped. Otherwise, the configuration of each listed ccd is dumped. 89.It Fl M Ar core 90Extract values associated with the name list from 91.Pa core 92instead of the default 93.Pa /dev/mem . 94.It Fl N Ar system 95Use 96.Ar system 97as the kernel instead of the running kernel (as determined from 98.Xr getbootfile 3 ) . 99.It Fl u 100Unconfigure a ccd. 101.It Fl U 102Unconfigure all ccd devices listed the ccd configuration file. 103.It Fl v 104Cause 105.Nm 106to be verbose. 107.El 108.Pp 109A ccd is described on the command line and in the ccd configuration 110file by the name of the ccd, the interleave factor, the ccd configuration 111flags, and a list of one or more devices. The flags may be represented 112as a decimal number, a hexadecimal number, a comma-separated list 113of strings, or the word 114.Dq none . 115The flags are as follows: 116.Bd -unfilled -offset indent 117CCDF_SWAP 0x01 Interleave should be dmmax 118CCDF_UNIFORM 0x02 Use uniform interleave 119CCDF_MIRROR 0x04 Support mirroring 120CCDF_PARITY 0x08 Support parity (not implemented yet) 121.Ed 122.Pp 123The format in the 124configuration file appears exactly as if it were entered on the command line. 125Note that on the command line and in the configuration file, the 126.Pa flags 127argument is optional. 128.Bd -unfilled -offset indent 129# 130# /etc/ccd.conf 131# Configuration file for concatenated disk devices 132# 133.Pp 134# ccd ileave flags component devices 135ccd0 16 none /dev/da2e /dev/da3e 136.Ed 137.Pp 138The component devices need to name partitions of type 139.Li FS_BSDFFS 140(or 141.Dq 4.2BSD 142as shown by 143.Xr disklabel 8 ) . 144.Sh EXAMPLES 145.Pp 146A number of ccdconfig examples are shown below. The arguments passed 147to ccdconfig are exactly the same as you might place in the 148.Pa /etc/ccd.conf 149configuration file. The first example creates a 4-disk stripe out of 150four scsi disk partitions. The stripe uses a 64 sector interleave. 151The second example is an example of a complex stripe/mirror combination. 152It reads as a two disk stripe of da2e and da3e which is mirrored 153to a two disk stripe of da4e and da5e. The last example is a simple 154mirror. /dev/da2e is mirrored with /dev/da4e and assigned to ccd0. 155.Pp 156.Bd -unfilled -offset 157# ccdconfig ccd0 64 none /dev/da2e /dev/da3e /dev/da4e /dev/da5e 158# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da3e /dev/da4e /dev/da5e 159# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da4e 160.Ed 161.Pp 162When you create a new ccd disk you generally want to 163.Nm disklabel 164it before doing anything else. Once you create the initial label you can 165edit it, adding additional partitions. The label itself takes up the first 16616 sectors of the ccd disk. If all you are doing is creating filesystems 167with newfs, you do not have to worry about this as newfs will skip the 168label area. However, if you intend to 169.Nm dd 170to or from a ccd partition it is usually a good idea to construct the 171partition such that it does not overlap the label area. For example, if 172you have A ccd disk with 10000 sectors you might create a 'd' partition 173with offset 16 and size 9984. 174.Pp 175.Bd -unfilled -offset 176# disklabel -r -w ccd0c auto 177# disklabel -e ccd0c 178.Ed 179.Pp 180The disklabeling of a ccd disk is usually a one-time affair. Unlike other 181devices, ccd currently requires that you specify partition 'c' when 182running disklabel. If you reboot the machine and reconfigure the ccd disk, 183the disklabel you 184had created before will still be there and not require reinitialization. 185Beware that changing any ccd parameters: interleave, flags, or the 186device list making up the ccd disk, will usually destroy any prior 187data on that ccd disk. If this occurs it is usually a good idea to 188reinitialize the label before [re]constructing your ccd disk. 189.Pp 190.Sh RECOVERY 191.Pp 192An error on a ccd disk is usually unrecoverable unless you are using the 193mirroring option. But mirroring has its own perils: It assumes that 194both copies of the data at any given sector are the same. This holds true 195until a write error occurs or until you replace either side of the mirror. 196.Nm Ccd 197uses a poor-man's mirroring implementation. It works well enough that if 198you begin to get disk errors you should be able to backup the ccd disk, 199replace the broken hardware, and then regenerate the ccd disk. If you need 200more then this you should look into external hardware RAID SCSI boxes, 201RAID controllers such as the 202.Nm dpt 203controller, or software RAID systems such as 204.Nm vinum . 205.Pp 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 ccd 4 , 213.Xr rc 8 , 214.Xr vinum 8 215.Sh HISTORY 216The 217.Nm 218command first appeared in 219.Nx 1.0a . 220