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 ccdconfig 43.Op Fl cv 44.Ar ccd 45.Ar ileave 46.Op Ar flags 47.Ar dev 48.Op Ar 49.Nm ccdconfig 50.Fl C 51.Op Fl v 52.Op Fl f Ar config_file 53.Nm ccdconfig 54.Fl u 55.Op Fl v 56.Ar ccd 57.Op Ar 58.Nm ccdconfig 59.Fl U 60.Op Fl v 61.Op Fl f Ar config_file 62.Nm ccdconfig 63.Fl g 64.Op Fl M Ar core 65.Op Fl N Ar system 66.Oo 67.Ar ccd Oo ... 68.Oc 69.Oc 70.Sh DESCRIPTION 71.Nm Ccdconfig 72is used to dynamically configure and unconfigure concatenated disk 73devices, or ccds. For more information about the ccd, see 74.Xr ccd 4 . 75.Pp 76The options are as follows: 77.Bl -tag -width indent 78.It Fl c 79Configure a ccd. This is the default behavior of 80.Nm Ns . 81.It Fl C 82Configure all ccd devices listed in the ccd configuration file. 83.It Fl f Ar config_file 84When configuring or unconfiguring all devices, read the file 85.Pa config_file 86instead of the default 87.Pa /etc/ccd.conf . 88.It Fl g 89Dump the current ccd configuration in a format suitable for use as the 90ccd configuration file. If no arguments are specified, every configured 91ccd is dumped. Otherwise, the configuration of each listed ccd is dumped. 92.It Fl M Ar core 93Extract values associated with the name list from 94.Pa core 95instead of the default 96.Pa /dev/mem . 97.It Fl N Ar system 98Use 99.Ar system 100as the kernel instead of the running kernel (as determined from 101.Xr getbootfile 3 ). 102.It Fl u 103Unconfigure a ccd. 104.It Fl U 105Unconfigure all ccd devices listed the ccd configuration file. 106.It Fl v 107Cause 108.Nm 109to be verbose. 110.El 111.Pp 112A ccd is described on the command line and in the ccd configuration 113file by the name of the ccd, the interleave factor, the ccd configuration 114flags, and a list of one or more devices. The flags may be represented 115as a decimal number, a hexadecimal number, a comma-separated list 116of strings, or the word 117.Dq none . 118The flags are as follows: 119.Bd -unfilled -offset indent 120CCDF_SWAP 0x01 Interleave should be dmmax 121CCDF_UNIFORM 0x02 Use uniform interleave 122CCDF_MIRROR 0x04 Support mirroring 123CCDF_PARITY 0x08 Support parity (not implemented yet) 124.Ed 125.Pp 126The format in the 127configuration file appears exactly as if it were entered on the command line. 128Note that on the command line and in the configuration file, the 129.Pa flags 130argument is optional. 131.Bd -unfilled -offset indent 132# 133# /etc/ccd.conf 134# Configuration file for concatenated disk devices 135# 136.Pp 137# ccd ileave flags component devices 138ccd0 16 none /dev/da2e /dev/da3e 139.Ed 140.Pp 141The component devices need to name partitions of type 142.Li FS_BSDFFS 143(or 144.Dq 4.2BSD 145as shown by 146.Xr disklabel 8 ). 147.Sh EXAMPLE 148.Pp 149A number of ccdconfig examples are shown below. The arguments passed 150to ccdconfig are exactly the same as you might place in the 151.Pa /etc/ccd.conf 152configuration file. The first example creates a 4-disk stripe out of 153four scsi disk partitions. The stripe uses a 64 sector interleave. 154The second example is an example of a complex stripe/mirror combination. 155It reads as a two disk stripe of da2e and da3e which is mirrored 156to a two disk stripe of da4e and da5e. The last example is a simple 157mirror. /dev/da2e is mirrored with /dev/da4e and assigned to ccd0. 158.Pp 159.Bd -unfilled -offset 160# ccdconfig ccd0 64 none /dev/da2e /dev/da3e /dev/da4e /dev/da5e 161# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da3e /dev/da4e /dev/da5e 162# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da4e 163.Ed 164.Pp 165When you create a new ccd disk you generally want to 166.Nm disklabel 167it before doing anything else. Once you create the initial label you can 168edit it, adding additional partitions. The label itself takes up the first 16916 sectors of the ccd disk. If all you are doing is creating filesystems 170with newfs, you do not have to worry about this as newfs will skip the 171label area. However, if you intend to 172.Nm dd 173to or from a ccd partition it is usually a good idea to construct the 174partition such that it does not overlap the label area. For example, if 175you have A ccd disk with 10000 sectors you might create a 'd' partition 176with offset 16 and size 9984. 177.Pp 178.Bd -unfilled -offset 179# disklabel -r -w ccd0c auto 180# disklabel -e ccd0c 181.Ed 182.Pp 183The disklabeling of a ccd disk is usually a one-time affair. Unlike other 184devices, ccd currently requires that you specify partition 'c' when 185running disklabel. If you reboot the machine and reconfigure the ccd disk, 186the disklabel you 187had created before will still be there and not require reinitialization. 188Beware that changing any ccd parameters: interleave, flags, or the 189device list making up the ccd disk, will usually destroy any prior 190data on that ccd disk. If this occurs it is usually a good idea to 191reinitialize the label before [re]constructing your ccd disk. 192.Pp 193.Sh RECOVERY 194.Pp 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. 199.Nm Ccd 200uses a poor-man's mirroring implementation. It works well enough that if 201you begin to get disk errors you should be able to backup the ccd disk, 202replace the broken hardware, and then regenerate the ccd disk. If you need 203more then this you should look into external hardware RAID SCSI boxes, 204RAID controllers such as the 205.Nm dpt 206controller, or software RAID systems such as 207.Nm vinum . 208.Pp 209.Sh FILES 210.Bl -tag -width /etc/ccd.conf -compact 211.It Pa /etc/ccd.conf 212default ccd configuration file 213.El 214.Sh SEE ALSO 215.Xr ccd 4 , 216.Xr rc 8 217.Xr vinum 8 218.Sh HISTORY 219The 220.Nm 221command first appeared in 222.Nx 1.0a . 223