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.\" 4. The name of the author may not be used to endorse or promote products 15.\" derived from this software without specific prior written permission. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 22.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 24.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 25.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27.\" SUCH DAMAGE. 28.\" 29.\" $FreeBSD$ 30.\" 31.Dd July 17, 1995 32.Dt CCDCONFIG 8 33.Os 34.Sh NAME 35.Nm ccdconfig 36.Nd configuration utility for the concatenated disk driver 37.Sh SYNOPSIS 38.Nm 39.Op Fl cv 40.Ar ccd 41.Ar ileave 42.Op Ar flags 43.Ar dev 44.Op Ar 45.Nm 46.Fl C 47.Op Fl v 48.Op Fl f Ar config_file 49.Nm 50.Fl u 51.Op Fl v 52.Ar ccd 53.Op Ar 54.Nm 55.Fl U 56.Op Fl v 57.Op Fl f Ar config_file 58.Nm 59.Fl g 60.Op Ar ccd Op Ar ... 61.Sh DESCRIPTION 62The 63.Nm 64utility is used to dynamically configure and unconfigure concatenated disk 65devices, or ccds. For more information about the ccd, see 66.Xr ccd 4 . 67.Pp 68The options are as follows: 69.Bl -tag -width indent 70.It Fl c 71Configure a ccd. This is the default behavior of 72.Nm . 73.It Fl C 74Configure all ccd devices listed in the ccd configuration file. 75.It Fl f Ar config_file 76When configuring or unconfiguring all devices, read the file 77.Pa config_file 78instead of the default 79.Pa /etc/ccd.conf . 80.It Fl g 81Dump the current ccd configuration in a format suitable for use as the 82ccd configuration file. If no arguments are specified, every configured 83ccd is dumped. Otherwise, the configuration of each listed ccd is dumped. 84.It Fl u 85Unconfigure a ccd. 86.It Fl U 87Unconfigure all ccd devices listed the ccd configuration file. 88.It Fl v 89Cause 90.Nm 91to be verbose. 92.El 93.Pp 94A ccd is described on the command line and in the ccd configuration 95file by the name of the ccd, the interleave factor, the ccd configuration 96flags, and a list of one or more devices. The flags may be represented 97as a decimal number, a hexadecimal number, a comma-separated list 98of strings, or the word 99.Dq none . 100The flags are as follows: 101.Bd -unfilled -offset indent 102CCDF_UNIFORM 0x02 Use uniform interleave 103CCDF_MIRROR 0x04 Support mirroring 104.Ed 105.Pp 106The format in the 107configuration file appears exactly as if it were entered on the command line. 108Note that on the command line and in the configuration file, the 109.Pa flags 110argument is optional. 111.Bd -unfilled -offset indent 112# 113# /etc/ccd.conf 114# Configuration file for concatenated disk devices 115# 116.Pp 117# ccd ileave flags component devices 118ccd0 16 none /dev/da2s1 /dev/da3s1 119.Ed 120.Pp 121The component devices need to name partitions of type 122.Li FS_BSDFFS 123(or 124.Dq 4.2BSD 125as shown by 126.Xr disklabel 8 ) . 127.Sh EXAMPLES 128A number of 129.Nm 130examples are shown below. The arguments passed 131to 132.Nm 133are exactly the same as you might place in the 134.Pa /etc/ccd.conf 135configuration file. The first example creates a 4-disk stripe out of 136four scsi disk partitions. The stripe uses a 64 sector interleave. 137The second example is an example of a complex stripe/mirror combination. 138It reads as a two disk stripe of da4 and da5 which is mirrored 139to a two disk stripe of da6 and da7. The last example is a simple 140mirror. The 2nd slice of /dev/da8 is mirrored with the 3rd slice of /dev/da9 141and assigned to ccd0. 142.Pp 143.Bd -unfilled -offset 144# ccdconfig ccd0 64 none /dev/da0s1 /dev/da1s1 /dev/da2s1 /dev/da3s1 145# ccdconfig ccd0 128 CCDF_MIRROR /dev/da4 /dev/da5 /dev/da6 /dev/da7 146# ccdconfig ccd0 128 CCDF_MIRROR /dev/da8s2 /dev/da9s3 147.Ed 148.Pp 149When you create a new ccd disk you generally want to 150.Xr fdisk 8 151and 152.Xr disklabel 8 153it before doing anything else. Once you create the initial label you can 154edit it, adding additional partitions. The label itself takes up the first 15516 sectors of the ccd disk. If all you are doing is creating file systems 156with newfs, you do not have to worry about this as newfs will skip the 157label area. However, if you intend to 158.Xr dd 1 159to or from a ccd partition it is usually a good idea to construct the 160partition such that it does not overlap the label area. For example, if 161you have A ccd disk with 10000 sectors you might create a 'd' partition 162with offset 16 and size 9984. 163.Pp 164.Bd -unfilled -offset 165# disklabel ccd0 > /tmp/disklabel.ccd0 166# disklabel -Rr ccd0 /tmp/disklabel.ccd0 167# disklabel -e ccd0 168.Ed 169.Pp 170The disklabeling of a ccd disk is usually a one-time affair. 171If you reboot the machine and reconfigure the ccd disk, 172the disklabel you 173had created before will still be there and not require reinitialization. 174Beware that changing any ccd parameters: interleave, flags, or the 175device list making up the ccd disk, will usually destroy any prior 176data on that ccd disk. If this occurs it is usually a good idea to 177reinitialize the label before [re]constructing your ccd disk. 178.Sh RECOVERY 179An error on a ccd disk is usually unrecoverable unless you are using the 180mirroring option. But mirroring has its own perils: It assumes that 181both copies of the data at any given sector are the same. This holds true 182until a write error occurs or until you replace either side of the mirror. 183This is a poor-man's mirroring implementation. It works well enough that if 184you begin to get disk errors you should be able to backup the ccd disk, 185replace the broken hardware, and then regenerate the ccd disk. If you need 186more than this you should look into external hardware RAID SCSI boxes, 187RAID controllers (see GENERIC), 188or software RAID systems such as 189RAIDframe 190.Xr raid 4 191and 192.Xr vinum 8 . 193.Sh FILES 194.Bl -tag -width /etc/ccd.conf -compact 195.It Pa /etc/ccd.conf 196default ccd configuration file 197.El 198.Sh SEE ALSO 199.Xr dd 1 , 200.Xr ccd 4 , 201.Xr raid 4 , 202.Xr disklabel 8 , 203.Xr fdisk 8 , 204.Xr rc 8 , 205.Xr vinum 8 206.Sh BUGS 207The initial disklabel returned by 208.Xr ccd 4 209specifies only 3 partitions. 210One needs to change the number of paritions to 8 using 211.Dq Nm disklabel Fl e 212to get the usual 213.Bx 214expectations. 215.Sh HISTORY 216The 217.Nm 218utility first appeared in 219.Nx 1.0a . 220