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 September 29, 2016 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.Nm 49.Fl C 50.Op Fl v 51.Op Fl f Ar config_file 52.Nm 53.Fl u 54.Op Fl v 55.Ar ccd ... 56.Nm 57.Fl U 58.Op Fl v 59.Op Fl f Ar config_file 60.Nm 61.Fl g 62.Op Fl M Ar core 63.Op Fl N Ar system 64.Op Ar ccd ... 65.Sh DESCRIPTION 66The 67.Nm 68utility is used to dynamically configure and unconfigure concatenated disk 69devices, or ccds. 70For 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. 77This 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. 89If no arguments are specified, every configured ccd is dumped. 90Otherwise, 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. 114The flags may be represented as a decimal number, a hexadecimal number, 115a comma-separated list of strings, or the word 116.Dq none . 117The flags are as follows: 118.Bd -literal -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 was 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 -literal -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/da2s0e /dev/da3s0e 138.Ed 139.Pp 140The component devices need to name partitions of type 141.Li FS_CCD 142(or 143.Dq ccd 144as shown by 145.Xr disklabel 8 ) . 146.Sh RECOVERY 147An error on a ccd disk is usually unrecoverable unless you are using the 148mirroring option. 149But mirroring has its own perils: 150It assumes that both copies of the data at any given sector are the same. 151This holds true 152until a write error occurs or until you replace either side of the mirror. 153This is a poor-man's mirroring implementation. 154It works well enough that if 155you begin to get disk errors you should be able to backup the ccd disk, 156replace the broken hardware, and then regenerate the ccd disk. 157If you need more than this you should look into external hardware RAID 158SCSI boxes, RAID controllers such as the 159.Xr dpt 4 160controller, or software RAID systems such as 161.Xr vinum 8 . 162.Sh FILES 163.Bl -tag -width /etc/ccd.conf -compact 164.It Pa /etc/ccd.conf 165default ccd configuration file 166.El 167.Sh EXAMPLES 168A number of 169.Nm 170examples are shown below. 171The arguments passed to 172.Nm 173are exactly the same as you might place in the 174.Pa /etc/ccd.conf 175configuration file. 176The first example creates a 4-disk stripe out of four SCSI disk partitions. 177The stripe uses a 64 sector interleave. 178The second example is an example of a complex stripe/mirror combination. 179It reads as a two disk stripe of 180.Pa da2s0e 181and 182.Pa da3s0e 183which is mirrored to a two disk stripe of 184.Pa da4s0e 185and 186.Pa da5s0e . 187The last example is a simple mirror. 188.Pa /dev/da2s0e 189is mirrored with 190.Pa /dev/da4s0e 191and assigned to 192.Pa ccd0 . 193.Bd -literal -offset indent 194# ccdconfig ccd0 64 none /dev/da2s0e /dev/da3s0e /dev/da4s0e \e 195 /dev/da5s0e 196# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2s0e /dev/da3s0e \e 197 /dev/da4s0e /dev/da5s0e 198# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2s0e /dev/da4s0e 199.Ed 200.Pp 201When you create a new ccd disk you generally want to label it, using 202.Xr disklabel 8 203or 204.Xr disklabel64 8 , 205before doing anything else. 206Once you create the initial label you can edit it, adding additional partitions. 207The label itself takes up the first 16 sectors of the ccd disk. 208If all you are doing is creating file systems with 209.Xr newfs 8 , 210you do not have to worry about this as 211.Xr newfs 8 212will skip the label area. 213However, if you intend to 214.Xr dd 1 215to or from a ccd partition it is usually a good idea to construct the 216partition such that it does not overlap the label area. 217For example, if you have A ccd disk with 10000 sectors you might create a 218.Ql d 219partition with offset 16 and size 9984. 220.Bd -literal -offset indent 221# disklabel -r -w ccd0s0 auto 222# disklabel -e ccd0s0 223.Ed 224.Pp 225The disklabeling of a ccd disk is usually a one-time affair. 226If you reboot the machine and reconfigure the ccd disk, the disklabel you 227had created before will still be there and not require reinitialization. 228Beware that changing any ccd parameters: interleave, flags, or the 229device list making up the ccd disk, will usually destroy any prior 230data on that ccd disk. 231If this occurs it is usually a good idea to 232reinitialize the label before [re]constructing your ccd disk. 233.Sh SEE ALSO 234.Xr dd 1 , 235.Xr ccd 4 , 236.Xr dpt 4 , 237.Xr disklabel 8 , 238.Xr disklabel64 8 , 239.Xr rc 8 , 240.Xr vinum 8 241.Sh HISTORY 242The 243.Nm 244utility first appeared in 245.Nx 1.1 . 246