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.\" $DragonFly: src/sbin/ccdconfig/ccdconfig.8,v 1.7 2008/05/02 02:05:05 swildner Exp $ 35.\" 36.Dd February 8, 2009 37.Dt CCDCONFIG 8 38.Os 39.Sh NAME 40.Nm ccdconfig 41.Nd configuration utility for the concatenated disk driver 42.Sh SYNOPSIS 43.Nm 44.Op Fl cv 45.Ar ccd 46.Ar ileave 47.Op Ar flags 48.Ar dev ... 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.Nm 58.Fl U 59.Op Fl v 60.Op Fl f Ar config_file 61.Nm 62.Fl g 63.Op Fl M Ar core 64.Op Fl N Ar system 65.Op Ar ccd ... 66.Sh DESCRIPTION 67The 68.Nm 69utility is used to dynamically configure and unconfigure concatenated disk 70devices, or ccds. 71For 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. 78This is the default behavior of 79.Nm . 80.It Fl C 81Configure all ccd devices listed in the ccd configuration file. 82.It Fl f Ar config_file 83When configuring or unconfiguring all devices, read the file 84.Pa config_file 85instead of the default 86.Pa /etc/ccd.conf . 87.It Fl g 88Dump the current ccd configuration in a format suitable for use as the 89ccd configuration file. 90If no arguments are specified, every configured ccd is dumped. 91Otherwise, 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. 115The flags may be represented as a decimal number, a hexadecimal number, 116a comma-separated list of strings, or the word 117.Dq none . 118The flags are as follows: 119.Bd -literal -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 -literal -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/da2s0e /dev/da3s0e 139.Ed 140.Pp 141The component devices need to name partitions of type 142.Li FS_CCD 143(or 144.Dq ccd 145as shown by 146.Xr disklabel 8 ) . 147.Sh RECOVERY 148An error on a ccd disk is usually unrecoverable unless you are using the 149mirroring option. 150But mirroring has its own perils: 151It assumes that both copies of the data at any given sector are the same. 152This holds true 153until a write error occurs or until you replace either side of the mirror. 154This is a poor-man's mirroring implementation. 155It works well enough that if 156you begin to get disk errors you should be able to backup the ccd disk, 157replace the broken hardware, and then regenerate the ccd disk. 158If you need more than this you should look into external hardware RAID 159SCSI boxes, RAID controllers such as the 160.Xr dpt 4 161controller, or software RAID systems such as 162.Xr vinum 8 . 163.Sh FILES 164.Bl -tag -width /etc/ccd.conf -compact 165.It Pa /etc/ccd.conf 166default ccd configuration file 167.El 168.Sh EXAMPLES 169A number of 170.Nm 171examples are shown below. 172The arguments passed to 173.Nm 174are exactly the same as you might place in the 175.Pa /etc/ccd.conf 176configuration file. 177The first example creates a 4-disk stripe out of four SCSI disk partitions. 178The stripe uses a 64 sector interleave. 179The second example is an example of a complex stripe/mirror combination. 180It reads as a two disk stripe of 181.Pa da2s0e 182and 183.Pa da3s0e 184which is mirrored to a two disk stripe of 185.Pa da4s0e 186and 187.Pa da5s0e . 188The last example is a simple mirror. 189.Pa /dev/da2s0e 190is mirrored with 191.Pa /dev/da4s0e 192and assigned to 193.Pa ccd0 . 194.Bd -literal -offset indent 195# ccdconfig ccd0 64 none /dev/da2s0e /dev/da3s0e /dev/da4s0e \e 196 /dev/da5s0e 197# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2s0e /dev/da3s0e \e 198 /dev/da4s0e /dev/da5s0e 199# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2s0e /dev/da4s0e 200.Ed 201.Pp 202When you create a new ccd disk you generally want to label it, using 203.Xr disklabel 8 204or 205.Xr disklabel64 8 , 206before doing anything else. 207Once you create the initial label you can edit it, adding additional partitions. 208The label itself takes up the first 16 sectors of the ccd disk. 209If all you are doing is creating file systems with 210.Xr newfs 8 , 211you do not have to worry about this as 212.Xr newfs 8 213will skip the label area. 214However, if you intend to 215.Xr dd 1 216to or from a ccd partition it is usually a good idea to construct the 217partition such that it does not overlap the label area. 218For example, if you have A ccd disk with 10000 sectors you might create a 219.Ql d 220partition with offset 16 and size 9984. 221.Bd -literal -offset indent 222# disklabel -r -w ccd0s0 auto 223# disklabel -e ccd0s0 224.Ed 225.Pp 226The disklabeling of a ccd disk is usually a one-time affair. 227If you reboot the machine and reconfigure the ccd disk, the disklabel you 228had created before will still be there and not require reinitialization. 229Beware that changing any ccd parameters: interleave, flags, or the 230device list making up the ccd disk, will usually destroy any prior 231data on that ccd disk. 232If this occurs it is usually a good idea to 233reinitialize the label before [re]constructing your ccd disk. 234.Sh SEE ALSO 235.Xr dd 1 , 236.Xr ccd 4 , 237.Xr dpt 4 , 238.Xr disklabel 8 , 239.Xr disklabel64 8 , 240.Xr rc 8 , 241.Xr vinum 8 242.Sh HISTORY 243The 244.Nm 245utility first appeared in 246.Nx 1.0a . 247