Make CCD be able to read and write Linux software raids.

Supported for raid-0 with <n> disks, raid-1 with 2 disks.

Manpages have examples, warnings etc.

Test scripts on
http://www.cons.org/cracauer/ccdconfig-linux/
Reviewed by:	alfred

1 files changed, 16 insertions, 0 deletions

diff --git a/sbin/ccdconfig/ccdconfig.8 b/sbin/ccdconfig/ccdconfig.8
index 4ba08be..bbd7428 100644
--- a/sbin/ccdconfig/ccdconfig.8
+++ b/sbin/ccdconfig/ccdconfig.8
@@ -104,6 +104,8 @@ The flags are as follows:
 .Bd -literal -offset indent
 CCDF_UNIFORM	0x02		Use uniform interleave
 CCDF_MIRROR	0x04		Support mirroring
+CCDF_NO_OFFSET	0x08		Do not use an offset
+CCDF_LINUX	0x0A		Linux md(4) compatibility
 .Ed
 .Pp
 The format in the
@@ -127,6 +129,10 @@ The component devices need to name partitions of type
 .Dq 4.2BSD
 as shown by
 .Xr disklabel 8 ) .
+.Pp
+If you want to use the Linux md(4) compatibility mode, please be sure
+to read the notes in
+.Xr ccd 4 .
 .Sh FILES
 .Bl -tag -width /etc/ccd.conf -compact
 .It Pa /etc/ccd.conf
@@ -159,6 +165,16 @@ and assigned to ccd0.
 # ccdconfig ccd0 128 CCDF_MIRROR /dev/da8s2 /dev/da9s3
 .Ed
 .Pp
+The following are matching commands in Linux and FreeBSD to create a
+raid-0 in Linux and read it from FreeBSD.
+.Bd -literal
+# Create a raid-0 on Linux:
+mdadm --create --chunk=32 --level=0 --raid-devices=2 /dev/md0 \\
+   /dev/hda1 /dev/hdb1
+# Make the raid-0 just created available on FreeBSD:
+ccdconfig -c /dev/ccd0 32 linux /dev/ad0s1 /dev/ad0s2
+.Ed
+.Pp
 When you create a new ccd disk you generally want to
 .Xr fdisk 8
 and