freebsd-dev/sbin/geom/class/raid3/graid3.8

.\" Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org>
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.\" $FreeBSD$
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.Dd Aug 20, 2004
.Dt GRAID3 8
.Os
.Sh NAME
.Nm graid3
.Nd "control utility for RAID3 devices"
.Sh SYNOPSIS
.Nm
.Cm label
.Op Fl hnrv
.Ar name
.Ar prov
.Ar prov
.Ar prov
.Op Ar prov Op Ar ...
.Nm
.Cm clear
.Op Fl v
.Ar prov
.Op Ar prov Op Ar ...
.Nm
.Cm configure
.Op Fl adhnrRv
.Ar name
.Nm
.Cm rebuild
.Op Fl v
.Ar name
.Ar prov
.Nm
.Cm insert
.Op Fl hv
.Fl n Ar number
.Ar name
.Ar prov
.Nm
.Cm remove
.Op Fl v
.Fl n Ar number
.Ar name
.Nm
.Cm stop
.Op Fl fv
.Ar name
.Op Ar name Op Ar ...
.Nm
.Cm list
.Op Ar name Op Ar ...
.Nm
.Cm load
.Op Fl v
.Nm
.Cm unload
.Op Fl v
.Sh DESCRIPTION
The
.Nm
utility is used for RAID3 arrays configuration.
After a device creation, all components are detected and configured
automatically.
All operations like failure detection, stale components detection, rebuild
of stale components etc.\& are done automatically as well.
The
.Nm
utility uses on-disk metadata (the last provider's sector) to store all needed
information.
.Pp
The first argument to
.Nm
indicates an action to be performed:
.Bl -tag -width ".Cm configure"
.It Cm label
Create a RAID3 device.
The last given component will contain parity data, all the rest - regular data.
Number of components has to be equal to 3, 5, 9, 17, etc\&. (2^n + 1).
.Pp
Additional options include:
.Bl -tag -width ".Fl h"
.It Fl h
Hardcode providers' names in metadata.
.It Fl n
Turn off autosynchronization of stale components.
.It Fl r
Use parity component for reading in round-robin fashion.
Without this option parity component is not used at all for reading operations
when device is in complete state.
With this option specified random I/O read operations are even 40% faster,
but sequential reads are slower.
.El
.It Cm clear
Clear metadata on the given providers.
.It Cm configure
Configure the given device.
.Pp
Additional options include:
.Bl -tag -width ".Fl a"
.It Fl a
Turn on autosynchronization of stale components.
.It Fl d
Do not hardcode providers' names in metadata.
.It Fl h
Hardcode providers' names in metadata.
.It Fl n
Turn off autosynchronization of stale components.
.It Fl r
Turn on round-robin reading.
.It Fl R
Turn off round-robin reading.
.El
.It Cm rebuild
Rebuild the given component forcibly.
If autosynchronization wasn't turn off for the given device, this command
hopefully will not be used.
.It Cm insert
Add the given component to the existing array, if one of the component was
removed previously with the
.Cm remove
command or one component is missing and will not be connected again.
.Pp
Additional options include:
.Bl -tag -width ".Fl h"
.It Fl h
Hardcode providers' names in metadata.
.El
.It Cm remove
Remove the given component from the given array and clear metadata on it.
.It Cm stop
Stop the given arrays.
.Pp
Additional options include:
.Bl -tag -width ".Fl f"
.It Fl f
Stop the given array even if it is opened.
.El
.It Cm list
List every currently configured devices, if a list of devices is passed as a
parameter then only those devices will be shown.
.It Cm load
Load
.Pa geom_raid3.ko
kernel module.
.It Cm unload
Unload
.Pa geom_raid3.ko
kernel module.
.El
.Pp
Additional options include:
.Bl -tag -width ".Fl v"
.It Fl v
Be more verbose.
.El
.Sh EXAMPLES
Use 3 disks to setup a RAID3 array (use round-robin reading feature).
Create a file system, mount it, then unmount it and stop device:
.Bd -literal -offset indent
graid3 label -v -r data da0 da1 da2
newfs /dev/raid3/data
mount /dev/raid3/data /mnt
[...]
umount /mnt
graid3 stop data
graid3 unload
.Ed
.Pp
.Pp
Create a RAID3 array, but do not use automatic sunchronization feature.
Rebuild parity component:
.Bd -literal -offset indent
graid3 label -n data da0 da1 da2
graid3 rebuild data da2
.Ed
.Pp
Replace one data disk with a brand new one:
.Bd -literal -offset indent
graid3 remove -n 0 data
graid3 insert -n 0 data da5
.Ed
.Sh DIAGNOSTICS
Exit status is 0 on success, and 1 if the command fails.
.Sh SEE ALSO
.Xr geom 4 ,
.Xr geom 8 ,
.Xr mount 8 ,
.Xr newfs 8 ,
.Xr umount 8 ,
.Xr vinum 8
.Sh HISTORY
The
.Nm
utility appeared in
.Fx 5.3 .
.Sh AUTHORS
.An Pawel Jakub Dawidek Aq pjd@FreeBSD.org
.Sh BUGS
There should be a section with implementation description.