freebsd/sbin/gvinum/gvinum.8

.\"  Copyright (c) 2005 Chris Jones
.\"  All rights reserved.
.\"
.\" This software was developed for the FreeBSD Project by Chris Jones
.\" thanks to the support of Google's Summer of Code program and
.\" mentoring by Lukas Ertl.
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.Dd March 23, 2006
.Dt GVINUM 8
.Os
.Sh NAME
.Nm gvinum
.Nd Logical Volume Manager control program
.Sh SYNOPSIS
.Nm
.Op Ar command
.Op Fl options
.Sh COMMANDS
.Bl -tag -width indent
.It Ic attach Ar plex volume Op Cm rename
.It Ic attach Ar subdisk plex Oo Ar offset Oc Op Cm rename
Attach a plex to a volume, or a subdisk to a plex. 
If offset is specified, the subdisk will be attached to the given offset within
the plex.
If rename is specified, the subdisk or plex will change name according to the
object it attaches to.
.It Ic checkparity Oo Fl f Oc Ar plex
Check the parity blocks of a RAID-5 plex.
The parity check will start at the
beginning of the plex if the
.Fl f
flag is specified, or otherwise at the location of the parity check pointer,
the first location at which plex's parity is incorrect.
All subdisks in the
plex must be up for a parity check.
.It Ic concat Oo Fl fv Oc Oo Fl n Ar name Oc Ar drives
Create a concatenated volume from the specified drives.
If no name is specified, a unique name will be set by gvinum.
.It Ic create Oo Fl f Oc Op Ar description-file
Create a volume as described in
.Ar description-file .
If no
.Ar description-file
provided, opens an editor and provides the current
.Nm
configuration for editing.
The
.Fl f
flag will make gvinum ignore any errors regarding creating objects that already
exists.
However, in contrast to vinum, objects that are not properly named in the
.Ar description-file
will not be created when the
.Fl f
flag is given.
.It Ic detach Oo Fl f Oc Op Ar plex | subdisk
Detach a plex or subdisk from the volume or plex to which it is
attached.
.It Ic help
Provides a synopsis of
.Nm
commands and arguments.
.It Ic l | list Oo Fl rvV Oc Op Ar volume | plex | subdisk
.It Ic ld Oo Fl rvV Oc Op Ar drive ...
.It Ic ls Oo Fl rvV Oc Op Ar subdisk ...
.It Ic lp Oo Fl rvV Oc Op Ar plex ...
.It Ic lv Oo Fl rvV Oc Op Ar volume ...
List information about the relevant object(s).
The
.Fl r
flag provides recursive display, showing each object's subordinate objects in
proper relation.
The
.Fl v
and
.Fl V
flags provide progressively more detailed output.
.It Ic mirror Oo Fl fsv Oc Oo Fl n Ar name Oc Ar drives
Create a mirrored volume from the specified drives. 
It requires at least a multiple of 2 drives.
If no name is specified, a unique name will be set by gvinum.
If the 
.Fl s
flag is specified, a striped mirror will be created, and thus requires a
multiple of 4 drives.
.It Ic move | mv Fl f Ar drive subdisk Op Ar ...
Move the subdisk(s) to the specified drive.
The
.Fl f
flag is required, as all data on the indicated subdisk(s) will be destroyed as
part of the move.
This can currently only be done when the subdisk is
not being accessed.
.Pp
If a single subdisk is moved, and it forms a part of a RAID-5 plex, the moved
subdisks will need to be set to the
.Dq stale
state, and the plex will require a
.Ic start
command.
If multiple subdisk(s) is moved, and form part of a RAID-5 plex, the
moved disk(s) will need to be set to the
.Dq up
state and the plex will require a
.Ic rebuildparity
command.
If the subdisk(s) form part of a plex that is mirrored with other
plexes, the plex will require restarting and will sync once restarted.
Moving
more than one subdisk in a RAID-5 plex or subdisks from both sides of a
mirrored plex volume will destroy data.
Note that parity rebuilds and syncing
must be started manually after a move.
.It Ic printconfig
Write a copy of the current configuration to standard output.
.It Ic quit
Exit
.Nm
when running in interactive mode.
Normally this would be done by entering the
EOF character.
.It Ic raid5 Oo Fl fv Oc Oo Fl s Ar stripesize Oc Oo Fl n Ar name Oc Ar drives
Create a RAID-5 volume from the specified drives.
If no name is specified,a unique name will be set by
.Ic gvinum. 
This organization requires at least three drives.
.It Ic rename Oo Fl r Oc Ar drive | subdisk | plex | volume newname
Change the name of the specified object.
The
.Fl r
flag will recursively rename subordinate objects.
.Pp
Note that device nodes will not be renamed until
.Nm
is restarted.
.It Ic rebuildparity Oo Fl f Oc Ar plex
Rebuild the parity blocks of a RAID-5 plex.
The parity rebuild will start at
the beginning of the plex if the
.Fl f
flag is specified, or otherwise at the location of the parity check pointer.
All subdisks in the plex must be up for a parity check.
.It Ic resetconfig
Reset the complete
.Nm
configuration.
.It Ic rm Oo Fl r Oc Ar volume | plex | subdisk
Remove an object and, if
.Fl r
is specified, its subordinate objects.
.It Ic saveconfig
Save
.Nm
configuration to disk after configuration failures.
.It Ic setstate Oo Fl f Oc Ar state volume | plex | subdisk | drive
Set state without influencing other objects, for diagnostic purposes
only.
The
.Fl f
flag forces state changes regardless of whether they are legal.
.It Ic start
Read configuration from all vinum drives.
.It Ic start Oo Fl S Ar size Oc Ar volume | plex | subdisk
Allow the system to access the objects.
If necessary, plexes will be synced and rebuilt.
If a subdisk was added to a running RAID-5 or striped plex, gvinum will
expand into this subdisk and grow the whole RAID-5 array.
This can be done without unmounting your filesystem.
The
.Fl S
flag is currently ignored.
.It Ic stop Oo Fl f Oc Op Ar volume | plex | subdisk
Terminate access to the objects, or stop
.Nm
if no parameters are specified.
.It Ic stripe Oo Fl fv Oc Oo Fl n Ar name Oc Ar drives
Create a striped volume from the specified drives. If no name is specified,
a unique name will be set by Ic gvinum. This organization requires at least two
drives.
.El
.Sh DESCRIPTION
The
.Nm
utility communicates with the kernel component of the GVinum logical volume
manager.
It is designed either for interactive use, when started without
command line arguments, or to execute a single command if the command is
supplied on the command line.
In interactive mode,
.Nm
maintains a command line history.
.Sh OPTIONS
The
.Nm
commands may be followed by an option.
.Bl -tag -width indent
.It Fl f
The
.Fl f
.Pq Dq force
option overrides safety checks.
It should be used with extreme caution.
This
option is required in order to use the
.Ic move
command.
.It Fl r
The
.Fl r
.Pq Dq recursive
option applies the command recursively to subordinate objects.
For example, in
conjunction with the
.Ic lv
command, the
.Fl r
option will also show information about the plexes and subdisks belonging to
the volume.
It is also used by the
.Ic rename
command to indicate that subordinate objects such as subdisks should be renamed
to match the object(s) specified and by the
.Ic rm
command to delete plexes belonging to a volume and so on.
.It Fl v
The
.Fl v
.Pq Dq verbose
option provides more detailed output.
.It Fl V
The
.Fl V
.Pq Dq "very verbose"
option provides even more detailed output than
.Fl v .
.El
.Sh ENVIRONMENT
.Bl -tag -width ".Ev EDITOR"
.It Ev EDITOR
The name of the editor to use for editing configuration files, by
default
.Xr vi 1
is invoked.
.El
.Sh FILES
.Bl -tag -width ".Pa /dev/gvinum/plex"
.It Pa /dev/gvinum
directory with device nodes for
.Nm
objects
.El
.Sh EXAMPLES
To create a mirror on disks /dev/ad1 and /dev/ad2, create a filesystem, mount,
unmount and then stop Ic gvinum:
.Pp
.Dl "gvinum mirror /dev/ad1 /dev/ad2"
.Dl "newfs /dev/gvinum/gvinumvolume0"
.Dl "mount /dev/gvinum/gvinumvolume0 /mnt" 
.Dl "..."
.Dl "unmount /mnt"
.Dl "gvinum stop"
.Pp
To create a striped mirror on disks /dev/ad1 /dev/ad2 /dev/ad3 and /dev/ad4
named "data" and create a filesystem:
.Pp
.Dl "gvinum mirror -s -n data /dev/ad1 /dev/ad2 /dev/ad3 /dev/ad4"
.Dl "newfs /dev/gvinum/data"
.Pp
To create a raid5 array on disks /dev/ad1 /dev/ad2 and /dev/ad3, with stripesize
493k you can use the raid5 command:
.Pp
.Dl "gvinum raid5 -s 493k /dev/ad1 /dev/ad2 /dev/ad3"
.Pp
Then the volume will be created automatically.
Afterwards, you have to initialize the volume:
.Pp
.Dl "gvinum start myraid5vol"
.Pp
The initialization will start, and the states will be updated when it's
finished.
The list command will give you information about its progress.
.Pp
Imagine that one of the drives fails, and the output of 'printconfig' looks
something like this:
.Pp
.Dl "drive gvinumdrive1 device /dev/ad2"
.Dl "drive gvinumdrive2 device /dev/???"
.Dl "drive gvinumdrive0 device /dev/ad1"
.Dl "volume myraid5vol"
.Dl "plex name myraid5vol.p0 org raid5 986s vol myraid5vol"
.Dl "sd name myraid5vol.p0.s2 drive gvinumdrive2 len 32538s driveoffset 265s"
.Dl "plex myraid5vol.p0 plexoffset 1972s"
.Dl "sd name myraid5vol.p0.s1 drive gvinumdrive1 len 32538s driveoffset 265s"
.Dl "plex myraid5vol.p0 plexoffset 986s"
.Dl "sd name myraid5vol.p0.s0 drive gvinumdrive0 len 32538s driveoffset 265s"
.Dl "plex myraid5vol.p0 plexoffset 0s"
.Pp
Create a new drive with this configuration:
.Pp
.Dl "drive gdrive4 device /dev/ad4"
.Pp
Then move the stale subdisk to the new drive:
.Pp
.Dl "gvinum move gdrive4 myraid5vol.p0.s2"
.Pp
Then, initiate the rebuild:
.Pp
.Dl "gvinum start myraid5vol.p0"
.Pp
The plex will go up form degraded mode after the rebuild is finished.
The plex can still be used while the rebuild is in progress, although requests
might be delayed.
For a more advanced usage and detailed explanation of gvinum, the
handbook is recommended.
.Pp
Given the configuration as in the previous example, growing a RAID-5 or STRIPED
array is accomplished by adding a new subdisk to the plex with a
.Ar description-file
similar to this:
.Pp
.Dl "drive newdrive device /dev/ad4"
.Dl "sd drive newdrive plex myraid5vol.p0"
.Pp
If everything went ok, the plex state should now be set to growable.
You can then start the growing with the
.Ic start
command:
.Pp
.Dl "gvinum start myraid5vol.p0"
.Pp
As with rebuilding, you can watch the progress using the
.Ic list
command.
.Pp
.Sh SEE ALSO
.Xr geom 4 ,
.Xr geom 8
.Sh HISTORY
The
.Nm
utility first appeared in
.Fx 5.3 .
The
.Nm vinum
utility, on which
.Nm
is based, was written by
.An "Greg Lehey" .
.Pp
The
.Nm
utility
was written by
.An "Lukas Ertl" .
The
.Ic move
and
.Ic rename
commands and
documentation were added by
.An "Chris Jones"
through the 2005 Google Summer
of Code program.
.Ic a partial rewrite of gvinum was done by "Lukas Ertl" and "Ulf Lilleengen"
through the 2007 Google Summer of Code program.
The documentation have been updated to reflect the new functionality.
.Sh AUTHORS
.An Lukas Ertl Aq le@FreeBSD.org
.An Chris Jones Aq soc-cjones@FreeBSD.org
.An Ulf Lilleengen Aq lulf@FreeBSD.org
.Sh BUGS
Currently,
.Nm
does not rename devices in
.Pa /dev/gvinum
until reloaded.
.Pp
The
.Fl S
initsize flag to
.Ic start
is ignored.
.Pp
Moving subdisks that are not part of a mirrored or RAID-5 volume will
destroy data.
It is perhaps a bug to permit this.
.Pp
Plexes in which subdisks have been moved do not automatically sync or
rebuild parity.
This may leave data unprotected and is perhaps unwise.
.Pp
Currently,
.Nm
does not yet fully implement all of the functions found in
.Xr vinum 4 .
Specifically, the following commands from
.Xr vinum 4
are not supported:
.Bl -tag -width indent
.It Ic debug
Cause the volume manager to enter the kernel debugger.
.It Ic debug Ar flags
Set debugging flags.
.It Ic dumpconfig Op Ar drive ...
List the configuration information stored on the specified drives, or all
drives in the system if no drive names are specified.
.It Ic info Op Fl vV
List information about volume manager state.
.It Ic label Ar volume
Create a volume label.
.It Ic resetstats Oo Fl r Oc Op Ar volume | plex | subdisk
Reset statistics counters for the specified objects, or for all objects if none
are specified.
.It Ic setdaemon Op Ar value
Set daemon configuration.
.El