.TH VGCHANGE 8 "LVM TOOLS" "Sistina Software UK" \" -*- nroff -*-
.SH NAME
vgchange \- change attributes of a volume group
.SH SYNOPSIS
.B vgchange
.RB [ \-\-addtag
.IR Tag ]
.RB [ \-\-alloc
.IR AllocationPolicy ]
.RB [ \-A | \-\-autobackup " {" y | n }]
.RB [ \-a | \-\-available " [e|l] {" y | n }]
.RB [ \-d | \-\-debug]
.RB [ \-\-deltag
.IR Tag ]
.RB [ \-h | \-\-help]
.RB [ \-\-ignorelockingfailure]
.RB [ \-l | \-\-logicalvolume
.IR MaxLogicalVolumes ]
.RB [ \-P | \-\-partial]
.RB [ \-s | \-\-physicalextentsize
.IR PhysicalExtentSize [ \fBkKmMgGtT\fR ]]
.RB [ -t | \-\-test]
.RB [ \-v | \-\-verbose]
.RB [ \-\-version ]
.RB [ \-x | \-\-resizeable " {" y | n }]
.RI [ VolumeGroupName ...]
.SH DESCRIPTION
.B vgchange
allows you to change the attributes of one or more volume groups.
Its main purpose is to activate and deactivate
.IR VolumeGroupName ,
or all volume groups if none is specified.  Only active volume groups
are subject to changes and allow access to their logical volumes.
[Not yet implemented: During volume group activation, if
.B vgchange
recognizes snapshot logical volumes which were dropped because they ran
out of space, it displays a message informing the administrator that such
snapshots should be removed (see
.BR lvremove (8)).
]
.SH OPTIONS
See \fBlvm\fP for common options.
.TP
.BR \-A ", " \-\-autobackup { y | n }
Controls automatic backup of metadata after the change.  See
.B vgcfgbackup (8).
Default is yes.
.TP
.BR \-a ", " \-\-available [e|l] { y | n }
Controls the availability of the logical volumes in the volume 
group for input/output.
In other words, makes the logical volumes known/unknown to the kernel.
.IP
If clustered locking is enabled, add 'e' to activate/deactivate
exclusively on one node or 'l' to activate/deactivate only
on the local node.  
Logical volumes with single-host snapshots are always activated
exclusively because they can only be used on one node at once.
.TP
.BR \-l ", " \-\-logicalvolume " " \fIMaxLogicalVolumes\fR
Changes the maximum logical volume number of an existing inactive
volume group.
.TP
.BR \-s ", " \-\-physicalextentsize " " \fIPhysicalExtentSize\fR[\fBkKmMgGtT\fR]
Changes the physical extent size on physical volumes of this volume group.
A size suffix (k for kilobytes up to t for terabytes) is optional, megabytes
is the default if no suffix is present.
The default is 4 MB and it must be at least 1 KB and a power of 2.
 
Before increasing the physical extent size, you might need to use lvresize,
pvresize and/or pvmove so that everything fits.  For example, every
contiguous range of extents used in a logical volume must start and 
end on an extent boundary.
 
If the volume group metadata uses lvm1 format, extents can vary in size from
8KB to 16GB and there is a limit of 65534 extents in each logical volume.  The
default of 4 MB leads to a maximum logical volume size of around 256GB.
 
If the volume group metadata uses lvm2 format those restrictions do not apply,
but having a large number of extents will slow down the tools but have no
impact on I/O performance to the logical volume.  The smallest PE is 1KB.
 
The 2.4 kernel has a limitation of 2TB per block device.
.TP
.BR \-x ", " \-\-resizeable { y | n }
Enables or disables the extension/reduction of this volume group
with/by physical volumes.
.SH EXAMPLES
To activate all known volume groups in the system:
.nf

\	vgchange -a y

.fi
To change the maximum number of logical volumes of inactive volume group
.B vg00
to 128.
.nf

\	vgchange -l 128 /dev/vg00

.fi
.SH SEE ALSO
.BR lvchange (8),
.BR lvm (8),
.BR vgcreate (8)