NAME virt-resize - Resize a virtual machine disk SYNOPSIS virt-resize [--options] indisk outdisk DESCRIPTION Virt-resize is a tool which can resize a virtual machine disk, making it larger or smaller overall, and resizing or deleting any partitions and filesystems contained within. Virt-resize cannot resize disk images in-place. Virt-resize should not be used on live virtual machines - for consistent results, shut the virtual machine down before resizing it. This program is intended to be used in conjunction with virt-list-filesystems(1) and virt-df(1). You should read the manpages for those tools if you are not already familiar with them. BASIC USAGE 1. Locate disk image Locate the disk image that you want to resize. It could be in a local file or device. If the guest is managed by libvirt, you can use "virsh dumpxml" like this to find the disk image name: # virsh dumpxml guestname | xpath /domain/devices/disk/source Found 1 nodes: -- NODE -- 2. Look at current sizing Use virt-list-filesystems(1) and/or virt-df(1) on the disk image to find out what is currently inside the disk image, and how much free space is available. For example: # virt-df -h /dev/vg/lv_guest Filesystem Size Used Available Use% /dev/vg/lv_guest:/dev/sda1 98.7M 35.4M 58.3M 41.0% /dev/vg/lv_guest:/dev/VolGroup00/LogVol00 8.6G 8.0G 0.1G 98.8% In this example the filesystems are called "/dev/sda1" and "/dev/VolGroup00/LogVol00". 3. Create destination disk Virt-resize cannot do in-place disk modifications. You have to have space to store the resized destination disk. To store the resized disk image in a file, create a file of a suitable size: # truncate -s 10G outdisk Use lvcreate(1) to create a logical volume: # lvcreate -L 10G -n lv_name vg_name Or use virsh(1) vol-create-as to create a libvirt storage volume: # virsh pool-list # virsh vol-create-as poolname newvol 10G 4. Resize virt-resize indisk outdisk This command just copies disk image "indisk" to disk image "outdisk" *without* resizing or changing any existing partitions or filesystems. If "outdisk" is larger, then an extra, empty partition is created at the end of the disk covering the extra space. If "outdisk" is smaller, then it will give an error. To resize, you need to pass extra options (for the full list see the "OPTIONS" section below). "--expand" is the most useful option. It expands the named filesystem within the disk to fill any extra space: virt-resize --expand /dev/sda1 indisk outdisk (In this case, an extra partition is *not* created at the end of the disk, because there will be no unused space). If "/dev/sda1" in the image contains a filesystem, then the filesystem is resized (if possible because only some filesystem types support resizing). Other options are covered below. 5. Test Thoroughly test the new disk image *before* discarding the old one. If you are using libvirt, edit the XML to point at the new disk: # virsh edit guestname Change , see Then start up the domain with the new, resized disk: # virsh start guestname and check that it still works. OPTIONS In the options below, "fs" means some filesystem name, eg. "/dev/sda1" or "/dev/VolGroup00/LogVol00". Use virt-list-filesystems(1) and/or virt-df(1) to list the names of filesystems within an image. --help Display brief help. --version Display version number and exit. --resize fs=size Resize the named filesystem (expanding or shrinking it) so that it has the given size. "size" can be expressed as an absolute number followed by s/K/M/G/T/P/E to mean sectors, Kilobytes, Megabytes, Gigabytes, Terabytes, Petabytes or Exabytes; or as a percentage of the current size; or as a relative number or percentage. For example: --resize /dev/sda2=10G --resize /dev/VolGroup00/LogVol00=90% --resize /dev/sda2=+1G --resize /dev/sda2=-200M --resize /dev/sda1=+128s --resize /dev/VolGroup00/LogVol00=+10% --resize /dev/VolGroup00/LogVol00=-10% You can increase the size of anything: filesystems, partitions, PVs or LVs. If you increase the size of a filesystem, then virt-resize will try to resize the filesystem itself to fit the extra space. This is only possible for ext2/3/4, NTFS and LVM PV. You can *only* decrease the size of ext2/3/4 filesystems, NTFS and LVM PVs, and then only if there is free space in the filesystem or PV to shrink it. You can give this option multiple times. --resize-force fs=size This is the same as "--resize" except that it will let you decrease the size of anything. Generally this means you will lose any data which was at the end of the thing you shrink, but you may not care about that (eg. if shrinking an unused partition, or if you can easily recreate it such as a swap partition). --expand fs --expand percent:fs Expand the named filesystem so it uses up all extra space (space left over after any other filesystem changes that you request have been done). You can give this option multiple times: --expand fs1 --expand fs2 which divides the extra space equally between fs1 and fs2. You can also prefix each filesystem with a percentage, thus: --expand 20:fs1 --expand 50:fs2 will give 20% of the extra space to fs1, 50% to fs2, and the remainder (30%) will go into an extra partition. If possible, we resize the filesystem to fit the extra space. This can be done for ext2/3/4 and NTFS filesystems, and LVM PVs. You can also expand partitions and LVM LVs. Note that you cannot use "--expand" and "--shrink" together. --shrink fs --shrink percent:fs Shrink the named filesystem until the overall disk image fits in the destination. The named filesystem must be ext2/3/4, NTFS or an LVM PV, and it must have enough free space to allow it to be shrunk. The amount by which the overall disk must be shrunk (after carrying out all other operations requested by the user) is called the "deficit". For example, a straight copy (assume no other operations) from a 5GB disk image to a 4GB disk image results in a 1GB deficit. In this case, virt-resize would give an error unless the user specified at least one filesystem to shrink and that filesystem had more than a gigabyte of free space. You can give this option multiple times: --shrink fs1 --shrink fs2 which divides the deficit equally between fs1 and fs2. You can also prefix each filesystem with a percentage in order to spread the deficit unequally: --shrink 20:fs1 --shrink 80:fs2 Note that you cannot use "--expand" and "--shrink" together. --zero fs Zero out the named filesystem. Effectively this means the filesystem is created on the destination disk, but the content is not copied across from the source disk. You can zero out partitions, filesystems or any LVM object. This applies recursively, so for example if you zero out an LVM VG, then none of the LVs or filesystems inside that VG are copied over. You can give this option multiple times. --delete fs Delete the named filesystem, partition or LVM object. It would be more accurate to describe this as "don't copy it over", since virt-resize doesn't do in-place changes and the original disk image is left intact. Note that if you delete a partition, then anything contained in the partition is also deleted. Furthermore, this causes any partitions that come after to be *renumbered*. Also if you delete an LVM object, then anything contained in that LVM object is deleted too. So for example, deleting an LVM VG deletes any LVs inside that VG. You can give this option multiple times. --no-copy-boot-loader By default, virt-resize copies over some sectors at the start of the disk (up to the beginning of the first partition). Commonly these sectors contain the Master Boot Record (MBR) and the boot loader, and are required in order for the guest to boot correctly. If you specify this flag, then this initial copy is not done. You may need to reinstall the boot loader in this case. --no-extra-partition By default, virt-resize creates an extra partition if there is any extra, unused space after all resizing has happened. Use this option to prevent the extra partition from being created. If you do this then the extra space will be inaccessible until you run "fdisk" in the guest. --no-resize-fs By default, virt-resize will resize ext2/3/4 and NTFS filesystems, and LVM PVs (not merely the containers they are in). If you use this option, then only the container is resized, not the filesystem. Note that if this option is specified, then virt-resize will refuse to shrink anything unless you use "--resize-force". -d | --debug Enable debugging messages. -n | --dryrun Print a summary of what would be done, but don't do anything. -q | --quiet Don't print the summary. SEE ALSO virt-list-filesystems(1), virt-df(1), guestfs(3), guestfish(1), Sys::Guestfs(3), Sys::Guestfs::Lib(3), . AUTHOR Richard W.M. Jones COPYRIGHT Copyright (C) 2010 Red Hat Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.