X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=resize%2Fvirt-resize.pod;h=4ce3a4eabdc7ad58133a77303d628b624f120719;hb=47412f137f2b09dbc2b44b78ba84c0b348e3f402;hp=69c93e38419e7adeebc5c220081c1b80bb86fe42;hpb=d31de200b82ef66d7e87b32dd5345c053997cc35;p=libguestfs.git diff --git a/resize/virt-resize.pod b/resize/virt-resize.pod index 69c93e3..4ce3a4e 100644 --- a/resize/virt-resize.pod +++ b/resize/virt-resize.pod @@ -26,24 +26,48 @@ those manual pages first. =head1 EXAMPLES +=over 4 + +=item 1. + Copy C to C, extending one of the guest's partitions to fill the extra 5GB of space. - truncate -r olddisk newdisk; truncate -s +5G newdisk virt-filesystems --long -h --all -a olddisk + + truncate -r olddisk newdisk + truncate -s +5G newdisk + # Note "/dev/sda2" is a partition inside the "olddisk" file. virt-resize --expand /dev/sda2 olddisk newdisk +=item 2. + As above, but make the /boot partition 200MB bigger, while giving the remaining space to /dev/sda2: - virt-resize --resize /dev/sda1=+200M --expand /dev/sda2 olddisk newdisk + virt-resize --resize /dev/sda1=+200M --expand /dev/sda2 \ + olddisk newdisk + +=item 3. + +As in the first example, but expand a logical volume as the final +step. This is what you would typically use for Linux guests that use +LVM: + + virt-resize --expand /dev/sda2 --LV-expand /dev/vg_guest/lv_root \ + olddisk newdisk + +=item 4. -As above, but the output format will be uncompressed qcow2: +As in the first example, but the output format will be qcow2 instead +of a raw disk: qemu-img create -f qcow2 newdisk.qcow2 15G virt-resize --expand /dev/sda2 olddisk newdisk.qcow2 +=back + =head1 DETAILED USAGE =head2 EXPANDING A VIRTUAL MACHINE DISK @@ -133,9 +157,9 @@ to fill the rest of the available space: If the expanded partition in the image contains a filesystem or LVM PV, then if virt-resize knows how, it will resize the contents, the equivalent of calling a command such as L, -L or L. However virt-resize does not -know how to resize some filesystems, so you would have to online -resize them after booting the guest. +L, L or L. However virt-resize +does not know how to resize some filesystems, so you would have to +online resize them after booting the guest. Other options are covered below. @@ -222,57 +246,80 @@ C
) Display help. -=item B<-V> +=item B<--align-first auto> -=item B<--version> +=item B<--align-first never> -Display version number and exit. +=item B<--align-first always> -=item B<--resize part=size> +Align the first partition for improved performance (see also the +I<--alignment> option). -Resize the named partition (expanding or shrinking it) so that it has -the given size. +The default is I<--align-first auto> which only aligns the first +partition if it is safe to do so. That is, only when we know how to +fix the bootloader automatically, and at the moment that can only be +done for Windows guests. -C can be expressed as an absolute number followed by -b/K/M/G to mean bytes, Kilobytes, Megabytes, or Gigabytes; -or as a percentage of the current size; -or as a relative number or percentage. -For example: +I<--align-first never> means we never move the first partition. +This is the safest option. Try this if the guest does not boot +after resizing. - --resize /dev/sda2=10G +I<--align-first always> means we always align the first partition (if +it needs to be aligned). For some guests this will break the +bootloader, making the guest unbootable. - --resize /dev/sda4=90% +=item B<--alignment N> - --resize /dev/sda2=+1G +Set the alignment of partitions to C sectors. The default in +virt-resize E 1.13.19 was 64 sectors, and after that is 128 +sectors. - --resize /dev/sda2=-200M +Assuming 512 byte sector size inside the guest, here are some +suitable values for this: - --resize /dev/sda1=+128K +=over 4 - --resize /dev/sda1=+10% +=item I<--alignment 1> (512 bytes) - --resize /dev/sda1=-10% +The partitions would be packed together as closely as possible, but +would be completely unaligned. In some cases this can cause very poor +performance. See L for further details. -You can increase the size of any partition. Virt-resize will expand -the direct content of the partition if it knows how (see I<--expand> -below). +=item I<--alignment 8> (4K) -You can only I the size of partitions that contain -filesystems or PVs which have already been shrunk. Virt-resize will -check this has been done before proceeding, or else will print an -error (see also I<--resize-force>). +This would be the minimum acceptable alignment for reasonable +performance on modern hosts. -You can give this option multiple times. +=item I<--alignment 128> (64K) -=item B<--resize-force part=size> +This alignment provides good performance when the host is using high +end network storage. -This is the same as I<--resize> except that it will let you decrease -the size of any partition. Generally this means you will lose any -data which was at the end of the partition 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). +=item I<--alignment 2048> (1M) -See also the I<--ignore> option. +This is the standard alignment used by all newly installed guests +since around 2008. + +=back + +=item B<-d> + +=item B<--debug> + +Enable debugging messages. + +=item B<--delete part> + +Delete the named partition. 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 when you delete a partition, then anything contained in the +partition is also deleted. Furthermore, this causes any partitions +that come after to be I, which can easily make your guest +unbootable. + +You can give this option multiple times. =item B<--expand part> @@ -290,13 +337,11 @@ Currently virt-resize can resize: =item * -ext2, ext3 and ext4 filesystems when they are contained -directly inside a partition. +ext2, ext3 and ext4 filesystems. =item * -NTFS filesystems contained directly in a partition, if libguestfs was -compiled with support for NTFS. +NTFS filesystems, if libguestfs was compiled with support for NTFS. The filesystem must have been shut down consistently last time it was used. Additionally, L marks the resized filesystem as @@ -309,27 +354,24 @@ LVM PVs (physical volumes). virt-resize does not usually resize anything inside the PV, but see the I<--LV-expand> option. The user could also resize LVs as desired after boot. +=item * + +Btrfs filesystems, if libguestfs was compiled with support for btrfs. + =back Note that you cannot use I<--expand> and I<--shrink> together. -=item B<--shrink part> +=item B<--format> raw -Shrink the named partition until the overall disk image fits in the -destination. The named partition B contain a filesystem or PV -which has already been shrunk using another tool (eg. L -or other online tools). Virt-resize will check this and give an error -if it has not been done. +Specify the format of the input disk image. If this flag is not +given then it is auto-detected from the image itself. -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 a partition to shrink and that partition had more than a -gigabyte of free space. +If working with untrusted raw-format guest disk images, you should +ensure the format is always specified. -Note that you cannot use I<--expand> and I<--shrink> together. +Note that this option I affect the output format. +See L. =item B<--ignore part> @@ -340,19 +382,6 @@ blank (all zero bytes). You can give this option multiple times. -=item B<--delete part> - -Delete the named partition. 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 when you delete a partition, then anything contained in the -partition is also deleted. Furthermore, this causes any partitions -that come after to be I, which can easily make your guest -unbootable. - -You can give this option multiple times. - =item B<--LV-expand logvol> This takes the logical volume and, as a final step, expands it to fill @@ -376,6 +405,18 @@ You can give this option multiple times, I it doesn't make sense to do this unless the logical volumes you specify are all in different volume groups. +=item B<--machine-readable> + +This option is used to make the output more machine friendly +when being parsed by other programs. See +L below. + +=item B<-n> + +=item B<--dryrun> + +Print a summary of what would be done, but don't do anything. + =item B<--no-copy-boot-loader> By default, virt-resize copies over some sectors at the start of the @@ -413,17 +454,18 @@ You have to use this option if you want to resize a Windows guest multiple times without booting into Windows between each resize. -=item B<-d> - -=item B<--debug> - -Enable debugging messages. +=item B<--output-format> raw -=item B<-n> +Specify the format of the output disk image. If this flag is not +given then it is auto-detected from the image itself. -=item B<--dryrun> +If working with untrusted raw-format guest disk images, you should +ensure the format is always specified. -Print a summary of what would be done, but don't do anything. +Note that this option I the output format. This +option just tells libguestfs what it is so it doesn't try to guess it. +You still need to create the output disk with the right format. See +L. =item B<-q> @@ -431,51 +473,149 @@ Print a summary of what would be done, but don't do anything. Don't print the summary. -=item B<--format> raw +=item B<--resize part=size> -Specify the format of the input disk image. If this flag is not -given then it is auto-detected from the image itself. +Resize the named partition (expanding or shrinking it) so that it has +the given size. -If working with untrusted raw-format guest disk images, you should -ensure the format is always specified. +C can be expressed as an absolute number followed by +b/K/M/G to mean bytes, Kilobytes, Megabytes, or Gigabytes; +or as a percentage of the current size; +or as a relative number or percentage. +For example: -Note that this option I affect the output format. -See L. + --resize /dev/sda2=10G -=item B<--output-format> raw + --resize /dev/sda4=90% -Specify the format of the output disk image. If this flag is not -given then it is auto-detected from the image itself. + --resize /dev/sda2=+1G -If working with untrusted raw-format guest disk images, you should -ensure the format is always specified. + --resize /dev/sda2=-200M -Note that this option I the output format. This -option just tells libguestfs what it is so it doesn't try to guess it. -You still need to create the output disk with the right format. See -L. + --resize /dev/sda1=+128K + + --resize /dev/sda1=+10% + + --resize /dev/sda1=-10% + +You can increase the size of any partition. Virt-resize will expand +the direct content of the partition if it knows how (see I<--expand> +below). + +You can only I the size of partitions that contain +filesystems or PVs which have already been shrunk. Virt-resize will +check this has been done before proceeding, or else will print an +error (see also I<--resize-force>). + +You can give this option multiple times. + +=item B<--resize-force part=size> + +This is the same as I<--resize> except that it will let you decrease +the size of any partition. Generally this means you will lose any +data which was at the end of the partition 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). + +See also the I<--ignore> option. + +=item B<--shrink part> + +Shrink the named partition until the overall disk image fits in the +destination. The named partition B contain a filesystem or PV +which has already been shrunk using another tool (eg. L +or other online tools). Virt-resize will check this and give an error +if it has not been done. + +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 a partition to shrink and that partition had more than a +gigabyte of free space. + +Note that you cannot use I<--expand> and I<--shrink> together. + +=item B<-V> + +=item B<--version> + +Display version number and exit. + +=back + +=head1 MACHINE READABLE OUTPUT + +The I<--machine-readable> option can be used to make the output more +machine friendly, which is useful when calling virt-resize from other +programs, GUIs etc. + +There are two ways to use this option. + +Firstly use the option on its own to query the capabilities of the +virt-resize binary. Typical output looks like this: + + $ virt-resize --machine-readable + virt-resize + ntfsresize-force + 32bitok + ntfs + btrfs + +A list of features is printed, one per line, and the program exits +with status 0. + +Secondly use the option in conjunction with other options to make the +regular program output more machine friendly. + +At the moment this means: + +=over 4 + +=item 1. + +Progress bar messages can be parsed from stdout by looking for this +regular expression: + + ^[0-9]+/[0-9]+$ + +=item 2. + +The calling program should treat messages sent to stdout (except for +progress bar messages) as status messages. They can be logged and/or +displayed to the user. + +=item 3. + +The calling program should treat messages sent to stderr as error +messages. In addition, virt-resize exits with a non-zero status code +if there was a fatal error. =back +Versions of the program prior to 1.13.9 did not support the +I<--machine-readable> option and will return an error. + =head1 NOTES =head2 "Partition 1 does not end on cylinder boundary." -Virt-resize aligns partitions to multiples of 64 sectors. Usually -this means the partitions will not be aligned to the ancient CHS -geometry. However CHS geometry is meaningless for disks manufactured -since the early 1990s, and doubly so for virtual hard drives. -Alignment of partitions to cylinders is not required by any modern -operating system. +Virt-resize aligns partitions to multiples of 128 sectors (see the +I<--alignment> parameter). Usually this means the partitions will not +be aligned to the ancient CHS geometry. However CHS geometry is +meaningless for disks manufactured since the early 1990s, and doubly +so for virtual hard drives. Alignment of partitions to cylinders is +not required by any modern operating system. =head2 RESIZING WINDOWS VIRTUAL MACHINES In Windows Vista and later versions, Microsoft switched to using a separate boot partition. In these VMs, typically C is the -boot partition and C is the main (C:) drive. We have not -had any luck resizing the boot partition. Doing so seems to break the -guest completely. However expanding the second partition (ie. C: -drive) should work. +boot partition and C is the main (C:) drive. Resizing the +first (boot) partition causes the bootloader to fail with +C<0xC0000225> error. Resizing the second partition (ie. C: drive) +should work. Windows may initiate a lengthy "chkdsk" on first boot after a resize, if NTFS partitions have been expanded. This is just a safety check @@ -484,9 +624,7 @@ and (unless it find errors) is nothing to worry about. =head2 GUEST BOOT STUCK AT "GRUB" If a Linux guest does not boot after resizing, and the boot is stuck -after printing C on the console, try reinstalling grub. This -sometimes happens on older (RHEL 5-era) guests, for reasons we don't -fully understand, although we think is to do with partition alignment. +after printing C on the console, try reinstalling grub. guestfish -i -a newdisk > cat /boot/grub/device.map @@ -521,6 +659,11 @@ have meaning to the shell such as C<#> and space. You may need to quote or escape these characters on the command line. See the shell manual page L for details. +=head1 EXIT STATUS + +This program returns 0 if successful, or non-zero if there was an +error. + =head1 SEE ALSO L, @@ -532,6 +675,7 @@ L, L, L, L, +L, L, L, L, @@ -539,6 +683,8 @@ L, L, L, L, +L, +L, L. =head1 AUTHOR