diff options
| -rw-r--r-- | examples/guestfs-faq.pod | 19 | ||||
| -rw-r--r-- | sparsify/virt-sparsify.pod | 13 |
2 files changed, 32 insertions, 0 deletions
diff --git a/examples/guestfs-faq.pod b/examples/guestfs-faq.pod index 7ca534ab..28257437 100644 --- a/examples/guestfs-faq.pod +++ b/examples/guestfs-faq.pod @@ -405,6 +405,25 @@ C<$TMPDIR/.guestfs-E<lt>UIDE<gt>> is used instead. It is safe to delete this directory when you are not using libguestfs. +=head2 virt-sparsify seems to make the image grow to the +full size of the virtual disk + +If the input to L<virt-sparsify(1)> is raw, then the output will be +raw sparse. Make sure you are measuring the output with a tool which +understands sparseness such as C<du-sh>. It can make a huge difference: + + $ ls -lh test1.img + -rw-rw-r--. 1 rjones rjones 100M Aug 8 08:08 test1.img + $ du -sh test1.img + 3.6M test1.img + +(Compare the apparent size B<100M> vs the actual size B<3.6M>) + +If all this confuses you, use a non-sparse output by specifying the +I<--convert> option, eg: + + virt-sparsify --convert qcow2 disk.raw disk.qcow2 + =head1 USING LIBGUESTFS IN YOUR OWN PROGRAMS =head2 The API has hundreds of methods, where do I start? diff --git a/sparsify/virt-sparsify.pod b/sparsify/virt-sparsify.pod index 14f7eecb..b716350b 100644 --- a/sparsify/virt-sparsify.pod +++ b/sparsify/virt-sparsify.pod @@ -25,6 +25,19 @@ Virt-sparsify can operate on any disk image, not just ones from virtual machines. If a virtual machine has more than one attached disk, you must sparsify each one separately. +=head2 IMPORTANT NOTE ABOUT SPARSE OUTPUT IMAGES + +If the input is raw, then the default output is raw sparse. B<You +must check the output size using a tool that understands sparseness> +such as C<du -sh>. It can make a huge difference: + + $ ls -lh test1.img + -rw-rw-r--. 1 rjones rjones 100M Aug 8 08:08 test1.img + $ du -sh test1.img + 3.6M test1.img + +(Compare the apparent size B<100M> vs the actual size B<3.6M>) + =head2 IMPORTANT LIMITATIONS =over 4 |