Home / server / Questions / 334586
Accepted
Can Kavaklıoğlu
Asked: 2011-11-25 12:39:19 +0800 CST

Howto resize Xen virtual host disk size on Debian?

  • 772

I am using a loop device disk setup (not lvm) for Xen Debian (squeeze) guest systems on my Debian (squeeze) host system.

I searched for a way of extending guest system disk size. I came accross simple dd commands and nasty mkfs commands.

I wonder if there is a magic xen-tools command set to help me out on Debian systems? Or a simple set of tested dd & mkfs command set for this non-lvm case?

Thanks.

xen debian disk-space-utilization

2 Answers

  1. you first have to resize the "device", then you need to expand the filesystem.

    Simple example on how to enlarge an existing file without loosing the content:

    echo 123456789 > test.txt
dd if=/dev/zero of=test.txt bs=1 seek=10 count=10
cat test.txt

    From your question it is not clear if you use the loop-device as disk, or as partition. In any case I would recommend doing the resize offline (when the disk-device is not attached to the DomU).

    • 1
  2. Best Answer

    I think it is better and simpler to append space (notice the >> operation) to the disk image

    For example, to add 1G to a disk image do:

    dd if=/dev/zero bs=1M count=1024 >> ./diskimage.img

    or if you want a sparse file

    dd if=/dev/zero bs=1 count=0 seek=1G >> diskimage.img

    To resize the file system you will then need to use a tool such as

    resize2fs <partition>

    For a detailed explanation see:

    http://grantmcwilliams.com/tech/virtualization/xen-howtos/265-resize-xen-disk-image-used-as-domu-partition

    • 0