openstack/openstack-manuals
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Merge "Added Thin/Thick description to VMDK driver section"

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Jenkins 2015-06-20 16:22:37 +00:00 committed by Gerrit Code Review
commit 5eb4cf310d
1 changed files with 27 additions and 11 deletions
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doc/config-reference/block-storage/drivers/vmware-vmdk-driver.xml
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@ -55,14 +55,31 @@
</section> </section>
<section xml:id="vmdk_disk_type"> <section xml:id="vmdk_disk_type">
<title>VMDK disk type</title> <title>VMDK disk type</title>
<para>The VMware VMDK drivers support the creation of VMDK <para>The VMware VMDK drivers support the creation of VMDK disk file
disk files of type <literal>thin</literal>, types <literal>thin</literal>, <literal>lazyZeroedThick</literal>
<literal>lazyZeroedThick</literal>, or (sometimes called thick or flat), or <literal>eagerZeroedThick</literal>.
<literal>eagerZeroedThick</literal>. Use the </para>
<code>vmware:vmdk_type</code> extra spec key with the <para>
appropriate value to specify the VMDK disk file type. The A thin virtual disk is allocated and zeroed on demand as the space
following table captures the mapping between the extra is used. Unused space on a Thin disk is available to other users.
spec entry and the VMDK disk file type:</para> </para>
<para>
A lazy zeroed thick virtual disk will have all space allocated at
disk creation. This reserves the entire disk space, so it is not
available to other users at any time.
</para>
<para>
An eager zeroed thick virtual disk is similar to a lazy zeroed thick
disk, in that the entire disk is allocated at creation. However, in
this type, any previous data will be wiped clean on the disk before
the write. This can mean that the disk will take longer to create,
but can also prevent issues with stale data on physical media.
</para>
<para>
Use the <literal>vmware:vmdk_type</literal> extra spec key with the
appropriate value to specify the VMDK disk file type. This table
shows the mapping between the extra spec entry and the VMDK disk
file type:</para>
<table rules="all"> <table rules="all">
<caption>Extra spec entry to VMDK disk file type <caption>Extra spec entry to VMDK disk file type
mapping</caption> mapping</caption>
@ -91,9 +108,8 @@
</tr> </tr>
</tbody> </tbody>
</table> </table>
<para>If you do not specify a <code>vmdk_type</code> extra <para>If you do not specify a <code>vmdk_type</code> extra spec entry,
spec entry, the default disk file type is the disk file type will default to <literal>thin</literal>.</para>
<literal>thin</literal>.</para>
<para>The following example shows how to create a <para>The following example shows how to create a
<code>lazyZeroedThick</code> VMDK volume by using the <code>lazyZeroedThick</code> VMDK volume by using the
appropriate <code>vmdk_type</code>:</para> appropriate <code>vmdk_type</code>:</para>