Merge pull request #147 from shapeblue/sec_stg_mgmt
secondary storage management
diff --git a/source/adminguide/storage.rst b/source/adminguide/storage.rst
index 987dd5f..9757d45 100644
--- a/source/adminguide/storage.rst
+++ b/source/adminguide/storage.rst
@@ -29,7 +29,7 @@
---------------
This section gives technical details about CloudStack
-primary storage. For more information about the concepts behind primary storage
+primary storage. For more information about the concepts behind primary storage
see :ref:`about-primary-storage` . For information about how to install and configure
primary storage through the CloudStack UI, see the in the Installation Guide.
@@ -183,6 +183,28 @@
secondary storage through the CloudStack UI, see the Advanced
Installation Guide. about-secondary-storage>`_
+Migration of data between secondary storages is now supported. One may choose
+to completely migrate the data or migrate data such that the stores
+are balanced by choosing the appropriate Migration Policy. In order to facilitate
+distributing the migration load, SSVMs are spawned up if a file transfer takes
+more than a defined threshold. Following are the Global setting values to one may
+want to look at before proceeding with the migration task:
+
+
+ +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+ | Configuration Parameters | Description |
+ +==================================+========================================================================================================================================================================+
+ | image.store.imbalance.threshold | The storage imbalance threshold that is compared with the standard deviation percentage for a storage utilization metric. The value is a percentage in decimal format. |
+ +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+ | secstorage.max.migrate.sessions | The max number of concurrent copy command execution sessions that an SSVM can handle |
+ +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+ | max.ssvm.count | Number of additional SSVMs to handle migration of data objects concurrently |
+ +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+ | max.data.migration.wait.time | Maximum wait time for a data migration task before spawning a new SSVM |
+ +----------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+
+Secondary storages can also be set to read-only in order to cordon it off
+from being used for storing any further templates, volumes and snapshots.
Working With Volumes
--------------------
@@ -208,7 +230,7 @@
template creation. Volumes are hypervisor-specific: a volume from one
hypervisor type may not be used on a guest of another hypervisor type.
-.. note::
+.. note::
CloudStack supports attaching up to
- 13 data disks on XenServer hypervisor versions 6.0 and above,
@@ -386,9 +408,9 @@
Detaching and Moving Volumes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-.. note::
- This procedure is different from moving volumes from one storage pool
- to another as described in `“VM Storage Migration”
+.. note::
+ This procedure is different from moving volumes from one storage pool
+ to another as described in `“VM Storage Migration”
<#vm-storage-migration>`_.
A volume can be detached from a guest VM and attached to another guest.
@@ -417,9 +439,9 @@
Supported in XenServer, KVM, and VMware.
-.. note::
- This procedure is different from moving disk volumes from one VM to
- another as described in `“Detaching and Moving Volumes”
+.. note::
+ This procedure is different from moving disk volumes from one VM to
+ another as described in `“Detaching and Moving Volumes”
<#detaching-and-moving-volumes>`_.
You can migrate a virtual machine’s root disk volume or any additional
@@ -440,10 +462,10 @@
migrate a VM’s disks from one storage repository to another, all while
the VM is running.
-.. note::
- Because of a limitation in VMware, live migration of storage for a
- VM is allowed only if the source and target storage pool are
- accessible to the source host; that is, the host where the VM is
+.. note::
+ Because of a limitation in VMware, live migration of storage for a
+ VM is allowed only if the source and target storage pool are
+ accessible to the source host; that is, the host where the VM is
running when the live migration operation is requested.
@@ -475,7 +497,7 @@
Moving Volumes” <#detaching-and-moving-volumes>`_ but skip the “reattach”
step at the end. You will do that after migrating to new storage.
-#. Click the Migrate Volume button |Migrateinstance.png| and choose the
+#. Click the Migrate Volume button |Migrateinstance.png| and choose the
destination from the dropdown list.
#. Watch for the volume status to change to Migrating, then back to
@@ -491,7 +513,7 @@
Moving Volumes” <#detaching-and-moving-volumes>`_ but skip the “reattach”
step at the end. You will do that after migrating to new storage.
-#. Click the Migrate Volume button |Migrateinstance.png| and choose the
+#. Click the Migrate Volume button |Migrateinstance.png| and choose the
destination from the dropdown list.
#. Watch for the volume status to change to Migrating, then back to
@@ -520,12 +542,12 @@
#. (KVM only) Stop the VM.
-#. Click the Migrate button |Migrateinstance.png| and choose the
+#. Click the Migrate button |Migrateinstance.png| and choose the
destination from the dropdown list.
- .. note::
- If the VM's storage has to be migrated along with the VM, this will
- be noted in the host list. CloudStack will take care of the storage
+ .. note::
+ If the VM's storage has to be migrated along with the VM, this will
+ be noted in the host list. CloudStack will take care of the storage
migration for you.
#. Watch for the volume status to change to Migrating, then back to
@@ -806,10 +828,10 @@
properties file (\*.ova.meta) which it stored along with the original
snapshot data.
-.. note::
- For upgrading customers: This process applies only to newly created
- snapshots after upgrade to CloudStack 4.2. Snapshots that have already
- been taken and stored in OVA format will continue to exist in that
+.. note::
+ For upgrading customers: This process applies only to newly created
+ snapshots after upgrade to CloudStack 4.2. Snapshots that have already
+ been taken and stored in OVA format will continue to exist in that
format, and will continue to work as expected.
@@ -826,4 +848,4 @@
.. |Migrateinstance.png| image:: /_static/images/migrate-instance.png
:alt: button to migrate a volume.
.. |volume-from-snap.PNG| image:: /_static/images/volume-from-snap.PNG
- :alt: Offering is needed when creating a volume from the ROOT volume snapshot.
+ :alt: Offering is needed when creating a volume from the ROOT volume snapshot.