From 19679279717d26662adaf7706589c9a1fc1634a4 Mon Sep 17 00:00:00 2001 From: Bill Owen Date: Tue, 17 Sep 2013 14:39:41 -0700 Subject: [PATCH] GPFS Cinder Volume Driver documentation. This is the initial version of GPFS cinder driver documentatation for avana release. Update to use included config flag table. Change-Id: I923e4525ce6a9b1277f3571ad5a0ca03785a57b5 --- .../drivers/ibm-gpfs-volume-driver.xml | 153 ++++++++++++++++++ .../block-storage/section_volume-drivers.xml | 1 + 2 files changed, 154 insertions(+) create mode 100644 doc/config-reference/block-storage/drivers/ibm-gpfs-volume-driver.xml diff --git a/doc/config-reference/block-storage/drivers/ibm-gpfs-volume-driver.xml b/doc/config-reference/block-storage/drivers/ibm-gpfs-volume-driver.xml new file mode 100644 index 0000000000..ac3e437c21 --- /dev/null +++ b/doc/config-reference/block-storage/drivers/ibm-gpfs-volume-driver.xml @@ -0,0 +1,153 @@ +
+ IBM GPFS Volume Driver + The General Parallel File System (GPFS) is a cluster file system that provides concurrent + access to file systems from multiple nodes. The storage provided by these nodes can be + direct attached, network attached, SAN attached or a combination of these methods. GPFS + provides many features beyond common data access including data replication, policy based + storage management, and space efficient file snapshot and clone operations. +
+ How the GPFS Driver Works + This driver enables the use of GPFS in a similar fashion as the NFS driver. With the + GPFS driver, instances do not actually access a storage device at the block level. + Instead, volume backing files are created in a GPFS file system and mapped to instances, + which emulate a block device. + + + GPFS software must be installed and running on nodes where Cinder volume and + Nova compute services are running in the OpenStack environment. A GPFS file + system must also be created and mounted on these nodes before starting the + cinder-volume service. The details of these GPFS specific + steps are covered in GPFS Administration documentation. + + + Optionally, Glance can be configured to store images on a GPFS file system. When + Cinder volumes are created from Glance images, if both image and volume data reside in + the same GPFS file system, the data from image files is moved efficiently to Cinder + volumes using copy on write optimization strategy. +
+
+ Enabling the GPFS Driver + To use Cinder with the GPFS driver, first set the volume_driver in + cinder.conf: + volume_driver = cinder.volume.drivers.gpfs.GPFSDriver + The following table contains the configuration options supported by the GPFS + driver. + + + The flag gpfs_images_share_mode is only valid if the Image service + is configured to use GPFS with gpfs_images_dir flag. Also note, + when the value of this flag is copy_on_write, the paths + specified by the flags gpfs_mount_point_base and + gpfs_images_dir must both reside in the same GPFS file system + and in the same GPFS fileset. + + +
+
+ Volume Creation Options + It is possible to specify additional volume configuration options on a per-volume + basis by specifiying volume metadata. The volume is created using the specified options. + Changing the metadata after the volume is created has no effect. The following table + lists the volume creation options supported by the GPFS volume driver. + + List of Volume Creation Options for GPFS Volume Driver: + + + + + + Metadata Item Name + Description + + + + + fstype + The driver will create a file system or swap area on the new volume. + If fstype=swap is specified, the mkswap command is + used to create a swap area. Otherwise the mkfs command is passed the + specified type, for example ext3, ext4, etc. + + + fslabel + The driver will set the file system label for the file system + specified by fstype option. This value is only used if fstype is + specified. + + + data_pool_name + + The driver will assign the volume file to the specified GPFS + storage pool. Note that the GPFS storage pool must already be + created. + + + + replicas + + Specify how many copies of the volume file to create. Valid values + are 1, 2, and, for GPFS V3.5.0.7 and later, 3. This value cannot be + greater than the value of the MaxDataReplicas attribute of the file + system. + + + + dio + + Enable or disable the Direct I/O caching policy for the volume + file. Valid values are "yes" and "no". + + + + write_affinity_depth + + Specify the allocation policy to be used for the volume file. Note + that this option only works if "allow-write-affinity" is set for the + GPFS data pool. + + + + block_group_factor + + Specify how many blocks are laid out sequentially in the volume + file to behave like a single large block. This option only works if + "allow-write-affinity" is set for the GPFS data pool. + + + + write_affinity_failure_group + + Specify the range of nodes (in GPFS shared nothing architecture) + where replicas of blocks in the volume file are to be written. See + GPFS Administration and Programming Reference guide for more details + on this option. + + + + +
+ + Example Using Volume Creation Options + This example shows the creation of a 50GB volume with an ext4 filesystem labeled + newfsand direct IO enabled: + $cinder create --metadata fstype=ext4 fslabel=newfs dio=yes --display-name volume_1 50 + +
+
+ Operational Notes for GPFS Driver + + Snapshots and Clones + Volume snapshots are implemented using the GPFS file clone feature. Whenever a new + snapshot is created, the snapshot file is efficiently created as a read-only clone + parent of the volume, and the volume file uses copy on write optimization strategy + to minimize data movement. + Similarly when a new volume is created from a snapshot or from an existing volume, + the same approach is taken. The same approach is also used when a new volume is + created from a Glance image, if the source image is in raw format, and + gpfs_images_share_mode is set to + copy_on_write. + +
+
diff --git a/doc/config-reference/block-storage/section_volume-drivers.xml b/doc/config-reference/block-storage/section_volume-drivers.xml index 347e67bf49..e636e57450 100644 --- a/doc/config-reference/block-storage/section_volume-drivers.xml +++ b/doc/config-reference/block-storage/section_volume-drivers.xml @@ -21,6 +21,7 @@ iscsi_helper=tgtadm +