Key concepts
Share
In the Shared File Systems service share is the fundamental resource unit
allocated by the Shared File System service. It represents an allocation of a
persistent, readable, and writable filesystems. Compute instances access these
filesystems. Depending on the deployment configuration, clients outside of
OpenStack can also access the filesystem.
Note
A share is an abstract storage object that may or may not directly
map to a “share” concept from the underlying storage provider.
See the description of share instance for more details.
Share instance
This concept is tied with share and represents created resource on specific
back end, when share represents abstraction between end user and
back-end storages. In common cases, it is one-to-one relation.
One single share has more than one share instance in two cases:
Therefore, each share instance stores information specific to real
allocated resource on storage. And share represents the information
that is common for share instances.
A user with member role will not be able to work with it directly. Only
a user with admin role has rights to perform actions against specific
share instances.
Snapshot
A snapshot is a point-in-time, read-only copy of a share. You can
create Snapshots from an existing, operational share regardless
of whether a client has mounted the file system. A snapshot
can serve as the content source for a new share. Specify the
Create from snapshot option when creating a new share on the
dashboard.
Storage Pools
With the Kilo release of OpenStack, Shared File Systems can use
storage pools. The storage may present one or more logical storage
resource pools that the Shared File Systems service
will select as a storage location when provisioning shares.
Share Type
Share type is an abstract collection of criteria used to characterize
shares. They are most commonly used to create a hierarchy of functional
capabilities. This hierarchy represents tiered storage services levels. For
example, an administrator might define a premium share type that
indicates a greater level of performance than a basic share type.
Premium represents the best performance level.
Share Access Rules
Share access rules define which users can access a particular share.
For example, administrators can declare rules for NFS shares by
listing the valid IP networks which will access the share. List the
IP networks in CIDR notation.
Security Services
Security services allow granular client access rules for
administrators. They can declare rules for authentication or
authorization to access share content. External services including LDAP,
Active Directory, and Kerberos can be declared as resources. Examine and
consult these resources when making an access decision for a
particular share. You can associate Shares with multiple
security services, but only one service per one type.
Share Networks
A share network is an object that defines a relationship between a
project network and subnet, as defined in an OpenStack Networking service or
Compute service. The share network is also defined in shares
created by the same project. A project may find it desirable to
provision shares such that only instances connected to a particular
OpenStack-defined network have access to the share. Also,
security services can be attached to share networks,
because most of auth protocols require some interaction with network services.
The Shared File Systems service has the ability to work outside of OpenStack.
That is due to the StandaloneNetworkPlugin. The plugin is compatible with
any network platform, and does not require specific network services in
OpenStack like Compute or Networking service. You can set the network
parameters in the manila.conf file.
Share Servers
A share server is a logical entity that hosts the shares created
on a specific share network. A share server may be a
configuration object within the storage controller, or it may represent
logical resources provisioned within an OpenStack deployment used to
support the data path used to access shares.
Share servers interact with network services to determine the appropriate
IP addresses on which to export shares according to the related share
network. The Shared File Systems service has a pluggable network model that
allows share servers to work with different implementations of
the Networking service.
