1.
Presentation By:
Roozbeh Shafiee
Autumn 2015
IRAN OpenStack Users Group
MASTERING
OPENSTACK
(Episode 08)
Storage Decisions

2.
IRAN Community| OpenStack.ir
Agenda:
●
Storage Types
●
Storage Specifications
●
Iran OpenStack Community
OpenStack Storage Decisions

3.
IRAN Community| OpenStack.ir
Storage Types
OpenStack Storage Decisions

4.
IRAN Community| OpenStack.ir
Storage Types
Storage is found in many parts of the OpenStack stack, and the differing types can
cause confusion to even experienced cloud engineers.
This section focuses on persistent storage options you can configure with your
cloud. It’s important to understand the distinction between ephemeral storage
and persistent storage.
OpenStack Storage Decisions

5.
IRAN Community| OpenStack.ir
Ephemeral Storage
If you deploy only the OpenStack Compute Service (nova), your users do not have
access to any form of persistent storage by default.
The disks associated with VMs are “ephemeral,” meaning that they effectively
disappear when a virtual machine is terminated.
OpenStack Storage Decisions

6.
IRAN Community| OpenStack.ir
Persistent Storage
Persistent storage means that the storage resource outlives any other resource
and is always available, regardless of the state of a running instance.
Today, OpenStack clouds explicitly support two types of persistent storage:
●
Object Storage
●
Block Storage
OpenStack Storage Decisions

7.
IRAN Community| OpenStack.ir
Storage Specifications
OpenStack Storage Decisions

8.
IRAN Community| OpenStack.ir
Ephemeral Storage
●
Used to: Run operating system and scratch space
●
Accessed through: A file system (XFS, EXT4, BTRFS)
●
Accessible from: Within a VM
●
Managed by: OpenStack Compute (nova)
●
Persists until: VM is terminated
●
Sizing determined by: Administrator configuration of size settings
●
Example of typical usage: 10 GB first disk, 30 GB second disk
OpenStack Storage Decisions

9.
IRAN Community| OpenStack.ir
Block Storage
●
Used to: Add additional persistent storage to a virtual machine (VM)
●
Accessed through: A block device that can be partitioned, formatted & mounted
●
Accessible from: Within a VM
●
Managed by: OpenStack Block Storage (cinder)
●
Persists until: Deleted by user
●
Sizing determined by: User specification in initial request
●
Example of typical usage: 1 TB Disk
OpenStack Storage Decisions

10.
IRAN Community| OpenStack.ir
Object Storage
●
Used to: Store data, including VM images
●
Accessed through: The REST API
●
Accessible from: Anywhere
●
Managed by: OpenStack Object Storage (swift)
●
Persists until: Deleted by user
●
Sizing determined by: Amount of available physical storage
●
Example of typical usage: 10s of TBs of dataset storage
OpenStack Storage Decisions

11.
IRAN Community| OpenStack.ir
File-level Storage (for Live Migration)
With file-level storage, users access stored data using the operating system’s
file system interface. Most users, if they have used a network storage solution
before, have encountered this form of networked storage. In the Unix world, the
most common form of this is NFS. In the Windows world, the most common form
is called CIFS (previously, SMB).
OpenStack Storage Decisions

12.
IRAN Community| OpenStack.ir
File-level Storage (for Live Migration)
OpenStack clouds do not present file-level storage to end users. However, it is
important to consider file-level storage for storing instances under
/var/lib/nova/instances
when designing your cloud, since you must have a shared file system if you want
to support live migration.
OpenStack Storage Decisions

13.
Roozbeh Shafiee
Iran OpenStack Community Manager
Roozbeh@OpenStack.ir
OpenStack.ir
Thank You
We need to work together to build a better community