Mastering OpenStack - Episode 10 - Storage Decisions

Presentation By:

Roozbeh Shafiee

Autumn 2015

IRAN OpenStack Users Group

MASTERING OPENSTACK

(Episode 10)

Storage Decisions

IRAN Community| OpenStack.ir

Agenda:

• Swift (OpenStack Object Storage)

• Ceph

• Gluster

• LVM

• ZFS

• Iran OpenStack Community

OpenStack Storage Decisions


Swift (OpenStack Object Storage)



Swift (OpenStack Object Storage)

• The official OpenStack Object Store implementation

• A mature technology that has been used by Rackspace

• Used in Rackspace Cloud Files

• Highly scalable

• well-suited to managing petabytes of storage

• Better integration with OpenStack

• Better support for multiple data center deployment



Therefore…

• If you plan on distributing your storage cluster across multiple data centers

• If you need unified accounts for your users for both compute and object storage

• If you want to control your object storage with the OpenStack dashboard



Ceph



Cep Highlights

• A scalable storage solution that replicates data across commodity storage nodes

• Ceph was originally developed by one of the founders of DreamHost

• Acquired by Red Hat in 2014

• Supports object storage, block storage, and file-system interfaces

• The file-system interface is not yet considered production-ready

• Ceph supports the same API as swift for object storage and can be used as a

backend for cinder block storage as well as backend storage for glance images

• Ceph supports thin provisioning, implemented using copy-on-write.



Ceph Highlights

• Can be useful when booting from volume because a new volume can be

provisioned very quickly

• Supports keystone-based authentication

• it can be a seamless swap in for the default OpenStack swift implementation.



Ceph Advantages

• Gives administrators more fine-grained control over data distribution and

replication strategies

• Enables you to consolidate your object and block storage

• Enables very fast provisioning of boot-from-volume in- stances using thin

provisioning



An Advise For Cloud Operators

If you want to manage your object and block storage within a single system, or if

you want to support fast boot-from-volume, you should consider Ceph.



Gluster



Gluster (GFS)

• A distributed, shared file system

• You can use Gluster to consolidate your object storage and file storage into

one unified file and object storage solution, which is called Gluster For

OpenStack (GFO).

• GFO uses a customized version of swift that enables Gluster to be used as the

backend storage.



GFO vs Swift

• If you also want to support a distributed file system, either to support shared

storage live migration or to provide it as a separate service to your end users you

should consider GFO

• If you want to manage your object and file storage within a single system, you

should consider GFO.



LVM (Logical Volume Manager)



LVM (Logical Volume Manager)

The Logical Volume Manager is a Linux-based system that provides an abstraction

layer on top of physical disks to expose logical volumes to the operating system.

The LVM backend implements block storage as LVM logical partitions.

On each host that will house block storage, an administrator must initially create a

volume group dedicated to Block Storage volumes. Blocks are created from LVM

logical volumes.




LVM does not provide any replication. Typically, administrators configure RAID

on nodes that use LVM as block storage to protect against failures of individual

hard drives. However, RAID does not protect against a failure of the entire host.



ZFS



ZFS (A Solaris Based File System)

The Solaris iSCSI driver for OpenStack Block Storage implements blocks as ZFS

entities. ZFS is a file system that also has the functionality of a volume manager.

This is unlike on a Linux system, where there is a separation of volume manager

(LVM) and file system (such as, ext3, ext4, xfs, and btrfs). ZFS has a number of

advantages over ext4, including improved data-integrity checking.



ZFS on OpenStack

The ZFS backend for OpenStack Block Storage supports only Solaris-based

systems, such as Illumos. While there is a Linux port of ZFS, it is not included in

any of the standard Linux distributions, and it has not been tested with OpenStack

Block Storage. As with LVM, ZFS does not provide replication across hosts on its

own; you need to add a replication solution on top of ZFS if your cloud needs to

be able to handle storage-node failures.




We do not recommend ZFS unless you have previous experience with deploying it,

since the ZFS backend for Block Storage requires a Solaris-based operating system,

and we assume that your experience is primarily with Linux-based systems.



Iran OpenStack Community



Stay in Touch and Join Us:

• Home Page: OpenStack.ir

• Meetup Page: Meetup.com/Iran-OpenStack

• Mailing List: [email protected]

• Twitter: @OpenStackIR , #OpenStackIRAN

• IRC Channel on FreeNode: #OpenStack-ir


Roozbeh Shafiee

Iran OpenStack Community Manager

[email protected]

OpenStack.ir

Thank You

We need to work together to build a better community

Technology

Mastering OpenStack - Episode 10 - Storage Decisions