Introduction to Red Hat Gluster Storage (GlusterFS )

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Red Hat Gluster Storage (GlusterFS )

Vikhyat UmraoSME - RHGS (GlusterFS)

Red Hat - Software Engineering Group

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Agenda

● What is Red Hat Gluster Storage?

● What is GlusterFS?

● Architecture

● Use Cases

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What is Red Hat Gluster Storage?

● Red Hat Gluster Storage is a software only, scale-out storage solution that provides flexible and unstructured data storage for the enterprise.

● GlusterFS, a key building block of Red Hat Gluster Storage, is based on a stackable user space design and can deliver exceptional performance for diverse workloads.

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What is GlusterFS?

● A general purpose scale-out distributed file system.

● Aggregates storage exports over network interconnect to provide a single unified namespace.

● Filesystem is stackable and completely in userspace.

● Layered on disk file systems that support extended attributes.

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Typical GlusterFS Deployment

● Global namespace ● Scale-out storage

building blocks● Supports thousands

of clients● Access using

GlusterFS native, NFS, SMB and HTTP protocols

● Linear performance scaling

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GlusterFS Architecture – Foundations

● Software only, runs on commodity hardware

● No external metadata servers

● Scale-out with Elasticity

● Largely POSIX compliant

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Concepts & Algorithms

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GlusterFS concepts – Trusted Storage Pool

● Trusted Storage Pool (cluster) is a collection of storage servers.

● Trusted Storage Pool is formed by invitation – “probe” a new member from the cluster and not vice versa.

● Logical partition for all data and management operations.

● Membership information used for determining quorum.

● Members can be dynamically added and removed from the pool.

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Node2

Probe

Probe accepted

Node 1 and Node 2 are peers in a trusted storage pool

Node2Node1

Node1

08/05/15 The Future of Gluster.org - John Mark Walker


Node1 Node2 Node3Node2Node1 Trusted Storage Pool

Node3Node2Node1

Detach


A brick is the combination of a node and an export directory – for e.g. hostname:/dir

Each brick inherits limits of the underlying filesystem No limit on the number bricks per node Ideally, each brick in a cluster should be of the same size

/export3/export3

/export3

Storage Node

/export1

Storage Node

/export2

/export1

/export2

/export4/export5

Storage Node

/export1

/export2

3 bricks 5 bricks 3 bricks

GlusterFS concepts - Bricks


GlusterFS concepts - Volumes

● A volume is a logical collection of bricks.

● Volume is identified by an administrator provided name.

● Volume is a mountable entity and the volume name is provided

at the time of mounting.

● mount -t glusterfs server1:/<volname> /my/mnt/point

● Bricks from the same node can be part of different volumes


GlusterFS concepts - Volumes

Node2Node1 Node3

/export/brick1

/export/brick2

/export/brick1

/export/brick2

/export/brick1

/export/brick2

music

Videos


Volume Types

● Type of a volume is specified at the time of volume creation

● Volume type determines how and where data is placed

● Following volume types are supported in glusterfs:a) Distributeb) Stripe*c) Replicationd) Distributed Replicatee) Striped Replicate*f ) Distributed Striped Replicate*

* volume types are in technology preview


Distributed Volume

● Distributes files across various bricks of the volume.

● Directories are present on all bricks of the volume.

● Single brick failure will result in loss of data availability.

● Removes the need for an external meta data server.


How does a distributed volume work?

● Uses Davies-Meyer hash algorithm.

● A 32-bit hash space is divided into N ranges for N bricks

● At the time of directory creation, a range is assigned to each

directory.

● During a file creation or retrieval, hash is computed on the file

name. This hash value is used to locate or place the file.

●Different directories in the same brick end up with different

hash ranges.








Replicated Volume

● Synchronous replication of all directory and file updates.

● Provides high availability of data when node failures

occur.

● Transaction driven for ensuring consistency.

● Changelogs maintained for re-conciliation.

● Any number of replicas can be configured.


How does a replicated volume work?


How does a replicated volume work?


Distributed Replicated Volume

● Distribute files across replicated bricks

– Number of bricks must be a multiple of the replica count

– Ordering of bricks in volume definition matters● Scaling and high availability

● Reads get load balanced.

● Most preferred model of deployment currently.


Distributed Replicated Volume


Elastic Volume Management

Application transparent operations that can be performed in

the storage layer.

● Addition of Bricks to a volume

● Remove brick from a volume

● Rebalance data spread within a volume

● Replace a brick in a volume

● Performance / Functionality tuning


FUSE based native access


NFS access


libgfapi

● Exposes APIs for accessing Gluster volumes.

● Reduces context switches.

● qemu, samba, NFS Ganesha integrated with libgfapi.


libgfapi v/s FUSE – FUSE access


libgfapi v/s FUSE – libgfapi access


Geo-Replication

● Geo-replication provides a distributed, continuous, asynchronous, and incremental replication service from one site to another over Local Area Networks (LANs), Wide Area Networks (WANs), and the Internet.

● Geo-replication uses a master–slave model, where replication and mirroring occurs between the following partners:

● Master – a Red Hat Storage volume.

● Slave – a Red Hat Storage volume. A slave volume can be either a local volume, such as localhost::volname, or a volume on a remote host, such as remote-host::volname.


Replicated Volumes vs Geo-replication


Snapshot

● Red Hat Storage Snapshot feature enables you to create point-in-time copies of Red Hat Storage volumes, which you can use to protect data.

● Users can directly access Snapshot copies which are read-only to recover from accidental deletion, corruption, or modification of the data.

● In next slide we have a diagram which will explain it in a better way :


Snapshot


Snapshot

● In previous diagram, Red Hat Gluster Storage volume consists of multiple bricks (Brick1 Brick2 etc) which is spread across one or more nodes and each brick is made up of independent thin Logical Volumes (LV).

● When a snapshot of a volume is taken, it takes the snapshot of the LV and creates another brick. Brick1_s1 is an identical image of Brick1.

● Similarly, identical images of each brick is created and these newly created bricks combine together to form a snapshot volume.


Red Hat Gluster Storage Console

● Red Hat Storage Console is management infrastructure that enables you to create a powerful, scalable storage environment.

● It provides IT departments with the tools to meet the challenges of managing complex environments, and enables administrators to reduce the cost and complexity of large deployments.

● Red Hat Storage Console includes: support to quickly create and manage Red Hat Storage trusted storage pool and volumes.


Snapshot

● Red Hat Storage Snapshot feature enables you to create point-in-time copies of Red Hat Storage volumes, which you can use to protect data. Users can directly access Snapshot copies which are read-only to recover from accidental deletion, corruption, or modification of the data.






Snapshot

● Red Hat Storage Snapshot feature enables you to create point-in-time copies of Red Hat Storage volumes, which you can use to protect data. Users can directly access Snapshot copies which are read-only to recover from accidental deletion, corruption, or modification of the data.






Red Hat Gluster Storage Monitoring

● Monitoring of Red Hat Gluster Storage servers is built on Nagios platform to monitor Red Hat Storage trusted storage pool, hosts, volumes, and services. You can monitor utilization, status, alerts and notifications for status and utilization changes.

● Using Nagios, the physical resources, logical resources, and processes (CPU, Memory, Disk, Network, Swap, cluster, volume, brick, Host, Volumes, Brick, nfs, shd, quotad, ctdb, smb, glusterd, quota, geo-replication, self-heal,and server quorum) can be monitored.

● You can view the utilization and status through Nagios Server GUI or through Trends tab of Red Hat Storage Console.


Red Hat Gluster Storage Monitoring

● Red Hat Gluster Storage trusted storage pool monitoring can be setup in of the three deployment scenarios listed below:

● Nagios deployed on Red Hat Storage node.

● Nagios deployed on Red Hat Storage Console node.

● Nagios deployed on Red Hat Enterprise Linux node.


Use Cases

● Media Storage

● Disaster Recovery (Geo-Replication)

● Efficiently and cost-effectively store virtual machine images

● Collaboration and control data access anywhere, anytime

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Q & A

Thank You

Technology

Introduction to Red Hat Gluster Storage (GlusterFS )