%BOOK_ENTITIES; ]> A volume is a logical collection of bricks where each brick is an export directory on a server in the trusted storage pool. Most of the gluster management operations are performed on the volume. To create a new volume in your storage environment, specify the bricks that comprise the volume. After you have created a new volume, you must start it before attempting to mount it. Volumes of the following types can be created in your storage environment: Distributed - Distributed volumes distributes files throughout the bricks in the volume. You can use distributed volumes where the requirement is to scale storage and the redundancy is either not important or is provided by other hardware/software layers. For more information, see . Replicated – Replicated volumes replicates files across bricks in the volume. You can use replicated volumes in environments where high-availability and high-reliability are critical. For more information, see . Striped – Striped volumes stripes data across bricks in the volume. For best results, you should use striped volumes only in high concurrency environments accessing very large files. For more information, see . Distributed Striped - Distributed striped volumes stripe data across two or more nodes in the cluster. You should use distributed striped volumes where the requirement is to scale storage and in high concurrency environments accessing very large files is critical. For more information, see . Distributed Replicated - Distributed replicated volumes distributes files across replicated bricks in the volume. You can use distributed replicated volumes in environments where the requirement is to scale storage and high-reliability is critical. Distributed replicated volumes also offer improved read performance in most environments. For more information, see . Distributed Striped Replicated – Distributed striped replicated volumes distributes striped data across replicated bricks in the cluster. For best results, you should use distributed striped replicated volumes in highly concurrent environments where parallel access of very large files and performance is critical. In this release, configuration of this volume type is supported only for Map Reduce workloads. For more information, see . Striped Replicated – Striped replicated volumes stripes data across replicated bricks in the cluster. For best results, you should use striped replicated volumes in highly concurrent environments where there is parallel access of very large files and performance is critical. In this release, configuration of this volume type is supported only for Map Reduce workloads. For more information, see . To create a new volume Create a new volume : # gluster volume create NEW-VOLNAME [stripe COUNT | replica COUNT] [transport tcp | rdma | tcp, rdma] NEW-BRICK1 NEW-BRICK2 NEW-BRICK3... For example, to create a volume called test-volume consisting of server3:/exp3 and server4:/exp4: # gluster volume create test-volume server3:/exp3 server4:/exp4 Creation of test-volume has been successful Please start the volume to access data.

In a distributed volumes files are spread randomly across the bricks in the volume. Use distributed volumes where you need to scale storage and redundancy is either not important or is provided by other hardware/software layers. Disk/server failure in distributed volumes can result in a serious loss of data because directory contents are spread randomly across the bricks in the volume.

To create a distributed volume Create a trusted storage pool as described earlier in . Create the distributed volume: # gluster volume create NEW-VOLNAME [transport tcp | rdma | tcp,rdma] NEW-BRICK... For example, to create a distributed volume with four storage servers using tcp: # gluster volume create test-volume server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 Creation of test-volume has been successful Please start the volume to access data. (Optional) You can display the volume information: # gluster volume info Volume Name: test-volume Type: Distribute Status: Created Number of Bricks: 4 Transport-type: tcp Bricks: Brick1: server1:/exp1 Brick2: server2:/exp2 Brick3: server3:/exp3 Brick4: server4:/exp4 For example, to create a distributed volume with four storage servers over InfiniBand: # gluster volume create test-volume transport rdma server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 Creation of test-volume has been successful Please start the volume to access data. If the transport type is not specified, tcp is used as the default. You can also set additional options if required, such as auth.allow or auth.reject. For more information, see Make sure you start your volumes before you try to mount them or else client operations after the mount will hang, see for details.

Replicated volumes create copies of files across multiple bricks in the volume. You can use replicated volumes in environments where high-availability and high-reliability are critical. The number of bricks should be equal to of the replica count for a replicated volume. To protect against server and disk failures, it is recommended that the bricks of the volume are from different servers.

To create a replicated volume Create a trusted storage pool as described earlier in . Create the replicated volume: # gluster volume create NEW-VOLNAME [replica COUNT] [transport tcp | rdma tcp,rdma] NEW-BRICK... For example, to create a replicated volume with two storage servers: # gluster volume create test-volume replica 2 transport tcp server1:/exp1 server2:/exp2 Creation of test-volume has been successful Please start the volume to access data. If the transport type is not specified, tcp is used as the default. You can also set additional options if required, such as auth.allow or auth.reject. For more information, see Make sure you start your volumes before you try to mount them or else client operations after the mount will hang, see for details.

Striped volumes stripes data across bricks in the volume. For best results, you should use striped volumes only in high concurrency environments accessing very large files. The number of bricks should be a equal to the stripe count for a striped volume.

To create a striped volume Create a trusted storage pool as described earlier in . Create the striped volume: # gluster volume create NEW-VOLNAME [stripe COUNT] [transport tcp | rdma | tcp,rdma] NEW-BRICK... For example, to create a striped volume across two storage servers: # gluster volume create test-volume stripe 2 transport tcp server1:/exp1 server2:/exp2 Creation of test-volume has been successful Please start the volume to access data. If the transport type is not specified, tcp is used as the default. You can also set additional options if required, such as auth.allow or auth.reject. For more information, see Make sure you start your volumes before you try to mount them or else client operations after the mount will hang, see for details.

Distributed striped volumes stripes files across two or more nodes in the cluster. For best results, you should use distributed striped volumes where the requirement is to scale storage and in high concurrency environments accessing very large files is critical. The number of bricks should be a multiple of the stripe count for a distributed striped volume.

To create a distributed striped volume Create a trusted storage pool as described earlier in . Create the distributed striped volume: # gluster volume create NEW-VOLNAME [stripe COUNT] [transport tcp | rdma | tcp,rdma] NEW-BRICK... For example, to create a distributed striped volume across eight storage servers: # gluster volume create test-volume stripe 4 transport tcp server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 server5:/exp5 server6:/exp6 server7:/exp7 server8:/exp8 Creation of test-volume has been successful Please start the volume to access data. If the transport type is not specified, tcp is used as the default. You can also set additional options if required, such as auth.allow or auth.reject. For more information, see Make sure you start your volumes before you try to mount them or else client operations after the mount will hang, see for details.

Distributes files across replicated bricks in the volume. You can use distributed replicated volumes in environments where the requirement is to scale storage and high-reliability is critical. Distributed replicated volumes also offer improved read performance in most environments. The number of bricks should be a multiple of the replica count for a distributed replicated volume. Also, the order in which bricks are specified has a great effect on data protection. Each replica_count consecutive bricks in the list you give will form a replica set, with all replica sets combined into a volume-wide distribute set. To make sure that replica-set members are not placed on the same node, list the first brick on every server, then the second brick on every server in the same order, and so on.

To create a distributed replicated volume Create a trusted storage pool as described earlier in . Create the distributed replicated volume: # gluster volume create NEW-VOLNAME [replica COUNT] [transport tcp | rdma | tcp,rdma] NEW-BRICK... For example, four node distributed (replicated) volume with a two-way mirror: # gluster volume create test-volume replica 2 transport tcp server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 Creation of test-volume has been successful Please start the volume to access data. For example, to create a six node distributed (replicated) volume with a two-way mirror: # gluster volume create test-volume replica 2 transport tcp server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 server5:/exp5 server6:/exp6 Creation of test-volume has been successful Please start the volume to access data. If the transport type is not specified, tcp is used as the default. You can also set additional options if required, such as auth.allow or auth.reject. For more information, see Make sure you start your volumes before you try to mount them or else client operations after the mount will hang, see for details.

Distributed striped replicated volumes distributes striped data across replicated bricks in the cluster. For best results, you should use distributed striped replicated volumes in highly concurrent environments where parallel access of very large files and performance is critical. In this release, configuration of this volume type is supported only for Map Reduce workloads. The number of bricks should be a multiples of number of stripe count and replica count for a distributed striped replicated volume. To create a distributed striped replicated volume Create a trusted storage pool as described earlier in . Create a distributed striped replicated volume using the following command: # gluster volume create NEW-VOLNAME [stripe COUNT] [replica COUNT] [transport tcp | rdma | tcp,rdma] NEW-BRICK... For example, to create a distributed replicated striped volume across eight storage servers: # gluster volume create test-volume stripe 2 replica 2 transport tcp server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 server5:/exp5 server6:/exp6 server7:/exp7 server8:/exp8 Creation of test-volume has been successful Please start the volume to access data. If the transport type is not specified, tcp is used as the default. You can also set additional options if required, such as auth.allow or auth.reject. For more information, see Make sure you start your volumes before you try to mount them or else client operations after the mount will hang, see for details.

Striped replicated volumes stripes data across replicated bricks in the cluster. For best results, you should use striped replicated volumes in highly concurrent environments where there is parallel access of very large files and performance is critical. In this release, configuration of this volume type is supported only for Map Reduce workloads. The number of bricks should be a multiple of the replicate count and stripe count for a striped replicated volume.

To create a striped replicated volume Create a trusted storage pool consisting of the storage servers that will comprise the volume. For more information, see . Create a striped replicated volume : # gluster volume create NEW-VOLNAME [stripe COUNT] [replica COUNT] [transport tcp | rdma | tcp,rdma] NEW-BRICK... For example, to create a striped replicated volume across four storage servers: # gluster volume create test-volume stripe 2 replica 2 transport tcp server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 Creation of test-volume has been successful Please start the volume to access data. To create a striped replicated volume across six storage servers: # gluster volume create test-volume stripe 3 replica 2 transport tcp server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 server5:/exp5 server6:/exp6 Creation of test-volume has been successful Please start the volume to access data. If the transport type is not specified, tcp is used as the default. You can also set additional options if required, such as auth.allow or auth.reject. For more information, see Make sure you start your volumes before you try to mount them or else client operations after the mount will hang, see for details.

You must start your volumes before you try to mount them. To start a volume Start a volume: # gluster volume start VOLNAME For example, to start test-volume: # gluster volume start test-volume Starting test-volume has been successful