Chapter 7. Operations on a Red Hat Gluster Storage Pod in an OpenShift Environment
This chapter lists out the various operations that can be performed on a Red Hat Gluster Storage pod (gluster pod):
- To list the pods, execute the following command :
# oc get pods
For example:# oc get pods NAME READY STATUS RESTARTS AGE storage-project-router-1-v89qc 1/1 Running 0 1d glusterfs-dc-node1.example.com 1/1 Running 0 1d glusterfs-dc-node2.example.com 1/1 Running 1 1d glusterfs-dc-node3.example.com 1/1 Running 0 1d heketi-1-k1u14 1/1 Running 0 23m rhel1 1/1 Running 0 26s
Following are the gluster pods from the above example:glusterfs-dc-node1.example.com glusterfs-dc-node2.example.com glusterfs-dc-node3.example.com
Note
The topology.json file will provide the details of the nodes in a given Trusted Storage Pool (TSP) . In the above example all the 3 Red Hat Gluster Storage nodes are from the same TSP. - To enter the gluster pod shell, execute the following command:
# oc rsh <gluster_pod_name>
For example:# oc rsh glusterfs-dc-node1.example.com sh-4.2#
- To get the peer status, execute the following command:
# gluster peer status
For example:# gluster peer status Number of Peers: 2 Hostname: node2.example.com Uuid: 9f3f84d2-ef8e-4d6e-aa2c-5e0370a99620 State: Peer in Cluster (Connected) Other names: node1.example.com Hostname: node3.example.com Uuid: 38621acd-eb76-4bd8-8162-9c2374affbbd State: Peer in Cluster (Connected)
- To list the gluster volumes on the Trusted Storage Pool, execute the following command:
# gluster volume info
For example:Volume Name: heketidbstorage Type: Distributed-Replicate Volume ID: 2fa53b28-121d-4842-9d2f-dce1b0458fda Status: Started Number of Bricks: 2 x 3 = 6 Transport-type: tcp Bricks: Brick1: 192.168.121.172:/var/lib/heketi/mounts/vg_1be433737b71419dc9b395e221255fb3/brick_c67fb97f74649d990c5743090e0c9176/brick Brick2: 192.168.121.233:/var/lib/heketi/mounts/vg_0013ee200cdefaeb6dfedd28e50fd261/brick_6ebf1ee62a8e9e7a0f88e4551d4b2386/brick Brick3: 192.168.121.168:/var/lib/heketi/mounts/vg_e4b32535c55c88f9190da7b7efd1fcab/brick_df5db97aa002d572a0fec6bcf2101aad/brick Brick4: 192.168.121.233:/var/lib/heketi/mounts/vg_0013ee200cdefaeb6dfedd28e50fd261/brick_acc82e56236df912e9a1948f594415a7/brick Brick5: 192.168.121.168:/var/lib/heketi/mounts/vg_e4b32535c55c88f9190da7b7efd1fcab/brick_65dceb1f749ec417533ddeae9535e8be/brick Brick6: 192.168.121.172:/var/lib/heketi/mounts/vg_7ad961dbd24e16d62cabe10fd8bf8909/brick_f258450fc6f025f99952a6edea203859/brick Options Reconfigured: performance.readdir-ahead: on Volume Name: vol_9e86c0493f6b1be648c9deee1dc226a6 Type: Distributed-Replicate Volume ID: 940177c3-d866-4e5e-9aa0-fc9be94fc0f4 Status: Started Number of Bricks: 2 x 3 = 6 Transport-type: tcp Bricks: Brick1: 192.168.121.168:/var/lib/heketi/mounts/vg_3fa141bf2d09d30b899f2f260c494376/brick_9fb4a5206bdd8ac70170d00f304f99a5/brick Brick2: 192.168.121.172:/var/lib/heketi/mounts/vg_7ad961dbd24e16d62cabe10fd8bf8909/brick_dae2422d518915241f74fd90b426a379/brick Brick3: 192.168.121.233:/var/lib/heketi/mounts/vg_5c6428c439eb6686c5e4cee56532bacf/brick_b3768ba8e80863724c9ec42446ea4812/brick Brick4: 192.168.121.172:/var/lib/heketi/mounts/vg_7ad961dbd24e16d62cabe10fd8bf8909/brick_0a13958525c6343c4a7951acec199da0/brick Brick5: 192.168.121.168:/var/lib/heketi/mounts/vg_17fbc98d84df86756e7826326fb33aa4/brick_af42af87ad87ab4f01e8ca153abbbee9/brick Brick6: 192.168.121.233:/var/lib/heketi/mounts/vg_5c6428c439eb6686c5e4cee56532bacf/brick_ef41e04ca648efaf04178e64d25dbdcb/brick Options Reconfigured: performance.readdir-ahead: on
- To get the volume status, execute the following command:
# gluster volume status <volname>
For example:# gluster volume status vol_9e86c0493f6b1be648c9deee1dc226a6 Status of volume: vol_9e86c0493f6b1be648c9deee1dc226a6 Gluster process TCP Port RDMA Port Online Pid ------------------------------------------------------------------------------ Brick 192.168.121.168:/var/lib/heketi/mounts/v g_3fa141bf2d09d30b899f2f260c494376/brick_9f b4a5206bdd8ac70170d00f304f99a5/brick 49154 0 Y 3462 Brick 192.168.121.172:/var/lib/heketi/mounts/v g_7ad961dbd24e16d62cabe10fd8bf8909/brick_da e2422d518915241f74fd90b426a379/brick 49154 0 Y 115939 Brick 192.168.121.233:/var/lib/heketi/mounts/v g_5c6428c439eb6686c5e4cee56532bacf/brick_b3 768ba8e80863724c9ec42446ea4812/brick 49154 0 Y 116134 Brick 192.168.121.172:/var/lib/heketi/mounts/v g_7ad961dbd24e16d62cabe10fd8bf8909/brick_0a 13958525c6343c4a7951acec199da0/brick 49155 0 Y 115958 Brick 192.168.121.168:/var/lib/heketi/mounts/v g_17fbc98d84df86756e7826326fb33aa4/brick_af 42af87ad87ab4f01e8ca153abbbee9/brick 49155 0 Y 3481 Brick 192.168.121.233:/var/lib/heketi/mounts/v g_5c6428c439eb6686c5e4cee56532bacf/brick_ef 41e04ca648efaf04178e64d25dbdcb/brick 49155 0 Y 116153 NFS Server on localhost 2049 0 Y 116173 Self-heal Daemon on localhost N/A N/A Y 116181 NFS Server on node1.example.com 2049 0 Y 3501 Self-heal Daemon on node1.example.com N/A N/A Y 3509 NFS Server on 192.168.121.172 2049 0 Y 115978 Self-heal Daemon on 192.168.121.172 N/A N/A Y 115986 Task Status of Volume vol_9e86c0493f6b1be648c9deee1dc226a6 ------------------------------------------------------------------------------ There are no active volume tasks
- To use the snapshot feature, load the snapshot module using the following command:
# - modprobe dm_snapshot
Important
Restrictions for using Snapshot- After a snapshot is created, it must be accessed though the user-serviceable snapshots feature only. This can be used to copy the old versions of files into the required location.Reverting the volume to a snapshot state is not supported and should never be done as it might damage the consistency of the data.
- On a volume with snapshots, volume changing operations, such as volume expansion, must not be performed.
- To take the snapshot of the gluster volume, execute the following command:
# gluster snapshot create <snapname> <volname>
For example:# gluster snapshot create snap1 vol_9e86c0493f6b1be648c9deee1dc226a6 snapshot create: success: Snap snap1_GMT-2016.07.29-13.05.46 created successfully
- To list the snapshots, execute the following command:
# gluster snapshot list
For example:# gluster snapshot list snap1_GMT-2016.07.29-13.05.46 snap2_GMT-2016.07.29-13.06.13 snap3_GMT-2016.07.29-13.06.18 snap4_GMT-2016.07.29-13.06.22 snap5_GMT-2016.07.29-13.06.26
- To delete a snapshot, execute the following command:
# gluster snap delete <snapname>
For example:# gluster snap delete snap1_GMT-2016.07.29-13.05.46 Deleting snap will erase all the information about the snap. Do you still want to continue? (y/n) y snapshot delete: snap1_GMT-2016.07.29-13.05.46: snap removed successfully
For more information about managing snapshots, refer https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.2/html-single/administration_guide/#chap-Managing_Snapshots. - You can set up Container Native Storage volumes for geo-replication to a non-Container Native Storage remote site. Geo-replication uses a master–slave model. Here, the Container Native Storage volume acts as the master volume. To set up geo-replication, you must run the geo-replication commands on gluster pods. To enter the gluster pod shell, execute the following command:
# oc rsh <gluster_pod_name>
For more information about setting up geo-replication, refer https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.2/html/administration_guide/chap-managing_geo-replication.
