The purpose of this article is to provide a step-by-step guide for installing and configuring a simple two-node GPFS cluster on AIX. The following diagram provides a visual representation of the cluster configuration.
Figure 1. Visual representation of the cluster configuration
GPFS provides a true “shared file system” capability, with excellent performance and scalability. GPFS allows concurrent access for a group of computers to a common set of file data over a common storage area network (SAN) infrastructure, a network, or a mix of connection types. GPFS provides storage management, information lifecycle management tools, and centralized administration and allows for shared access to file systems from remote GPFS clusters providing a global namespace.
GPFS offers data tiering, replication, and many other advanced features. The configuration can be as simple or complex as you want.
Preparing the AIX environment for GPFS
We’ll assume that you have already purchased the necessary licenses and software for GPFS. With a copy of the GPFS software available, copy the GPFS file sets to each of the AIX nodes on which you need to run GPFS.
In this article, each partition was built with AIX version 7.1, Technology Level 2, Service Pack 1:
#oslevel ‑s 7100‑02‑01‑1245
Each AIX system is configured with seven SAN disks. One disk is used for the AIX operating system (rootvg) and the remaining six disks are used by GPFS.
#lspv hdisk0 00c334b6af00e77b rootvg active hdisk1 none none hdisk2 none none hdisk3 none none hdisk4 none none hdisk5 none none hdisk6 none none
The SAN disks (to be used with GPFS) are assigned to both nodes (that is, they are shared between both partitions). Both AIX partitions are configured with virtual Fibre Channel adapters and access their shared storage through the SAN, as shown in the following figure.
Figure 2. Deployment diagram
The following attributes, shown in the table below, were changed for each hdisk, using the
|AIX device name||Size in GB||AIX disk device type||Algorithm||queue_depth||reserve_policy|
|hdisk0||50||Hitachi MPIO Disk VSP||round_robin||32||no_reserve|
|hdisk1||50||Hitachi MPIO Disk VSP||round_robin||32||no_reserve|
|hdisk2||50||Hitachi MPIO Disk VSP||round_robin||32||no_reserve|
|hdisk3||50||Hitachi MPIO Disk VSP||round_robin||32||no_reserve|
|hdisk4||50||Hitachi MPIO Disk VSP||round_robin||32||no_reserve|
|hdisk5||50||Hitachi MPIO Disk VSP||round_robin||32||no_reserve|
|hdisk6||50||Hitachi MPIO Disk VSP||round_robin||32||no_reserve|
lsattr command can be used to verify that each attribute is set to the correct value:
#lsattr ‑El hdisk6 –a queue_depth –q algorithm –a reserve_policy algorithm round_robin Algorithm True queue_depth 32 Queue DEPTH True reserve_policy no_reserve Reserve Policy True
The next step is to configure Secure Shell (SSH) so that both nodes can communicate with each other. When building a GPFS cluster, you must ensure that the nodes in the cluster have SSH configured correctly so that they do not require password authentication. This requires the configuration of Rivest-Shamir-Adleman algorithm (RSA) key pairs for the root users SSH configuration. This configuration needs to be configured in both directions, to all nodes in the GPFS cluster.
mm commands in GPFS require authentication in order for them to work. If the keys are not configured correctly, the commands will prompt for the root password each time and the GPFS cluster might fail. A good way to test this is to ensure that the
ssh command can work unhindered by a request for the roots password.
You can refer to the step-by-step guide for configuring SSH keys on AIX:
You can confirm that the nodes can communicate with each other (unhindered) using
SSH with the following commands on each node:
aixlpar1#ssh aixlpar1a date aixlpar1#ssh aixlpar2a date aixlpar2#ssh aixlpar2a date aixlpar2#ssh aixlpar1a date
With SSH working, configure the WCOLL (Working Collective) environment variable for the root user. For example, create a text file that lists each of the nodes, one per line:
#vi /usr/local/etc/gfps‑nodes.list aixlpar1a aixlpar2a
Copy the node file to all nodes in the cluster.
Add the following entry to the root users .kshrc file. This will allow the root user to execute commands on all nodes in the GPFS cluster using the
The root users PATH should be modified to ensure that all GPFS
mm commands are available to the system administrator. Add the following entry to the root user’s .kshrc file.
The /etc/hosts file should be consistent across all nodes in the GPFS cluster. Each IP address for each node must be added to/etc/hosts on each cluster node. This is recommended, even when Domain Name System (DNS) is configured on each node. For example:
#GPFS_CLUSTER1 Cluster ‑ Test ##GPFS Admin network ‑ en0 10.1.5.110 aixlpar1a aixlpar1 10.1.5.120 aixlpar2a aixlpar2 ##GPFS Daemon ‑ Private Network – en1 10.1.7.110 aixlpar1p 10.1.7.120 aixlpar2p
Installing GPFS on AIX
Now that the AIX environment is configured, the next step is to install the GPFS software on each node. This is a very straightforward process.
We will install GPFS version 3.5 (base-level file sets) and then apply the latest updates to bring the level up to 188.8.131.52. There are only three file sets to install. You can use System Management Interface Tool (SMIT) or the
installp command to install the software.
aixlpar1 : /tmp/cg/GPFS/gpfs35_aix #inutoc . aixlpar1 : /tmp/cg/GPFS/gpfs35_aix #ls ‑ltr total 123024 ‑rw‑r‑‑r‑‑ 1 root system 175104 Jun 7 2012 gpfs.msg.en_US ‑rw‑r‑‑r‑‑ 1 root system 868352 Jun 7 2012 gpfs.docs.data ‑rw‑r‑‑r‑‑ 1 root system 61939712 Jun 7 2012 gpfs.base ‑rw‑r‑‑r‑‑ 1 root system 3549 Apr 26 16:37 .toc aixlpar1 : /tmp/cg/GPFS/gpfs35_aix #install –Y –d . ALL
Repeat this operation on the second node.
You can verify that the base-level GPFS file sets are installed by using the
#lslpp ‑l | grep ‑i gpfs gpfs.base 184.108.40.206 COMMITTED GPFS File Manager gpfs.msg.en_US 220.127.116.11 COMMITTED GPFS Server Messages ‑ U.S. gpfs.base 18.104.22.168 COMMITTED GPFS File Manager gpfs.docs.data 22.214.171.124 COMMITTED GPFS Server Manpages and
The latest GPFS updates are installed next. Again, you can use SMIT (or
installp) to update the file sets to the latest level. The
lslpp command can be used to verify that the GPFS file sets have been updated.
aixlpar1 : /tmp/cg/gpfs_fixes_3510 #inutoc . aixlpar1 : /tmp/cg/gpfs_fixes_3510 #ls ‑ltr total 580864 ‑rw‑r‑‑r‑‑ 1 30007 bin 910336 Feb 9 00:10 U858102.gpfs.docs.data.bff ‑rw‑r‑‑r‑‑ 1 30007 bin 47887360 May 8 08:48 U859646.gpfs.base.bff ‑rw‑r‑‑r‑‑ 1 30007 bin 99655680 May 8 08:48 U859647.gpfs.gnr.bff ‑rw‑r‑‑r‑‑ 1 30007 bin 193536 May 8 08:48 U859648.gpfs.msg.en_US.bff ‑rw‑r‑‑r‑‑ 1 root system 4591 May 10 05:15 changelog ‑rw‑r‑‑r‑‑ 1 root system 3640 May 10 05:42 README ‑rw‑r‑‑‑‑‑ 1 root system 55931 May 15 10:23 GPFS‑126.96.36.199‑power‑AIX.readme.html ‑rw‑r‑‑‑‑‑ 1 root system 148664320 May 15 10:28 GPFS‑188.8.131.52‑power‑AIX.tar ‑rw‑r‑‑r‑‑ 1 root system 8946 May 15 14:48 .toc aixlpar1 : /tmp/cg/gpfs_fixes_3510 #smitty update_all COMMAND STATUS Command: OK stdout: yes stderr: no Before command completion, additional instructions may appear below. MORE...59Finished processing all filesets. (Total time: 18 secs). +‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑+ Pre‑commit Verification... +‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑+ Verifying requisites...done Results... SUCCESSES ‑‑‑‑‑‑‑‑‑ Filesets listed in this section passed pre‑commit verification and will be committed. Selected Filesets ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ gpfs.base 184.108.40.206 #GPFS File Manager gpfs.msg.en_US 220.127.116.11 #GPFS Server Messages ‑ U.S. ... << End of Success Section >> +‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑+ Committing Software... +‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑+ installp: COMMITTING software for: gpfs.base 18.104.22.168 Filesets processed: 1 of 2 (Total time: 18 secs). installp: COMMITTING software for: gpfs.msg.en_US 22.214.171.124 Finished processing all filesets. (Total time: 18 secs). +‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑+ Summaries: +‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑+ Installation Summary ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ Name Level Part Event Result ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ gpfs.msg.en_US 126.96.36.199 USR APPLY SUCCESS gpfs.base 188.8.131.52 USR APPLY SUCCESS gpfs.base 184.108.40.206 ROOT APPLY SUCCESS gpfs.base 220.127.116.11 USR COMMIT SUCCESS gpfs.base 18.104.22.168 ROOT COMMIT SUCCESS gpfs.msg.en_US 22.214.171.124 USR COMMIT SUCCESS aixlpar1 : /tmp/cg/gpfs_fixes_3510 #lslpp ‑l gpfs\∗ Fileset Level State Description ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ Path: /usr/lib/objrepos gpfs.base 126.96.36.199 COMMITTED GPFS File Manager gpfs.msg.en_US 188.8.131.52 COMMITTED GPFS Server Messages ‑ U.S. English Path: /etc/objrepos gpfs.base 184.108.40.206 COMMITTED GPFS File Manager Path: /usr/share/lib/objrepos gpfs.docs.data 220.127.116.11 COMMITTED GPFS Server Manpages and Documentation
Repeat the update on the second node.
Configuring the GPFS cluster
Now that GPFS is installed, we can create a cluster across both AIX systems. First, we create a text file that contains a list of each of the nodes and their GPFS description and purpose. We have chosen to configure each node as a GPFS quorum manager. Each node is a GPFS server.
aixlpar1 : /tmp/cg #cat gpfs‑nodes.txt aixlpar2p:quorum‑manager: aixlpar1p:quorum‑manager:
The cluster is created using the
mmcrcluster command. The GPFS cluster name is GPFS_CLUSTER1. The primary node (or NSD server; discussed in the next section) is aixlpar1p and the secondary node is aixlpar2p. We have specified that ssh and *scp will be used for cluster communication and administration.
aixlpar1 : /tmp/cg #mmcrcluster –C GPFS_CLUSTER1 ‑N /tmp/cg/gpfs‑nodes.txt ‑p aixlpar1p ‑s aixlpar2p ‑r /usr/bin/ssh ‑R /usr/bin/scp Mon Apr 29 12:01:21 EET 2013: mmcrcluster: Processing node aixlpar2 Mon Apr 29 12:01:24 EET 2013: mmcrcluster: Processing node aixlpar1 mmcrcluster: Command successfully completed mmcrcluster: Warning: Not all nodes have proper GPFS license designations. Use the mmchlicense command to designate licenses as needed. mmcrcluster: Propagating the cluster configuration data to all affected nodes. This is an asynchronous process.
Note: To ensure that GPFS daemon communication occurs over the private GPFS network, during cluster creation, we specified the GPFS daemon node names (that is, host names ending with p). There are two types of communication to consider in a GPFS cluster, administrative commands and daemon communication. Administrative commands use remote shell (
rsh, or other) and socket-based communications. It is considered as a best practice to ensure that all GPFS daemon__communication is performed over a private network. Refer to the GPFS IBM Developer wiki for further information and discussion on GPFS network configuration considerations and practices.
To use a separate network for administration command communication, you can change the “Admin node name” using the
mmchnode command. In this example, the separate network address is designated by “a” (for Administration) at the end of the node name,
aixlpar1a for example.
#mmchnode ‑admin‑interface=aixlpar1p ‑N aixlpar1a #mmchnode ‑admin‑interface=aixlpar2p ‑N aixlpar2a
mmcrcluster command warned us that not all nodes have the appropriate GPFS license designation. We use the
mmchlicense command to assign a GPFS server license to both the nodes in the cluster.
aixlpar1 : / #mmchlicense server ‑‑accept ‑N aixlpar1a,aixlpar2a The following nodes will be designated as possessing GPFS server licenses: aixlpar2a aixlpar1a mmchlicense: Command successfully completed mmchlicense: Propagating the cluster configuration data to all affected nodes. This is an asynchronous process.
The cluster is now configured. The
mmlscluster command can be used to display cluster information.
#mmlscluster GPFS cluster information ======================== GPFS cluster name: GPFS_CLUSTER1.aixlpar1p GPFS cluster id: 8831612751005471855 GPFS UID domain: GPFS_CLUSTER.aixlpar1p Remote shell command: /usr/bin/ssh Remote file copy command: /usr/bin/scp GPFS cluster configuration servers: ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ Primary server: aixlpar1p Secondary server: aixlpar2p Node Daemon node name IP address Admin node name Designation ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 1 aixlpar2p 10.1.7.120 aixlpar2a quorum‑manager 2 aixlpar1p 10.1.7.110 aixlpar1a quorum‑manager
At this point, you can use the
mmdsh command to verify that the SSH communication is working as expected on all GPFS nodes. This runs a command on all the nodes in the cluster. If there is an SSH configuration problem, this command highlights the issues.
aixlpar1 : / #mmdsh date aixlpar1: Mon Apr 29 12:05:47 EET 2013 aixlpar2: Mon Apr 29 12:05:47 EET 2013 aixlpar2 : / #mmdsh date aixlpar1: Mon Apr 29 12:06:41 EET 2013 aixlpar2: Mon Apr 29 12:06:41 EET 2013
Configuring Network Shared Disks
GPFS provides a block-level interface over TCP/IP networks called the Network Shared Disk (NSD) protocol. Whether using the NSD protocol or a direct attachment to the SAN, the mounted file system looks the same to the users and application (GPFS transparently handles I/O requests).
A shared disk cluster is the most basic environment. In this configuration, the storage is directly attached to all the systems in the cluster. The direct connection means that each shared block device is available concurrently to all of the nodes in the GPFS cluster. Direct access means that the storage is accessible using a Small Computer System Interface (SCSI) or other block-level protocol using a SAN.
The following figure illustrates a GPFS cluster where all nodes are connected to a common Fibre Channel SAN and storage device. The nodes are connected to the storage using the SAN and to each other using a local area network (LAN). Data used by applications running on the GPFS nodes flows over the SAN, and GPFS control information flows among the GPFS instances in the cluster over the LAN. This configuration is optimal when all nodes in the cluster need the highest performance access to the data.
Figure 3. Overview diagram of the GPFS cluster
mmcrnsd command is used to create NSD devices for GPFS. First, we create a text file that contains a list of each of the hdisk names, their GPFS designation (data, metadata, both*), and the NSD name.
hdisk1:::dataAndMetadata::nsd01:: hdisk2:::dataAndMetadata::nsd02:: hdisk3:::dataAndMetadata::nsd03:: hdisk4:::dataAndMetadata::nsd04:: hdisk5:::dataAndMetadata::nsd05:: hdisk6:::dataAndMetadata::nsd06::
Then, run the
mmcrnsd command to create the NSD devices.
#mmcrnsd ‑F /tmp/cg/gpfs‑disks.txt mmcrnsd: Processing disk hdisk1 mmcrnsd: Processing disk hdisk2 mmcrnsd: Processing disk hdisk3 mmcrnsd: Processing disk hdisk4 mmcrnsd: Processing disk hdisk5 mmcrnsd: Processing disk hdisk6 mmcrnsd: Propagating the cluster configuration data to all affected nodes. This is an asynchronous process.
lspv command now shows the NSD name associated with each AIX hdisk.
#lspv hdisk0 00c334b6af00e77b rootvg active hdisk1 none nsd01 hdisk2 none nsd02 hdisk3 none nsd03 hdisk4 none nsd04 hdisk5 none nsd05 hdisk6 none nsd06
mmlsnsd command displays information for each NSD, in particular which GPFS file system is associated with each device. At this point, we have not created a GPFS file system. So each disk is currently free. You’ll notice that under NSD servers each device is shown as directly attached. This is expected for SAN-attached disks.
#mmlsnsd File system Disk name NSD servers ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ (free disk) nsd01 (directly attached) (free disk) nsd02 (directly attached) (free disk) nsd03 (directly attached) (free disk) nsd04 (directly attached) (free disk) nsd05 (directly attached) (free disk) nsd06 (directly attached)
GPFS file system configuration
Next, the GPFS file systems can be configured. The
mmcrfs command is used to create the file systems. We have chosen to create two file systems; /gpfs and /gpfs1. The /gpfs (gpfs0) file system will be configured with a GPFS block size of 256K (the default) and /gpfs1 (gpfs1) with a block size of 1M*. Both file systems are configured for replication (-M2 –R2). The /tmp/cg/gpfs-disk.txt file is specified for /gpfs and /tmp/cg/gpfs1-disk.txt for /gpfs1. These files specify which NSD devices are used for each file system during creation.
Note: Choose your block size carefully. It is not possible to change this value after the GPFS device has been created.
#cat /tmp/cg/gpfs‑disk.txt nsd01:::dataAndMetadata:‑1::system nsd02:::dataAndMetadata:‑1::system nsd03:::dataAndMetadata:‑1::system #cat /tmp/cg/gpfs1‑disk.txt nsd04:::dataAndMetadata:‑1::system nsd05:::dataAndMetadata:‑1::system nsd06:::dataAndMetadata:‑1::system #mmcrfs /gpfs gpfs0 ‑F/tmp/cg/gpfs‑disks.txt ‑M2 ‑R 2 #mmcrfs /gpfs1 gpfs1 ‑F/tmp/cg/gpfs1‑disks.txt ‑M2 ‑R 2 –B 1M
mmlsnsd command displays the NSD configuration per file system. NSD devices 1 to 3 are assigned to the gpfs0 device and devices 4 to 6 are assigned to gpfs1.
#mmlsnsd File system Disk name NSD servers ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ gpfs0 nsd01 (directly attached) gpfs0 nsd02 (directly attached) gpfs0 nsd03 (directly attached) gpfs1 nsd04 (directly attached) gpfs1 nsd05 (directly attached) gpfs1 nsd06 (directly attached)
Both GPFS file systems are now available on both nodes.
aixlpar1 : / #df ‑g Filesystem GB blocks Free %Used Iused %Iused Mounted on /dev/hd4 1.00 0.89 12% 5211 3% / /dev/hd2 3.31 0.96 71% 53415 18% /usr /dev/hd9var 2.00 1.70 16% 5831 2% /var /dev/hd3 2.00 1.36 33% 177 1% /tmp /dev/hd1 2.00 2.00 1% 219 1% /home /proc ‑ ‑ ‑ ‑ ‑ /proc /dev/hd10opt 1.00 0.79 21% 3693 2% /opt /dev/local 1.00 0.97 3% 333 1% /usr/local /dev/loglv 1.00 1.00 1% 54 1% /var/log /dev/tsmlog 1.00 1.00 1% 7 1% /var/tsm/log /dev/hd11admin 0.12 0.12 1% 13 1% /admin /dev/optIBMlv 2.00 1.99 1% 17 1% /opt/IBM /dev/gpfs1 150.00 147.69 2% 4041 3% /gpfs1 /dev/gpfs0 150.00 147.81 2% 4041 7% /gpfs
mmdsh command can be used here to quickly check the file system status on all the nodes.
aixlpar1 : / #mmdsh df ‑g | grep gpfs aixlpar2: /dev/gpfs0 150.00 147.81 2% 4041 7% /gpfs aixlpar2: /dev/gpfs1 150.00 147.69 2% 4041 3% /gpfs1 aixlpar1: /dev/gpfs1 150.00 147.69 2% 4041 3% /gpfs1 aixlpar1: /dev/gpfs0 150.00 147.81 2% 4041 7% /gpfs
If more detailed information is required, the
mmdf command can be used.
aixlpar1 : /gpfs #mmdf gpfs0 ‑‑block‑size=auto disk disk size failure holds holds free free name group metadata data in full blocks in fragments ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑ ‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑ Disks in storage pool: system (Maximum disk size allowed is 422 GB) nsd01 50G ‑1 yes yes 49.27G ( 99%) 872K ( 0%) nsd02 50G ‑1 yes yes 49.27G ( 99%) 936K ( 0%) nsd03 50G ‑1 yes yes 49.27G ( 99%) 696K ( 0%) ‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ (pool total) 150G 147.8G ( 99%) 2.445M ( 0%) ============= ==================== =================== (total) 150G 147.8G ( 99%) 2.445M ( 0%) Inode Information ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ Number of used inodes: 4040 Number of free inodes: 62008 Number of allocated inodes: 66048 Maximum number of inodes: 66048 aixlpar1 : /gpfs #mmdf gpfs1 ‑‑block‑size=auto disk disk size failure holds holds free free name group metadata data in full blocks in fragments ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑ ‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ Disks in storage pool: system (Maximum disk size allowed is 784 GB) nsd04 50G ‑1 yes yes 49.55G ( 99%) 1.938M ( 00%) nsd05 50G ‑1 yes yes 49.56G ( 99%) 992K ( 0%) nsd06 50G ‑1 yes yes 49.56G ( 99%) 1.906M ( 00%) ‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ (pool total) 150G 148.7G ( 99%) 4.812M ( 00%) ============= ==================== =================== (total) 150G 148.7G ( 99%) 4.812M ( 00%) Inode Information ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ Number of used inodes: 4040 Number of free inodes: 155704 Number of allocated inodes: 159744 Maximum number of inodes: 159744
Node quorum with tiebreaker disks
Tiebreaker disks are recommended when you have a two-node cluster or you have a cluster where all of the nodes are SAN-attached to a common set of logical unit numbers (LUNs) and you want to continue to serve data with a single surviving node. Typically, tiebreaker disks are only used in two-node clusters. Tiebreaker disks are not special NSDs; you can use any NSD as a tiebreaker disk.
In this example, we chose three (out of six) NSD devices as tiebreaker disks. We stopped GPFS on all nodes and configured the cluster accordingly.
#mmshutdown ‑a #mmchconfig tiebreakerDisks="nsd01;nsd03;nsd05" #mmstartup ‑a
Cluster daemon status
There are two GPFS daemons (processes) that remain active while GPFS is active (
#ps ‑ef | grep mmfs root 4784176 5505220 0 May 20 ‑ 0:27 /usr/lpp/mmfs/bin/aix64/mmfsd64 root 5505220 1 0 May 20 ‑ 0:00 /usr/lpp/mmfs/bin/mmksh /usr/lpp/mmfs/bin/runmmfs
You can use the
mmgetstate command to view the status of the GPFS daemons on all the nodes in the cluster.
#mmgetstate ‑aLs Node number Node name Quorum Nodes up Total nodes GPFS state Remarks ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 1 aixlpar2a 1∗ 2 2 active quorum node 2 aixlpar1a 1∗ 2 2 active quorum node Summary information ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ Number of nodes defined in the cluster: 2 Number of local nodes active in the cluster: 2 Number of remote nodes joined in this cluster: 0 Number of quorum nodes defined in the cluster: 2 Number of quorum nodes active in the cluster: 2 Quorum = 1∗, Quorum achieved
Congratulations! You’ve just configured your first GPFS cluster. In this article, you’ve learnt how to build a simple two-node GPFS cluster on AIX. This type of configuration can be easily deployed to support clustered workload with high availability requirements, for example an MQ multi-instance cluster. GPFS offers many configuration options; you can spend a lot of time planning for a GPFS cluster. If you are seriously considering a GPFS deployment, I encourage you to read all of the available GPFS documentation in the Resources section on the right.