The GPFS Cluster filesystem extension (AIX & Linux)

The GPFS (General Parallel File System) filesystem extension is the core component that integrates IBM Spectrum Scale with the operating system’s Virtual File System (VFS) layer, allowing GPFS to function as a native filesystem similar to ext3 or xfs.

The GPFS kernel extension registers support at the OS vnode and VFS levels, enabling seamless recognition and handling of GPFS operations. It works closely with GPFS daemons that manage cluster-wide I/O operations, including read-ahead and write-behind optimizations for high-performance data access.

GPFS Filesystem Extension Steps for AIX:

1. Scan the LUNs all the GPFS nodes

# cfgmgr -v

2. Set reserve_policy on each disk on each node

# chdev -l <hdisk#> -a reserve_policy=no_reserve

3. Create the file /tmp/nsdhdiskX.txt

# vi /tmp/nsdhdiskX.txt

%nsd:

         device=/dev/<hdiskX>

         servers=server1,server2,server3,server4

         nsd=<nsd_name>

         usage=dataAndMetadata

         failureGroup=1

         pool=system

4. Create NSD from the file /tmp/nsdhdiskX.txt

# mmcrnsd -F /tmp/nsdhdiskX.txt

5. To see that NSD names corresponding to the disks in lspv output.

# lspv

6. To verify using the mmlsnsd command.

# mmlsnsd

7 Add disk to an existing filesystem

# mmadddisk <gpfs_filesystem> "<nsd_disk name1>;<nsd_disk name2>"

Example:

# mmadddisk gpfs01 nsd1;nsd2

8.To validate the NFS disk attached to the filesystem gpfs filesystem.

# mmlsdisk <gpfs_filesystem>

Example:

# mmlsdisk gpfs01

9. To Check new filesystem size.

# df -g | grep <filesystem_name>

GPFS Filesystem Extension Steps for Linux:

1. Scan the LUNs & find the shared LUNs all the GPFS nodes

# for host in /sys/class/scsi_host/host*; do

echo "- - -" > "$host/scan"

done

#lsblk

2. Create the file /tmp/disk1.txt

# vi /tmp/disk1.txt

%nsd:

       device=</dev/sdX>

       servers=server1,server2,server3,server4

       nsd=<nsd_name>

       usage=dataAndMetadata

       failureGroup=1

       pool=system

3. Create NSD from the file /tmp/disk1.txt

# mmcrnsd -F /tmp/disk1.txt

4. To see that NSD names corresponding to the disks in lspv output.

# lsblk

5. To verify using the mmlsnsd command.

# mmlsnsd

6 Add disk to an existing filesystem

# mmadddisk <gpfs_filesystem> "<nsd_disk name1>;<nsd_disk name2>"

Example:

# mmadddisk gpfs01 nsd1;nsd2

7.To validate the NFS disk attached to the filesystem gpfs filesystem.

# mmlsdisk <gpfs_filesystem>

Example:

# mmlsdisk gpfs01

8. To Check new filesystem size.

# df -h  or df -h <filesystem_name>