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gpfs:gpfs_sizing

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Spectrum Scale sizing

VM sizing for IBM Storage Scale

Sizing Summary for a Small Cluster

A common starting point for a small, moderately performing virtual Storage Scale cluster might be:

  • Minimum Nodes: 3 (for quorum and basic replication)
  • Per NSD Server VM:
  vCPU: 8 vCPUs
  vRAM: 16 GB
  Network: 2 x 25 Gbps vNICs (bonded for I/O)
  • Per Protocol node:
  vCPU: 1 vCPUs
  vRAM: 64 GB or 128 GB if NFS ans SMB is used
  Network: 10 Gbps 
  • Storage: Virtual disks backed by high-speed SAN LUNs (or local disks on the hypervisor host if using FPO).
  • Best Practice: Use physical mode Raw Device Mapping (RDM) or the virtualization platform's equivalent for best I/O performance and direct control over the LUNs from the Storage Scale VMs.

https://community.ibm.com/community/user/blogs/ramesh-krishnamaneni/2025/09/26/optimizing-ibm-storage-scale-in-ibm-cloud-vsi-vs-b

Features in IBM Storage Scale editions

Feature Data Access Data Management1 Erasure Code Edition
Multi-protocol scalable file service with simultaneous access to a common set of data
Facilitate data access with a global namespace, massively scalable file system, quotas and snapshots, data integrity and availability, and filesets
Simplify management with GUI
Improved efficiency with QoS and compression
Create optimized tiered storage pools based on performance, locality, or cost
Simplify data management with Information Lifecycle Management (ILM) tools that include policy based data placement and migration
Enable worldwide data access using AFM asynchronous replication
Asynchronous multi-site Disaster Recovery
Multi-site replication with AFM to cloud object storage
Protect data with native software encryption and secure erase, NIST compliant and FIPS certified
File audit logging
Watch folder
Erasure coding ESS only ESS only

Filesystem Block size, best practice

Typically, metadata is between 1 and 5% of the filesystem space, but this can vary.

Depending on usage, you can have different block size

IO TypeApplication ExamplesBlocksize
Large Sequential IOScientific Computing, Digital Media,File based Analytics1MB to 16MB
Relational DatabaseDB2, Oracle, Small Files on ESS512KiB
Small I/O SequentialGeneral File Service ,Email, Web Applications256KiB
Special*Special16KB-64KiB
*Since GPFS 3.3 there are very few workloads that benefit from a file system blocksize of 16KiB or 64KiB.
WorkloadConfiguration TypeBlocksize
SAP HANAESS GL16MiB for Data
SAP HANAFPO1MiB for single pool
Or
256KiB for metadataOnly
2MiB for dataOnly
HadoopESS GL1MiB for metadataOnly
8MiB for dataOnly
Hadoop FPO256KiB for metadataOnly
2MiB for dataonly
Spark FPO256KiB for metadataOnly
2MiB for dataOnly
SAP Sybase IQ ESS GL256KiB-1MiB for metadataOnly
16MiB for dataOnly
Healthcare (Medical Imaging)ESS256KiB for metadataOnly
1MiB for dataOnly
Healthcare (Medical Imaging)Other Storage256KiB Metadata and data
ArchiveOther StorageDepends on storage and performance requirements
ECMOther Storage256KiB Unless the content is very large files (Videos for example).
Oracle Other Storage 256KiB
Technical ComputingESS GL1MIB Metadata
4MiB - 16MiB Data depending on importance of peak sequential performance.
SASESS1MiB MetadataOnly
8MiB or 16MiB depending on the SASBUF size (128KiB or 256 KiB)
Enterprise File (Misc Projects, data sharing) Other Storage256KiB metadata and data

Customization

NSD access

During NSD creation alternate node position for access to NSD. If the first node is used as first node in NSD definition, then it 'll be only use and you'll reach performance problems

If only the first node is selected as first into NSD definition means every NSD task ( read/ write … ) has to be handled by NSD server 'gpfs1' as long as he is reachable. Such a configuration could cause a overload situation on the affected server.

The NSD server sequence can be adjusted online via command mmchnsd ( see below ): https://www.ibm.com/docs/en/spectrum-scale/5.0.5?topic=disks-changing-your-nsd-configuration Ex:

# mmchnsd "data_nsd043:gpfs03.gpfsint.labo,gpfs04.gpfsint.labo,gpfs01.gpfsint.labo,gpfs02.gpfsint.labo"

Maybe easier with a description file

# mmlsnsd -X
File system Disk name NSD volume ID NSD servers
------------------------------------------------------------------------------------------------
cases data_nsd043 C0A80017543D01BC gpfs03.gpfsint.labo,gpfs04.gpfsint.labo,gpfs01.gpfsint.labo,gpfs02.gpfsint.labo
cases data_nsd044 C0A80018543CE5A2 gpfs04.gpfsint.labo,gpfs01.gpfsint.labo,gpfs02.gpfsint.labo,gpfs03.gpfsint.labo
cases data_nsd045 C0A80017543D01C3 gpfs01.gpfsint.labo,gpfs02.gpfsint.labo,gpfs03.gpfsint.labo,gpfs04.gpfsint.labo
cases data_nsd046 C0A80018543CE5A8 gpfs02.gpfsint.labo,gpfs03.gpfsint.labo,gpfs04.gpfsint.labo,gpfs01.gpfsint.labo
cases data_nsd047 C0A80017543D01C9 gpfs03.gpfsint.labo,gpfs04.gpfsint.labo,gpfs01.gpfsint.labo,gpfs02.gpfsint.labo
gpfs/gpfs_sizing.1763373840.txt.gz · Last modified: 2025/11/17 11:04 by manu