Issues caused by the use of configurations or commands related to maintenance and operation
This section discusses the issues caused due to the unhealthy state of the components used in the IBM Spectrum Scale stack
- Suboptimal performance due to maintenance commands in progress
When in progress, long-running GPFS maintenance operations like mmrestripefs, mmapplypolicy, mmadddisk, and mmdeldisk, consume some percentage of the system resources. Significant consumption of the system resources can impact the I/O performance of the application. - Suboptimal performance due to frequent invocation or execution of maintenance commands
When the GPFS maintenance operations like mmbackup, mmapplypolicy, mmdf, mmcrsnapshot, mmdelsnapshot, and others are in progress, they can consume some percentage of system resources. This can impact the I/O performance of applications. If these maintenance operations are scheduled frequently, for example within every few seconds or minutes, the performance impact can be significant, unless the I/O subsystem is sized adequately to handle both the application and the maintenance operation I/O load. - Suboptimal performance when a tracing is active on a cluster
Tracing is usually enabled on the IBM Spectrum Scale cluster for troubleshooting purposes. However, running a trace on a node might cause performance degradation. - Suboptimal performance due to replication settings being set to 2 or 3
The file system write performance depends on the write performance of the storage volumes and its RAID configuration. However, in case the backend storage write performance is on par with its read performance, but the file system write performance is just 50% (half) or 33% (one-third) of the read performance, check if the file system replication is enabled. - Suboptimal performance due to updates made on a file system or fileset with snapshot
If a file is modified after its snapshot creation, the system can face performance degradation due to the copy-on-write property enforced on updated data files.
Parent topic: Performance issues