Quantum 6-01376-07 manual JournalSize, Snfs Tools

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StorNext File System Tuning

The Metadata Controller System

Settings greater than 64K are not recommended because performance will be adversely impacted due to inefficient metadata I/O operations. Values less than 16K are not recommended in most scenarios because startup and failover time may be adversely impacted. Setting FsBlockSize to higher values is important for multiterabyte file systems for optimal startup and failover time.

Note: This is particularly true for slow CPU clock speed metadata servers such as Sparc. However, values greater than 16K can severely consume metadata space in cases where the file-to- directory ratio is low (e.g. less than 100 to 1).

The best rule of thumb is to use 16K unless other requirements such as directory ratio dictate otherwise.

This setting is not adjustable after initial file system creation, so it is very important to give it careful consideration during initial configuration.

Example: FsBlockSize

16K

JournalSize

 

The optimal settings are in the range between 16M and 64M. Avoid

values greater than 64M due to potentially severe impacts on startup and

failover times. Values at the higher end of the 16M-64M range may

improve performance of metadata operations in some cases, although at

the cost of slower startup and failover time. A good rule of thumb is to

use 16M unless another requirement dictates differently. This setting is

adjustable using the cvupdatefs utility. For more information, see the

cvupdatefs man page.

 

Example: JournalSize

16M

 

The snfsdefrag tool is very useful to identify and correct file extent

SNFS Tools

fragmentation. Reducing extent fragmentation can be very beneficial for

 

 

performance. You can use this utility to determine whether files are

 

fragmented, and if so, fix them. If your files are prone to fragmentation

 

you should also use the FSM config file tuning options to minimize

 

fragmentation. These global configuration settings are InodeExpandMin,

 

InodeExpandInc, and InodeExpandMax. (For more information, see the

StorNext File System Tuning Guide

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Contents
ExtNrotS Copyright Statement Contents Underlying Storage System StorNext File System TuningRAID Cache Configuration RAIDWrite-BackCaching RAID Read-Ahead Caching RAID Level, Segment Size, and Stripe Size File Size Mix and Application I/O Characteristics Direct Memory Access DMA I/O TransferBuffer Cache NFS / Cifs Metadata Controller System Metadata NetworkStripe Groups FSM Configuration File SettingsAffinities ExampleBufferCacheSize StripeBreadthFsBlockSize InodeCacheSizeThreadPoolSize ForcestripeAlignmentSnfs Tools JournalSizeStorNext File System Tuning Metadata Controller System StorNext File System Tuning Metadata Controller System StorNext File System Tuning Metadata Controller System Latency-testindex-number seconds Mount Command Options Hardware Configuration Distributed LAN Disk Proxy NetworksSnfs External API Network Configuration and Topology Multi-NIC Hardware and IP Configuration Diagram Distributed LAN Client Vs. Legacy Network Attached Storage Distributed LAN ServersLargest Tested Configuration Number of Clients Tested viaSimulation Consistent Windows Memory RequirementsStorNext File System Tuning Windows Memory Requirements Sample FSM Configuration File MAXStripeBreadth StorNext File System Tuning Sample FSM Configuration File StorNext File System Tuning Sample FSM Configuration File StorNext File System Tuning Sample FSM Configuration File