Quantum 6-01376-05 manual JournalSize, Snfs Tools

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StorNext File System Tuning

The Metadata Controller System

severely consumes metadata space in cases where the file-to-directory ratio is less than 100 to 1. However, startup and failover time can be minimized by increasing FsBlockSize. This is very important for multi- terabyte file systems, and especially when the metadata servers have slow CPU clock speed (such as Sparc and Mips). A good rule of thumb is to use 16K unless other requirements such as directory ratio dictate otherwise. Note that 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

 

man cvfs_config page.) The snfsdefrag man page explains the command

 

options in greater detail.

 

FSM hourly statistics reporting is another very useful tool. This can show

 

you the mix of metadata operations being invoked by client processes, as

 

well as latency information for metadata operations and metadata and

 

journal I/O. This information is easily accessed in the cvlog log files. All

 

of the latency oriented stats are reported in microsecond units.

StorNext File System Tuning Guide

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Contents 01376-05 Copyright Statement Contents Underlying Storage System StorNext File System TuningRAID Cache Configuration RAID Write-Back Caching 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 Settings Affinities 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 MountCommandOptions StorNext File System Tuning Metadata Controller System Hardware Configuration Distributed LAN Disk Proxy NetworksSnfs External API StorNext File System Tuning Guide Network Configuration and Topology SAN Windows Memory Requirements Distributed LAN ServersStorNext File System Tuning Windows Memory Requirements StorNext 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
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