User's Manual

StorNext File System Tuning
The Metadata Controller System
StorNext File System Tuning Guide 13
Example: ThreadPoolSize 32 # default 16, 512 KB memory per
thread
ForcestripeAlignment
This setting should always be set to Yes. This is critical if the largest
StripeBreadth defined is greater than 1MB. Note that this setting is not
adjustable after initial file system creation.
Example: ForcestripeAlignment Yes
FsBlockSize
The FsBlockSize (FSB), metadata disk size, and JournalSize settings all
work together. For example, the FsBlockSize must be set correctly in
order for the metadata sizing to be correct. JournalSize is also
dependent on the FsBlockSize.
For FsBlockSize the optimal settings for both performance and space
utilization are in the range of 16K or 64K.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).
For metadata disk size, you must have a minimum of 25 GB, with more
space allocated depending on the number of files per directory and the
size of your file system.
The following table shows suggested FsBlockSize (FSB) settings and
metadata disk space based on the average number of files per directory
and file system size. The amount of disk space listed for metadata is
in
addition
to the 25 GB minimum amount. Use this table to determine the
setting for your configuration.