HP StoreAll Storage - Manual (Page 241)

Standard segment preferences and allocation policies
Comment Description Name
This is the default segment preference. It is suitable
for most use cases. Prefer all of the segments available in the file
system for new files and directories. ALL
No writes are routed between the file serving nodes
in the cluster. This preference is beneficial for Prefer the file serving node’s local segments for
new files and directories. LOCAL
performance in some configurations and for some
workloads, but can cause some segments to be
overutilized.
This is the default allocation policy. It generally
spreads new files and directories evenly (by number Allocate files to a randomly chosen segment
among preferred segments. RANDOM
of files, not by capacity) across all of the preferred
segments; however, that is not guaranteed.
This policy guarantees that new files and folders
are spread evenly across the preferred segments
(by number of files, not by capacity). Allocate files to preferred segments in segment
order, returning to the first segment (or the
designated starting segment) when a file or
directory has been allocated to the last segment. ROUNDROBIN
Deprecated segment preferences and allocation policies
IMPORTANT: HP recommends that you do not use these options. They are currently supported
but will be removed in a future release.
Comment Description Name
Should be used only on the advice
of HP support. Lets the IBRIX software select the allocation policy. AUTOMATIC
Should be used only on the advice
of HP support. Allocates files to the segment where its parent
directory is located. DIRECTORY
Should be used only on the advice
of HP support. Allocates files to one segment until the segment’s
storage limit is reached, and then moves to the next STICKY
segment as determined by the AUTOMATIC file
allocation policy.
Should be used only on the advice
of HP support. For clusters with more than 16 file serving nodes,
takes a subset of the servers to be used for file HOST_ROUNDROBIN_NB
creation and rotates this subset on a regular, periodic
basis.
Use NONE only to set file and
directory allocation to the same
policy. Sets directory allocation policy only. Causes the
directory allocation policy to revert to its default,
which is the policy set for file allocation. NONE
How file allocation settings are evaluated
By default, ALL segments are preferred and file systems use the RANDOM allocation policy. These
defaults are adequate for most IBRIX environments; but in some cases, it may be necessary to
change the defaults to optimize file storage for your system.
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