6.0 HP X9000 File Serving Software File System User Guide (TA768-96043, October 2011)

Note the following:
• A tiering policy can contain multiple rules.
• Tiering rules are based on individual file attributes.
• All rules are executed when the tiering policy is applied during execution of the
ibrix_migrator command.
• It is important that different rules do not target the same files, especially if different destination
tiers are specified. If tiering rules are ambiguous, the final destination for a file is not
predictable. See “Ambiguous rules” (page 153), for more information.
The following are examples of attributes that can be specified in rules. All attributes are listed in
“Rule keywords” (page 152). You can use AND and OR operators to create combinations.
Access time
• File was last accessed x or more days ago
• File was accessed in the last y days
Modification time
• File was last modified x or more days ago
File size—greater than n K
File name or File type—jpg, wav, exe (include or exclude)
File ownership—owned by user(s) (include or exclude)
Use of the tiering assignments or policy on any file system is optional. Tiering is not assigned by
default; there is no “default” tier.
Tiered file systems
You can create a tiered file system at any time. You can assign tier names to file serving nodes
when creating a file system or assign tiers after the file system is in place.
• Use the ibrix_fs -t TIERNAME option to create or expand a file system with tiered
segments.
• Use ibrix_tier to assign segments to tiers, change a segment’s tier assignment, and delete
a tier.
• Use ibrix_migrator to start and stop tiering operations, and to write and manage the
rules that govern tiering policy.
You can configure and manage data tiering from the management console GUI or from the CLI
using the ibrix_tier and ibrix_migrator commands. This section provides instructions for
using the CLI commands. For more information about these commands, see the HP X9000 File
Serving Software CLI Reference Guide.
Creating a file system that uses data tiering
The ibrix_fs command, which is used to create or expand a file system, includes a -t
TIERNAME option that can be used to create a data tier. Use the following command to create
the file system:
ibrix_fs -c -f FSNAME -s LVLIST -t TIERNAME ....
The command creates file system FSNAME with the segments in LVLIST assigned to TIERNAME.
TIERNAME can be any alphanumeric, case-sensitive, text string. Tier assignment is not affected by
other options that can be set with the ibrix_fs command.
NOTE: A tier is created whenever a segment is assigned to it. Be careful to spell the name of the
tier correctly when you add segments to an existing tier. If you make an error in the name, a new
tier is created with the incorrect tier name, and no error is recognized.
148 Using data tiering