HP StoreAll Storage - Manual (Page 110)

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.
Expanding a file system
You can make tier assignments for new segments as you add them.
NOTE: Verify that no tiering job is running before executing the file system expansion commands.
The expansion takes priority and the tiering job is terminated.
To including tiering at the time you expand a file system, use the following command:
<installdirectory>/bin/ibrix_fs -e -f FSNAME -s LVLIST -t TIERNAME
This command extends the file system FSNAME with the segments in LVLIST and assigns the
segments to TIERNAME. If tiering policy rules are already defined for this file system, the -t option
is required.
To extend file system FSNAME with the listed tiered segment/owner pairs:
<installdirectory>/bin/ibrix_fs -e -f FSNAME -S LV1:HOSTNAME1,LV2:HOSTNAME2,...
-t TIERNAME
To extend file system FSNAME with the physical volumes in PVLIST:
<installdirectory>/bin/ibrix_fs -e -f FSNAME -p PVLIST -t TIERNAME
Allocation policy
The allocation policy manager is responsible for determining the initial placement of files when
they are created. The allocation policy command can use all of the segments currently in the tier.
To specify that all segments within a named tier be used for initial placement of new files, use the
ibrix_fs_tune
command to explicitly prefer the tier.
<installdirectory>/bin/ibrix_fs_tune -f FSNAME {-h HOSTLIST|-g GROUPLIST} -t TIERNAME
This command designates a primary tier and prefers the pool of segments identified by the tier
name (TIERNAME) on a list of specified hosts (HOSTLIST) or hostgroups (GROUPLIST). You can
prefer only one primary tier in a file system.
Unpreferred segments in other secondary tiers are ignored by the allocation policy manager and
only used by ibrix_migrator when moving files according to the tiering policy. For example,
in a file system with six segments, you might specify the following configuration:
1. Add the first three segments to tier T1.
<installdirectory>/bin/ibrix_tier -a -f ifs1 -t T1 -S 1,2,3
2. Execute ibrix_fs_tune to prefer tier T1, which contains segments s1-s3 for initial file
writes.
<installdirectory>/bin/ibrix_fs_tune -f ifs1 -h ss2 -t T1
3. Assign segments s4-s6 to a second tier.
<installdirectory>/bin/ibrix_tier -a -f ifs1 -t T2 -S 4,5,6
The tiering policy can now be used to move matching files from tier T1, where they will be stored
on creation, to tier T2 based on file attribute conditions.
If you add segments to the primary tier at a later time, the segments automatically become preferred.
Similarly, the data tiering feature unprefers any segment removed from the primary tier at a later
time.
110 Using data tiering