6.5 HP StoreAll OS User Guide

A StoreAll client or StoreAll file serving node (referred to as “the host”) uses the following precedence
rules to evaluate the file allocation settings that are in effect:
• The host uses the default allocation policies and segment preferences: The RANDOM policy
is applied, and a segment is chosen from among ALL the available segments.
• The host uses a non-default allocation policy (such as ROUNDROBIN) and the default segment
preference: Only the file or directory allocation policy is applied, and a segment is chosen
from among ALL available segments.
• The host uses a non-default segment preference and a non-default allocation policy (such as
LOCAL/ROUNDROBIN): A segment is chosen according to the following rules:
◦ From the pool of preferred segments, select a segment according to the allocation policy
set for the host, and store the file in that segment if there is room. If all segments in the
pool are full, proceed to the next rule.
◦ Use the AUTOMATIC allocation policy to choose a segment with enough storage room
from among the available segments, and store the file.
When file allocation settings take effect on the StoreAll client
Although file allocation settings are executed immediately on file serving nodes, for the StoreAll
client, a file allocation intention is stored in the Fusion Manager. When StoreAll software services
start on a client, the client queries the Fusion Manager for the file allocation settings that it should
use and then implements them. If the services are already running on a client, you can force the
client to query the Fusion Manager by executing ibrix_client or ibrix_lwhost --a on the
client, or by rebooting the client.
Using CLI commands for file allocation
Follow these guidelines when using CLI commands to perform any file allocation configuration
tasks:
• To perform a task for NAS clients (NFS, CIFS, FTP, HTTP), specify file serving nodes for the
-h HOSTLIST argument.
• To perform a task for StoreAll clients, specify individual clients for -h HOSTLIST or specify
a hostgroup for -g GROUPLIST. Hostgroups are a convenient way to configure file allocation
settings for a set of StoreAll clients. To configure file allocation settings for all StoreAll clients,
specify the clients hostgroup.
Setting file and directory allocation policies
You can set a nondefault file or directory allocation policy for file serving nodes and StoreAll
clients. You can also specify the first segment where the policy should be applied, but in practice
this is useful only for the ROUNDROBIN policy.
IMPORTANT: Certain allocation policies are deprecated. See “File allocation policies” (page 391)
for a list of standard allocation policies.
On the Management Console, open the Modify Filesystem Properties dialog box and select the
Host Allocation tab.
Setting file and directory allocation policies 393