HP StorageWorks Scalable File Share - Manual (Page 116)

Creating and modifying file systems 5–32
5. Select the service and then select the preferred server for the service.
Repeat this step for each service where you want to change the preferred server. When you have
made your changes, press the
Return
key without selecting a service.
6. Restart the file system, as shown in the following example:
sfs> start filesystem data
7. When the file system restarts, the client nodes can remount the file system. If a client node fails to
remount the file system, reboot the client node.
5.6.3 Modifying service mount options
Underlying the OST and MDS services on the Lustre file systems, there are
ldiskfs
file systems. When an
OST or MDS service starts, it mounts the underlying
ldiskfs
file system so that it can access the data. You
can specify mount options on these file systems to determine what happens when the file systems are
mounted.
In HP SFS Version 2.2, the
extents
and the
mballoc
mount options are supported for OST services:
• Enabling the
extents
option on file systems underlying OST services improves file system
performance; for this reason, the default when creating a file system is to enable this option on OST
services. Do not set this mount option on MDS services.
• The setting for the
mballoc
option is determined by the file I/O pattern specified for the file system.
Do not change the setting for the
mballoc
option on an existing file system.
The
acl
and
user_xattrs
options may be set for MDS services:
• The
acl
option must be enabled if Access Control Lists (ACLs) are to be used when the file system is
mounted on client nodes.
• The u
ser_xattrs
option must be enabled if extended attributes are to be used when the file system
is mounted.
HP recommends that you enable the ACL functionality on your HP SFS file systems, unless your system is
running in Portals compatibility mode.
CAUTION: If your system is running in Portals compatibility mode, do not enable the
acl
option or the
user_xattrs
option on a file system. Client nodes will not be able to successfully mount a file system that
has these options enabled while the system is running in Portals compatibility mode.
Changing mount options can have irreversible effects on file systems. HP recommends that you do not
experiment with changing mount options unless specifically requested to do so by your HP Customer Support
representative.
To specify mount options, perform the following steps:
1. Unmount the file system on all client nodes.
2. Stop the file system as shown in the following example, where the
data
file is system is stopped:
sfs> stop filesystem data
Do not proceed to the next step (running the
modify filesystem
command) until the file system is
stopped; the file system is stopped when all of the file system services are in the
stopped
or
down
state. See Section 3.7 for more information on the
stop filesystem
command.