HP StorageWorks Scalable File Share - Manual (Page 92)

Creating and modifying file systems 5–8
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.
Stripe count
The stripe count specifies the number of OST services that files are striped over. The suggested stripe count
is one.
NOTE: In earlier versions of the HP SFS software, a stripe count of 0 (zero) resulted in files being striped
over all OST services in the file system. Since HP SFS Version 2.1, this is no longer the case; a stripe count
of 0 now results in files being striped over a single OST service.
The stripe count cannot be larger than the number of OST services assigned to the file system. HP
recommends a stripe count of one for most applications; this stripe count has been shown to provide
maximum aggregate file system bandwidth (see Appendix B for performance figures).
Note that you can apply different custom default stripes to directory trees in the file system after file system
creation (refer to the HP StorageWorks Scalable File Share Client Installation and User Guide for more
information). You can also use the
modify filesystem
command to add OST services to an existing file
system (see Section 5.6).
Interconnects
You will be asked to specify the interconnects that can be used for file system I/O operations. The accessible
interconnects will be listed and you can choose to use some or all of them.
Quota options
Quotas on file systems allow you to specify limits on two aspects of disk storage:
• The number of inodes a user or a group of users may possess.
• The number of disk blocks that may be allocated to a user or a group of users.
Quotas ensure that users do not consume more than their allocated disk consumption limit. Quotas are
handled on a per-user/group, per-filesystem basis. If a user is expected to create files in more than one file
system, quotas must be set for each of the file systems.
The system-wide
quota
attribute must be enabled in order for any file system to use quotas; this attribute is
enabled by default.
On a file system, you can enable quotas for users, groups, or both, by setting the
quotaon
option. In
HP SFS Version 2.2, the
quotaon
option on a file system is set to
ug
(that is, quotas are enabled for both
users and groups) by default when the file system is created, unless the system is running in Portals
compatibility mode.
NOTE: If the HP SFS software on your servers has been upgraded to Version 2.2, but the HP SFS software
on the client nodes has not yet been upgraded, your system will be running in Portals compatibility mode.
Do not enable quotas on file systems while the system is running in Portals compatibility mode. You can use
the
modify filesystem
command to enable quotas on the file system later, when the client nodes have
been upgraded (see Section 5.6 for more information).