HP StorageWorks Scalable File Share - Manual (Page 103)

Creating a file System — SFS20 storage 5–19
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).
When quotas are enabled on a file system, the
itune
and
btune
settings (specified as a percentage) are
used in conjunction with the
iunit
and
bunit
settings to calculate the quantities of inodes and blocks that
will be reserved and released for a user or group.
If you decide to enable quotas on the file system, HP strongly recommends that you accept the default values
for the quota options. The default values are as follows:
•
iunit
:
5000
•
bunit
:
100
•
itune
:
50
•
btune
:
50
See Section 5.7 for more information on quotas.
5.2.2.1 OST service ordering — SFS20 storage
You must plan the order in which you specify the LUNs for the OST services to the
create filesystem
command carefully, because this eventually determines how files are striped across the OST services and
thus affects file system performance. The link between how OST services are specified to the
create
filesystem
command and file system performance is explained as follows:
• The order in which you specify the OST services to the
create filesystem
command is the order
in which the OST services are included into the logical object volume (LOV) that describes the file
system.
• The order in which the OST services are included into the LOV determines the adjacency of the OST
services.
• Files are striped across adjacent OST services.
When you are being asked to specify the OST services, the
create filesystem
command lists the
available LUNs in the order that will achieve the recommended striping pattern.
The Smart Array 6404 adapter has four ports: A1, A2, B1, and B2. Each SFS20 array is connected to the
same port of the Smart Array 6404 adapters on each of the two servers in a server pair. The LUNs on the
arrays connected to ports A1 and B1 are preferred to the first server in the sever pair. The LUNs on the
arrays connected to ports A2 and B2 are preferred to the second server. This pattern is repeated if there are
additional Smart Array 6404 adapters and arrays (there can be two Smart Array adapters on each server).
When you are creating a file system, the
create filesystem
command lists all of the LUNs preferred
to the first server in the pair as the first LUNs available for the file system, followed by the LUNs preferred to
the second server, as shown in the following example. In the displayed LUN information, port A1 is referred
to as scsi-1/1 and port A2 as scsi-1/2; port B1 is referred to as scsi-2/1 and port B2 as scsi-2/2.