4-1-1 creating a file system with a volume manager – HP StorageWorks XP48 Disk Array User Manual
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Using Provisioning Manager 46
The process of creating a file system differs depending on whether Hitachi Dynamic Link Manager (HDLM)
software is installed on the host, and on whether a volume manager is to be used to manage the file system
being created.
A subsystem volume (LU) allocated to a host is treated as a raw device by the host. When HDLM is not used, a
single raw device is mapped to a single LU. If HDLM is used (when multiple paths exist between the host and
the subsystem), the same number of raw devices as paths are created, and all of these raw devices are
mapped to a single LU.
This is explained below, with the explanation divided up according to whether or not a volume manager is used.
3-4-1-1 Creating a File System With a Volume Manager
If a volume manager is being used, the process of creating a file system is performed as described below.
The volume manager builds a single volume group from the single raw device or from the HDLM device as a
single physical device. It then creates a single logical volume in that volume group. This logical volume is
treated as a device file, and the file system is created for this device file.
shows the relationship between the file system and device file that can be seen from the host, and
the LU in the subsystem. This figure assumes that there are two paths between the host and the subsystem LU
for when HDLM is being used
Figure 3-8
Host File System/Device File and Subsystem LU (with Volume Manager)
3-4-1-2 Creating a File System Without a Volume Manager
If a volume manager is not being used, the process of creating a file system is performed as described below.
•
When HDLM is not being used, the raw device corresponding to the specified LU is treated as a device
file, and the file system is created for this device file.
•
When HDLM is being used, a single HDLM device is created by consolidating the multiple raw devices
associated with the specified LU. This HDLM device is treated as a device file, and the file system is
created for this device file.