IBM TotalStorage 201, Руководство пользователя

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Persistent Images
This panel lists all of the persistent images that exist on all volumes. On this panel
you can:
v
Create a new persistent image immediately (without scheduling it via the
Schedules panel).
v
Delete an existing persistent image.
v
Modify properties of an existing persistent image, including read-only or
read-write, and retention value.
When you create the persistent image, you can specify properties for the persistent
image, including:
Volume(s) The persistent image can contain a single volume
or multiple volumes. To select multiple volumes,
hold down the Ctrl key while clicking on the
volumes you wish to select. For multi-volume
persistent images, a virtual directory containing data
for a volume will appear under the persistent image
directory in the top level of each volume in the
persistent image (the name of the persistent image
directory is configured in the Global Settings panel).
Name You can name the persistent image. This will be the
name of the virtual directory containing the
persistent image, underneath the persistent image
directory in the top level of the volume (the name of
the persistent image directory is configured in the
Global Settings panel).
Read-only or read-write A persistent image is read-only by default, so no
modifications can be made to it. However, you can
set the persistent image to read-write, which
permits you to modify it. When a persistent image is
written, the modifications made are also persistent
(they survive a reboot of the system). Changing a
persistent image from read-write to read-only resets
the persistent image to its state at the time you took
the persistent image, as does selecting Undo
Writes for a read-write persistent image from the
Persistent Images panel.
Retention value A persistent image can be given a relative retention
value or weight. This is important when PSM needs
to delete some persistent images for a volume
because the cache file for the volume for which the
persistent image was taken capacity has reached a
certain threshold, as described later in this section.
If the volume cache file completely fills, then all
persistent images for that volume are deleted
regardless of the retention values. By default, a
new persistent image is assigned a “Normal”
retention value (there are other higher and lower
values which can be selected).
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NAS 200 User’s Reference