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Name You can name the persistent image. This
becomes 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 capacity of the cache file
for that volume 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).
v
Delete an existing persistent image.
v
Modify properties of an existing persistent image, including read-only or
read-write, and retention value.
Schedules
Use this panel to schedule persistent images to be taken at specific times (this is
independent of the scheduled backup function through NAS Backup Assistant
described earlier). Each PSM schedule entry defines a set of persistent images to
be taken starting at a specified time and at a specified interval, with each image
having the set of properties defined in the entry. This allows you to customize
scheduled persistent images on a per-volume basis. For instance, you could set a
persistent image for one volume to occur every hour, and for another volume to
occur only once a day.
The set of properties you define are the same properties described in the Persistent
Images panel description assigned above; when you define these properties, all
persistent images created according to this schedule entry will be given those
properties. Once a scheduled persistent image is created, certain properties of that
persistent image can be modified through the Persistent Images panel,
independently of other persistent images created according to the schedule.
After you create a schedule entry, it appears in the list of scheduled persistent
images. Subsequently, you can modify the properties of an existing entry, such as
Chapter 6. Managing and protecting the network and storage
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