Dell PowerVault 715N (Rackmount NAS Appliance) - Manual (Page 53)

Undoing Writes to a Read/Write Persistent Image
To undo writes to a read/write persistent image, you must select an item from the Persistent Images list, and then click
Undo in the Tasks list.
To undo persistent image writes, perform the following steps:
1. On the NAS Manager primary menu, click Disks.
2. Click ActiveArchive, and then click Persistent Images.
3. On the Persistent Images page, click the radio button next to the persistent image to be restored to its original
state.
4. Click OK to restore the image or Cancel to leave it intact.
Setting Persistent Image Retention Weights and Read Only or
Read/Write Attributes
To change the read only or read/write attribute or the retention weight (deletion priority) of an image, you must edit the
persistent image properties by selecting an image from the Persistent Image list, and then clicking Properties in the
Tasks list.
To edit the persistent image properties, perform the following steps:
1. On the NAS Manager primary menu, click Disks, and then click Persistent Images.
2. In the list of persistent images, click the checkbox next to the persistent image you are editing.
3. In the Task list, click Properties....
4. Select the Read Only or Read/Write attribute.
5. Select the Retention weight.
6. Click OK to update the persistent image.
Configuring the Persistent Image Global Settings
You can modify the various aspects of the persistent image environment by performing the following steps:
1. On the NAS Manager primary menu, click Disks, and then click ActiveArchive.
2. Click Global Settings, and then configure the following options.
NOTE: Before changing the Image Directory Name, you must delete all existing persistent images.
Maximum Persistent Images — Specifies the maximum number of active persistent images per volume,
up to a maximum of 250. When the volume has 250 persistent images stored, starting another persistent
image overwrites the oldest persistent image with the lowest retention weight.
Inactive Period — Prior to starting a persistent image, the system waits for a period of relative inactivity on
the volume being imaged. The default value for this period, which is 5 seconds, allows systems to start an
image with a consistent file set and a minimal time-out. Experienced administrators may reduce or increase
this value for system optimization. Reducing the inactive period allows persistent images to begin on systems
where disk inactivity is rare, at the possible expense of synchronization problems within applications that are
concurrently writing to multiple files.
Inactive Time-Out — Specifies the amount of time the server continues to retry to create a persistent
image (default time is 15 minutes). A persistent image cannot start until a period of relative inactivity,
specified by the Inactive Period, occurs. If an interval longer than Inactive Time-Out passes before the
persistent image can begin, the persistent image cannot be taken and an error is displayed in the NAS
Manager status indicator and logged in the event log.
Image Directory Name — Specifies the directory name which is to be used for the persistent image mount