The Persistent Reservations option lets you view and clear and associated . , which the cluster server software configures and manages, preserve logical drive reservations and logical drive registrations. Persistent reservations also prevent other from accessing the .
Attention:
Possible application errors – Persistent reservations are allowed on a in a , but they are not allowed on a . If a logical drive has any type of reservation when designated as a secondary logical drive, the primary logical drive detects a reservation conflict at its first write request to the secondary logical drive and clears the reservation automatically. Subsequent requests to place a reservation on the secondary logical drive are rejected.Keep these guidelines in mind when you create persistent reservations:
From the Logical/Physical tab, select any desired node, and select Advanced >> Maintenance >> Persistent Reservations . The dialog shows any logical drives in the storage subsystem that have registrations, with the first logical drive in the list highlighted by default.
The Persistent Reservation dialog shows any logical drives in the storage subsystem that have registrations, with the first logical drive in the list highlighted by default. If there are no logical drives with registrants, the dialog shows no data. This table describes the information and buttons shown in the Persistent Reservation dialog.
Information or Button | Description |
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Logical Drive Name | Shows the user label of the logical drive with persistent reservations. Logical drives are listed in alphabetical order. If a logical drive user label is not available, then its World Wide Identifier (WWID) appears. |
LUN | Shows the assigned LUN number for the particular logical drive. |
Registrations | Shows the number of registrations for the particular logical drive. |
Reservation Type | Shows an abbreviated form of the associated reservation type for the particular logical drive.
Each addressable logical drive can have one reservation. Each reservation can grant access rights to one or more registrants, depending on the reservation type. You can reserve a logical drive for a specific access level by a group of registrants. All of the registrants within a group are restricted to the access level defined by the reservation type. This list shows reservation types as follows:
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PTPL? | Shows Yes if the registrations are set to persist through a power loss. |
To view the registrations that are associated with the logical drive reservation, either double-click the desired logical drive, or highlight the logical drive and select the View Associated Registrations check box in the upper left of the dialog.
Important:
You may view only one registration for a logical drive at a time.This table describes the information that appears in the Persistent Reservation dialog that shows logical drive registrations.
Information | Description |
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Interface Type | Shows the type of interface: SATA, PATA, or Fibre. |
Host (Initiator) Port | Shows the associated user label for the particular host port. If the host port alias has not been provided, then Not Available appears. |
Associated Host | Shows the host associated with the specific logical drive. |
Controller (Target) Ports | Shows the port name of the target port. |
Holds Reservation? | Shows either Yes or No, depending on whether the specific HBA host port is the reservation holder.
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Use the Refresh option to update the reservation and registration view. An hourglass appears while the reservation and registration information is updated. The first logical drive in the list should be highlighted. If you selected the check box before you clicked Refresh, the check box stays selected. The reservation information shown in the bottom pane for the logical drive is highlighted.
Use the Save As option to save all reservation and registration information. All reservation and registration information for each logical drive is saved, no matter how many logical drives you have highlighted in the upper pane.
The Files of Type text box lists All Files (*.*) and Reservation data (*.txt). The Reservation data (*.txt) should be the default file shown. The file is saved as a .txt file, which is an ASCII representation of the registration and reservation information.
Logical drive reservation and registration data for HBA host ports no longer part of the configuration might be retained along with current registration and reservation data. Accumulation of the old data eventually can case the to reach the upper boundary of allowed HBA host ports and to issue an Insufficient Registrations Resources error if another HBA host port tries to register. The maximum number of registrants per logical drive is 512. The maximum number of registrants per storage subsystem of total registrations is 100,000.
Keep these guidelines in mind when you use the Clear option:
Use the Clear option to perform these functions:
The reservation and registrations that were associated with the logical drives that you highlighted in the upper pane are cleared.