HP StorageWorks P9000 User Manual page 47

The P-VOL Fence Level setting, which you specify during the Paircreate operation, determines
whether the host is denied access or continues to access the P-VOL when a Continuous Access
Synchronous pair is suspended due to an error. You will select one of the following Fence Level
settings:
Data: the P-VOL is fenced if an update copy operation fails. "Data" ensures that the S-VOL
remains identical to the P-VOL. This is done by preventing the host from writing to the P-VOL
during a failure. This setting should be considered for the most critical volumes for disaster
recovery. This setting reduces the amount of time required to analyze the currency of the S-VOL
during disaster recovery efforts. This setting is also designed for applications that can continue
to operate with another device pair.
Status: the P-VOL is fenced only if the primary system is not able to change S-VOL status to
suspended when an update copy operation fails. If the primary system successfully changes
S-VOL pair status to suspended, subsequent write I/O operations to the P-VOL will be accepted
and the system will keep track of updates to the P-VOL. This allows the pair to be resynchronized
quickly. This setting also reduces the amount of time required to analyze S-VOL currency during
disaster recovery.
Never: the P-VOL is never fenced. This setting should be used when I/O performance outweighs
data recovery. "Never" ensures that the P-VOL remains available to applications for updates,
even if all Continuous Access Synchronous copy operations have failed. The S-VOL may no
longer be in sync with the P-VOL, but the primary system keeps track of updates to the P-VOL
while the pair is suspended. Host failover capability is essential if this Fence Level setting is
used. For disaster recovery, the currency of the S-VOL is determined by using the sense
information transferred via host failover or by comparing the S-VOL contents with other files
confirmed to be current.
Procedure 5 To create one or more initial copies
1. On the menu bar, click Actions > Remote Copy > Continuous Access Synchronous > Pair
Operation. The Pair Operation window opens.
2. Change to Modify mode by clicking the
3. In the tree, select the CU grouping, CU, port, or host group in which the LU or LUs are located
that you want to pair.
4. From the list, select the LU or LUs to be paired. The volume(s) must be in SMPL status.
5. Right-click the selections and click Paircreate. The Paircreate dialog box displays.
The P-VOL field displays the selected volume's port number, GID, LUN, CLPR number,
and CLPR name.
◦ A pound symbol (#) at the end (00:00:3C #) indicates an external volume.
◦ If an X at the end (00:00:3C X) indicates a Thin Provisioning virtual volume.
If you selected more than one P-VOL, the P-VOL with the lowest LUN is displayed.
6. Assign an S-VOL by selecting the port, GID, and LUN from the S-VOL list, left to right. If you
selected multiple volumes as P-VOLs, specify the S-VOL for the P-VOL that is displayed.
Volumes for the subsequent S-VOL are automatically assigned according to LUN. If an S-VOL
is not available, you will have to create the pair individually. For an in-depth explanation, see
the bullet on creating multiple pairs in
7. From the RCU list, select the secondary system in which the paired S-VOL(s) are located.
For CU Free: the serial number, LDKC number, Controller ID, model name, Path Group
ID, and path type are displayed.
For specific CUs: the serial number, LDKC number, CU number, SSID, and path type are
displayed for CU excepting CU Free.
icon.
"Planning volume pairs" (page 17).
Create pairs 47