Building Disaster Recovery Serviceguard Solutions Using Metrocluster with Continuous Access XP P9000 for Linux B.01.00.00

Takeover timeout for Continuous Access journal mode

A takeover timeout occurs when a package failover to the secondary site (SVOL) and Metrocluster

Continuous Access issues takeover (either swap or SVOL takeover) command on SVOL. If the

journal group pair is flushing the journal data from PVOL to SVOL and takeover timeout occurs,

the package does not start and the following situations occur:

• The device group pair state remains in PVOL-PAIR/SVOL-PAIR.

• The journal data is being transferred to the SVOL.

In this case, it is required to wait for the completion of the journal data flushing and the state for

every of the following:

• Primary site: PVOL-PAIR or PVOL-PSUS(E)

• Secondary site: SVOL-PSUS(SSWS) or SVOL-PSUE(SSWS)

At this point, use the FORCEFLAG to startup the package on SVOL site or (2) to fix the problem (if

any of Continuous Access links was failed) and resume the data replication with the following

procedures:

1. Split the device group pair completely (pairsplit -g <dg> -S).

2. Re-create a pair from original PVOL as source (use the paircreate command).

3. Startup package on PVOL site (or SVOL site).

PVOL-PAIR with SVOL-PSUS(SSWS) state for Continuous Access journal mode

PVOL-PAIR with SVOL-PSUS(SSWS) is an intermediate state. The following is one scenario that

leads to this state:

• At T1, device pair is in PVOL-PAIR/SVOL-PAIR and the AP value is 0 in SVOL site. In other

words, all Continuous Access links fail.

• At T2, package failovers from PVOL site to SVOL site. The Metrocluster Continuous Access

issues SVOL-Takeover at the SVOL site and the state will become SVOL-PSUS(SSWS) and

PVOL-PAIR.

• At T3, all Continuous Access links have been recovered. The state stays in SVOL-PSUS (SSWS)

and PVOL-PAIR. The duration the PVOL remains in PAIR state is relatively short

The PVOL-PAIR/SVOL-PSUS (SSWS) is an invalid state for XP or P9000 Asynchronous (both

Continuous Access/Asynchronous and Continuous Access Journal). In this state, by running the

pairresync or takeover command, will fail. It is necessary to wait for the PVOL to become

PSUE.

Administering Metrocluster with Serviceguard Manager

Follow the steps described here to administer Metrocluster or the packages configured under

Metrocluster using Serviceguard Manager.

1. Access one of the node’s System Management Home Page at http://<nodename>:2301.

2. Click Tools, if Serviceguard is installed, one of the widgets will have Serviceguard as an

option. Click the ‘Serviceguard Manager’ link.

3. On the Cluster’s Home Page, click the Administration Tab and select the required options.

Different administrative options are listed below. Select the appropriate packages for the

required option.

Rolling upgrade

Metrocluster configurations follow the HP Serviceguard rolling upgrade procedure. The HP

Serviceguard documentation includes rolling upgrade procedures to upgrade the Serviceguard

version, the operating environment, and other software. This Serviceguard procedure, along with

recommendations, guidelines, and limitations, is applicable to Metrocluster. For more information

44 Administering Metrocluster