Building Disaster Recovery Serviceguard Solutions Using Metrocluster with Continuous Access XP P9000 for Linux B.12.00.00

Maintaining a cluster that uses Metrocluster with Continuous Access XP P9000 for
Linux
In normal operation, the Metrocluster with Continuous Access for P9000 and XP starts like any
other cluster, runs and halts packages in the same way as a standard cluster. However, startup
time for packages might be considerably slower because of the, must verify, disk status on both
disk arrays.
While the cluster is running, performing manual “changes of state” for devices on the XP or P9000
Series disk array can cause unexpected pair states for the device group preventing successful
package failover. In general, manual “changes of state” must not be performed while the package
and the cluster is running.
NOTE: However manual changes can be made when data protection must be restored manually
for a device group. For Example, if a package starts up with data replication suspended, a user
can perform a pairresync command to re-establish data replication while the package is still
running.
Viewing the progress of copy operations
While a copy is in progress between XP or P9000 arrays (that is, the volumes are in a COPY state),
the progress of the copy can be viewed by monitoring the % column in the output of the
pairdisplay command:
# pairdisplay -g pkgB -fc -CLI
Group PairVol L/R Port# TID LU Seq# LDEV# P/S Status Fence % P-LDEV# M
pkgB pkgD-disk0 L CL1-C 0 3 35422 463 PVOL COPY NEVER 79 460 -
pkgB pkgD-disk0 R CL1-F 0 3 35663 3 SVOL COPY NEVER - 0 -
This display shows that 79% of a current copy operation has completed. Synchronous fence levels
(NEVER and DATA) show 100% in this column when the volumes are in a PAIR state.
Viewing side file size
If you are using asynchronous data replication, you can see the current size of the side file when
the volumes are in a PAIR state by using the pairdisplay command. The following output,
obtained during normal cluster operation, shows the percentage of the side file that is full:
# pairdisplay -g pkgB -fc -CLI
Group PairVol L/R Port# TID LU Seq# LDEV# P/S Status Fence % P-LDEV# M
pkgB pkgD-disk0 L CL1-C 0 3 35422 463 PVOL PAIR ASYNC 35 3 -
pkgB pkgD-disk0 R CL1-F 0 3 35663 3 SVOL PAIR ASYNC 0 463 -
This output shows that 35% of the side file is full.
When volumes are in a COPY state, the % column shows the progress of the copying between the
XP or P9000 frames, until it reaches 100%, at which point the display reverts to showing the side
file usage in the PAIR state.
Viewing the Continuous Access journal status
The following two sections describe using the pairdisplay and raidvchkscan commands for
viewing the Continuous Access Journal Status.
Viewing the pair and journal group information using the “ pairdisplay” command
The command option “-fe” is added to the Raid Manager pairdisplay command. This option
is used to display the Journal Group ID (and other data) of a device group pair. The Journal Group
ID shows ‘-’ if the device pair is not in Continuous Access Journal mode. Otherwise, it shows a
number.
An example of the pairdisplay command with the “-fe” is as below:
Administering a Metrocluster using Continuous Access XP/P9000 replication 41