EMC OpenMigrator Overview


Open Migrator/LM operates at the filter-driver level to manage and move Windows data from a source to a target volume with minimal disruption to the server or applications. Open Migrator/LM requires one potential restart of the server to install the application.


During and after migration, Open Migrator/LM captures all I/O to the source volume and writes it to both the source and the target volumes. Open Migrator/LM synchronizes the source volume and target volume until the final reboot


Note the following considerations for Open Migrator/LM:

  • Both source and target volumes remain synchronized until the migration is completed.

  • Windows NT file system (NTFS) can be migrated from smaller to larger volumes, or between equal-sized volumes. Open Migrator/LM adjusts the NTFS file systems automatically for the target volumes.

  • Open Migrator/LM does not support migration of FAT and FAT32 file systems.

  • Data migration for Microsoft Cluster Servers (MSCS) is supported. Open Migrator/LM can only be installed on a single node of a cluster.

  • Open Migrator/LM cannot be used with the following:
    • Microsoft Terminal Server
    • EMC Celerra® systems

  • Open Migrator/LM does not support boot or system volume migration.


Migration Persistence

Open Migrator/LM persists migrations across system reboots. If, in the course of copying data from the source to the target, the system experiences an outage, the software continues the migration from the place it left off prior to the disruption. Open Migrator/LM does not require any user intervention to continue after reboot. The Open Migrator/LM service and filter drivers automatically work together to complete the migration once the operating system (OS) loads and the respective disks become available to the system.


Migration persistence across reboot is not guaranteed for cluster migrations.


It highly recommended to keep all the cluster nodes up during MSCS migration. MSCS provides fail-over capability. When other cluster nodes are running while data is being migrated and the system is disrupted or restarted, migrations will fail immediately, and all participating devices are automatically failed-over to their designated nodes.


Mount Point Migration

When you reboot to complete the migration (at system boot time), the software's filter driver transfers the source volume's drive letter to the target volume. At system startup time, the Open Migrator/LM Service maps the mount points previously associated with the source volume to the target volume.


To ensure that all mount points are properly reassigned from the source volume to the target volume before users access them, you must add the Open Migrator/LM Service to the DependOnService list of any Windows Services using the source's mount points. For example, if the source volume has a mount point that is shared out, you must make the Lanmanager Service dependent on the Open Migrator/LM Service before this volume is migrated. Note: The above operation is not needed if the migration is completed manually by selecting "Complete migration". All mount points are moved to the target volume during the completing process.