Application Notes Linux Device Mapper Multipath with Data Replication Solutions for HP StorageWorks EVA and XP disk arrays Part number: 5697-7807 First edition: October 2008
Legal and notice information © Copyright 2008 Hewlett-Packard Development Company, L.P.
Document overview This document helps you understand the concepts involved in using Device Mapper Multipath with storage replication solutions like Business Copy and Continuous Access for HP StorageWorks Enterprise Virtual Arrays and HP StorageWorks XP disk arrays. This includes recommendations for using Device Mapper Multipath in these environments.
Continuous Access remote replication software provides a continuous, non-disruptive, host-independent remote data replication solution for disaster recovery or data migration across geographically distant locations. Device Mapper is an infrastructure included in the Linux kernel that provides a generic way to create virtual layers of block devices. It supports striping, mirroring, snapshots, concatenation and multipathing.
Figure 1 Local replication environment Business Copy with HP StorageWorks Enterprise Virtual Arrays Business Copy solution enables you to create Snapclones, Snapshots, and Mirrorclones for local data replication. Linux Device Mapper Multipath supports usage of the data copies in a multipathed SAN environment. When a Business Copy object such as Snapclone or Snapshot of a Vdisk is created and discovered from the host, a new multipath device is created under the directory /dev/mapper.
#echo 1 > /sys/block//device/rescan 4. Create multipath device for the LU with the new host access permission. #multipath –v0 Continuous Access operations Data replication across data centers located miles apart is a desirable feature, given the size of the data and their criticality. This replication of data across geographically distant locations is provided by Continuous Access for HP StorageWorks disk arrays.
Site failover Failover of data from the source array to the destination array may be a planned or unplanned. Planned failover of source array may be due to a scheduled downtime at the local site like hardware maintenance, application maintenance, which needs the operations to be moved from local site to the remote site. Unplanned failover may be due to an unexpected loss of local site, due to hardware failure, natural disasters where the hardware components at the local site may not remain intact.
http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?conten tType=SupportManual&lang=en&cc=us&docIndexId=64179&taskId=135&prodTypeId=18964& prodSeriesId=315919 • HP StorageWorks Continuous Access EVA implementation guide http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?conten tType=SupportManual&lang=en&cc=us&docIndexId=64179&taskId=101&prodTypeId=18964& prodSeriesId=471572 • HP StorageWorks XP24000/XP20000 Business Copy Software User’s Guide http://h20000.www2.hp.
