HP StorageWorks EVA replication software consolidated release notes (T3687-96056, February 2006)

3 HP StorageWorks Continuous
Access EVA 2.3
HP StorageWorks Continuous Access EVA 2.3 is a specific set of remote replication features enabled in
EVA controller software 5.1x. This chapter describes the remote replication enhancements, supported
features by controller software version, fixedissues,andworkarounds.
Remote re plication software enhancements
• VMware suppo
rt. Remote replication support for VMware 2.5.2 on all EVA array mo dels
is added.
• Increased replication performance. The buffer protocol has increased from 62 @ 8K bytes each to
124 @ 8K byte
s each. Both the source and destination arrays must be running controller software
VCS 4.0x or X
CS 5.1x to take advantage of this increase.
Protecting data against a site failure
When the destination array is unavailable and both controllers on the source array are restarted, host
presentation of source virtual disks is blocked. Host presentation of source virtual disks remains blocked
until the destination array becomes available (and can communicate with the source array) or you
suspend the DR group.
The purpose of blocking host presentation is to protect data during a site failure, where the potential
exists for both sides of the remote replication connection to be p resented to hosts simultaneously, and to
protect stretched cluster memb ers from being able to detect or access t wo copies of the same data. It also
protects boot-from-SAN servers from two hosts booting aga inst the same boot ima ge. While this behavior
may not be desired in all installations, it is necessary to protect data integrity.
You can check if host presentation is blocked in both HP Replication Solutions Manager and HP
Command View EVA.
In HP Replication Solutions Manager:
• On the General tab of the Virtual D isk Properties window, BLOCKED appears in the Operational
State box.
• On the General tab of the selected DR group window, BLOCKED appears in the Operational
State box.
In HP Command View EVA:
• On the Vdisk Active Members Properties page, None (DR members protected) appears in
theHostAccessbox.
• On the DR Group Properties page Blocked appears in the Group host access box.
To remove the host presentation block, suspend or repair the connection to the destination array.
HP StorageWorks EVA replication soft ware consolidated release notes (XCS 5.1x)
13