HP StorageWorks Continuous Access EVA Administrator Guide (T3687-96043, December 2005)

Fail back to the
original source
Possible scena
rio: You are operating from an array that is not the original source (designated Home in
the replicati
on manager). You need to move operations from the remote array back to the local array.
Action summar
y: Prepare the source array for the failover and fail over the destination (original source)
DR group. Fail
back (also known as reverting to Home) is similar to a planned failover. Fifteen minutes
after failin
g over from a source to a destination array, you ca n fail back in the other direction.
Procedure:
1. If desired, move storage managem ent to another ma nagement server. For instructions, see HP
Command View
EVA user guide.
2. Ensure that
all DR groups are resumed and fully normalized. If a DR group is merging or a full copy
is in progre
ss, wait for the process to complete.
3. Stop all ho
stI/Oonthecurrentsourcearray.
Foralloperatingsystems,includingVMwareVirtualOSs,butexcludingWindows,stopallI/Oto
the virtual disks in source DR groups and unmount associated volumes or file systems.
For VM ware, also shut down each virtual machine on the VMware server, and either leave the virtual
machines o
ff until you fail back the LUNs, or, using the VM configuration editor, remove all LUN
assignme
nts in the ha rdwa re configuration files.
For Windo
ws, flush all cache files a nd shut down the operating system. Small files held in Windows
cache can disrupt remote replication. Reboot the host as Windows requires; HP Continuous Access
EVA is n eutral to rebooting the host.
4. Fail over the destination (original source) DR groups (or perform "revert to H om e " in the replication
manager
).
5. Issue o
perating system commands to resume I/O to the new (original) source. See Resuming I/O
after f
ailover.
Return operations to new hardware
Possible scenario: Some type of disaster (lightning, flood, fire, severe equipment failure, or so on)
damaged local equipment and forced a failover to a remote site. Hardware on the local source array
was replaced. The new hardware now acts as the destination array and you are operating from an array
that is not the original source (designated as H om e) .
Action summary: When the damaged components at the local site (hosts, array controllers, or switches,
for example) are repaired, and the site is operational and back online, fail over to new hardware at the
local site. Figure 10 diagrams the steps to return operations to new hardware.
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Failover and recovery