Communicating With A Partner Host - Cisco UCS Administration Manual

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The first replication that is performed on a pairing is always a FULL replication. Subsequent replications
Note
reflect the delta, except where an "Update Partner" operation is performed. In that case, the immediate
next replication would become a FULL replication.

Communicating with a Partner Host

To perform replication successfully, there must be a way for communicating between the local LUN and
the remote replication site to establish that the client (local Cisco Array) is allowed to invoke commands
on the server (remote replication site).
The Cisco Array uses the standard remote shell facility, ssh, leveraging on password-less access after
putting its public key to the proper location at the remote replication site.
For LUNs, Cisco supports open-target Async Replication. It can duplicate to the following platforms:
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Cisco UCS Invicta Scaling System Administration and Configuration Guide, Version 5.0.1.1a
5-2
During the replication process, the Destination LUN will be unmapped and unmounted and is,
therefore, inaccessible. This state prevents possible corruption of the Source data. The replication
process will automatically remap and remount at its completion. The Source SSR will continue to
have access to the Source LUN throughout the replication process.
Right-click a pairing in the list to display pairing menu options to: Delete, Verify Partner, Update
Partner, Schedule, Restore (always the entire LUN), or View Log File.
On mouse hover, the replication schedule for that LUN pairing appears in a pop-up box.
Once Async Replication pairing is setup, the "Increase in Size" and "Delete" operations are not
permitted on the Source LUN used for the pairing.
A LUN that has been configured as a Mirror is not supported to be used either as an Async Source
or Destination for performing Async Replication.
When restoring the Source LUN, the Restore process will unexport and unmount the LUN and it will
not be accessible. The Restore process will automatically re-mount and re-export at its completion.
Pairing setup, configuration, and scheduling applies to the current SSR only and is not accessible
from other SSRs.
If a host and/or device is not detected when checked, the respective fields turn red. The following
actions trigger checks: page refresh, new host pairing creation, pairing deletion, pairing host update
(check is performed on a specific update entry), manual replication scheduling and replication
termination.
Device column displays in green for a replication that is in progress and tan when a restore is in
progress.
When scheduling an Async Replication, note that the higher the thread numbers the higher the
throughput the greater the impact on system processing. The default is two. Initial transmission
block size parameter is used for the initial replication for a device, (including if the initial replication
is manually triggered). Subsequent delta replications for the device always use a 1Mb block size.
We do not recommend running several simultaneous replications and / or concurrent restores as
these operations will have a severe performance impact on the Source and or Destination devices.
Cisco Array
Linux systems:
Chapter 5 Asynchronous Replication