Avilt1
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NS20 code upgrade and Replication

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We have two NS20 devices with replication Version 1. We will be upgrading the NAS code on primary NS20 device and before the upgrade, I need to abort the replication as the new NAS code supports Version 2 replication. After the code upgrade on both the devices do I need to redefine the replication from the scratch? Or is it just going to continue?

Appreciate some can mail me the link for the technical material for replication version 2 through Celerra Manager.

Thanks

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Re: NS20 code upgrade and Replication

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In V1 the replication setup(defining file system) was done at remote server. But in V2, I think its on Source server. Am I correct?

Yes, this is correct.  The wizard will help you set up your interconnects, create the destination filesystem, run the full copy and start replication.

Also what is the command to monitor the replication progress OR % of replication that is complete? The command nas_replicate -info only shows the status of the replication.

Remember that before you can begin replication, you will be doing a nas_copy, not a nas_replicate.  You have to have a complete filesystem copy at the distant end before replication can begin.  So you can monitor this initial copy using the nas_copy command, not nas_replicate.

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Re: NS20 code upgrade and Replication

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If there are existing replicaion sessions, the automatic V1 to V2 conversion WILL NOT take place.  You can safely upgrade both sides to 5.6.  Once they are there, you can schedule a convenient time to do a V1 to V2 upgrade.
Avilt1
3 Argentium

Re: NS20 code upgrade and Replication

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"Once they are there, you can schedule a convenient time to do a V1 to V2 upgrade."

Could you please elaborate. Does it mean I have to remove the replication completely and then redefine the replication from the scratch?

Appreciate some URL link for RIP V2 thru celerra manager. Whats is the primary difference between V1 and V2?

In the new NAS code, Under Replications (Celerra manager) I see 3 tabs, Replications, Celerra Network Servers and Data Mover Interconnects. I do not see the Availabel Destinations which was available in V1. How do I setup replication in V2 thru Celerra manager?

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Re: NS20 code upgrade and Replication

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Avilt wrote:

"Once they are there, you can schedule a convenient time to do a V1 to V2 upgrade."

Could you please elaborate. Does it mean I have to remove the replication completely and then redefine the replication from the scratch?

Not at all.  Once you are ready, your local team will be able to help you run through a V1 to V2 upgrade.  This will preserve all your existing replication sessions; there is no need to delete them at all.

Appreciate some URL link for RIP V2 thru celerra manager.

While I don't have a manual specifically dedicated to Celerra Manager (the online help in Celerra Manager is very thorough), I do have a manual for Replication Version 2 which may help alleviate some of your concerns.  You can find it here: http://powerlink.emc.com/km/live1/en_US/Offering_Technical/Technical_Documentation/300-004-188.pdf

Whats is the primary difference between V1 and V2?

There are a tremendous number of improvements between version 1 and version 2.  Specifically, there are improvements in the following areas:

  • RepV2 can better keep a consistent baseline between the two sides because of a redesign of the replication checkpoint structure.
  • The use of "interconnects" removes the network link between the two Celerras from the replication function, allowing for more flexibility and stability
  • RepV2 allows for "switchover" and "failover" of filesystems; the former being graceful and preserving any data in flight, and the latter being graceless and losing any data in flight.  This allows for easy testing of your DR solution
  • Along with many other stability and serviceability enhancements.  It's also much easier to implement a replicated filesystem with V2.

In the new NAS code, Under Replications (Celerra manager) I see 3 tabs, Replications, Celerra Network Servers and Data Mover Interconnects. I do not see the Availabel Destinations which was available in V1. How do I setup replication in V2 thru Celerra manager?

When you are ready to perform the conversion from V1 to V2, your field support personnel or Authorised Service Representative will assist you with the transition.  You should then be able to see everything on your Celerra Manager sessions.  The manual above should help you understand how you will set up V2 sessions in the future, when your V2 conversion is complete.

Avilt1
3 Argentium

Re: NS20 code upgrade and Replication

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Thank You for the information. We have decided to remove the existing V1 replication completely and establish V2 replication to a new server.

I am trying to set this is up thru Celerra Manager. In V1 the replication setup(defining file system) was done at remote server. But in V2, I think its on Source server. Am I correct?

Also what is the command to monitor the replication progress OR % of replication that is complete? The command nas_replicate -info only shows the status of the replication.

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Re: NS20 code upgrade and Replication

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In V1 the replication setup(defining file system) was done at remote server. But in V2, I think its on Source server. Am I correct?

Yes, this is correct.  The wizard will help you set up your interconnects, create the destination filesystem, run the full copy and start replication.

Also what is the command to monitor the replication progress OR % of replication that is complete? The command nas_replicate -info only shows the status of the replication.

Remember that before you can begin replication, you will be doing a nas_copy, not a nas_replicate.  You have to have a complete filesystem copy at the distant end before replication can begin.  So you can monitor this initial copy using the nas_copy command, not nas_replicate.

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Avilt1
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Re: NS20 code upgrade and Replication

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Thank You.

I am looking for more information on "Data Mover Interconnect"

Whats is the purpose of Name Service Interface Names? What happens when this is not resolved to IP address?

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Re: NS20 code upgrade and Replication

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The original purpose of the DART Interconnect (DIC) system was to allow Data Movers to communicate using HTTP in a client/server relationship. Part of the interconnect mechanism creates system-generated passwd entries with names based on storage array backends. These new passwd entries (alias records) are used by DIC to authenticate requests between Data Movers using XML packets over HTTP. With NAS code version 5.6 and Replication Version 2, the interconnect framework is now used both for authentication and throttling information between Data Movers. Do not delete, or otherwise modify, these passwd entries.  Replication sessions will fail if these passwd entries are modified or deleted.
Peter_EMC
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Re: NS20 code upgrade and Replication

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Name Service Interface Names is like DNS for Interface Names.

If the interface name is not resolvable, the replication will not work, because the datamover does not know how to communicate with this interface.

To avoid resolving issues of interfaces use IP Addresses when configuring replication.

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Avilt1
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Re: NS20 code upgrade and Replication

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1. If I have more than 2 file systems to be configured for replication, what is the recommendation? Shall I define multiple "Data Mover Interconnect"?

2. I have 100mbps WAN bandwidth available between the source and remote site. One file system (500GB) configured for replication with default values. The current transfer rate is 724KBPS and the router bandwidth utlization is around 10Mbps. Can I force the replication to use more available bandwidth for quick completion of initial replication?

Thank You for your response.

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