Accepted Solution

Semi-Sync Snapmirror

[ Edited ]

Hello All,

I have configured Semi-Sync Snapmirror between two vfilers located in different datacenters. The initial sync was successful, but after that it keep throwing this error on the destination

[dest_vfiler: ipmultipath.setup.connFailed:warning]: IP Multipath failed to connect to source_vfiler.

Wed Feb 15 05:48:04 GMT [dest_vfiler: replication.dst.err:error]: SnapMirror: destination transfer from source_vfiler:source_vol1 to dest_vol1 : Error in snapmirror sync mode negotiation

When i looked up the NOW Knowledge base, the solution was to update the /etc/hosts file on both the source and destination filer to include the IP address of opposite filer. but still it is not working. Is there any step i am i missing in configuring the snapmirror semi-sync



Re: Semi-Sync Snapmirror

Does async snapmirror work between the two?

It sounds like an address resolution issue…but be interesting if Async works…

Re: Semi-Sync Snapmirror


Hows your subnets?

Source and destination must be in a different subnets.

And that "Error in snapmirror sync mode negotiaton" What is the size of the volume, it needs to be at least 10GB, is it smaller than that?


Re: Semi-Sync Snapmirror

Yes.. Async works between the source and destination.

Re: Semi-Sync Snapmirror

They are in different subnets and in different datacenter (in different cities)

The Vol size is 2TB.

Re: Semi-Sync Snapmirror

i'm thinking maybe some kind of latency issue  based on that then...if Async works then i'd suggest everything else is OK between the filers... however not sure if semi sync is latency sensitive in the way synchronous would be...

maybe worth checking that out tho...

Re: Semi-Sync Snapmirror

Have you checkd your firewall settings?


Configuring SnapMirror through a firewall.


All forms of SnapMirror and SnapVault use the standard bind/listen/accept sequence on a TCP socket. In an asynchronous SnapMirror or SnapVault relationship, the primary filer listens on TCP port 10566. The secondary filer, using an available user port (1024-65535), will connect to the primary filer or OSSV client on TCP port 10566 to initiate a transfer.

The firewall does not need to be open on ports 1024-65535.

If multi-path is configured for SnapMirror, then the secondary filer will also listen on TCP port 10565 for the additional multi-path connections.

Synchronous SnapMirror requires additional TCP ports, 10567 through 10569. For a Synchronous SnapMirror relationship the primary filer will listen on TCP ports 10566 and 10569. The secondary filer listens on TCP ports 10565, 10567 and 10568.

OSSV clients and Filers also allow for NDMP management of SnapMirror and SnapVault. Both primary and secondary systems listen on Port 10000 for NDMP communications. OSSV's NDMP listening port may be configured to any desired and unused TCP port.

An important consideration when configuring the firewall is to allow the socket connections to be initiated in either direction to allow the SnapMirror relationships to be reversed as needed or SnapVault data to be restored.

TCP Listening Port Primary System Secondary Filer
10000 X X
10565 X
10566 X
10567 X
10568 X
10569 X


Re: Semi-Sync Snapmirror

Okie... It seems that Snapmirror Sync (& Semi-Sync) is not supported on Vfiler or on a volume where de-duplication is enabled. Snapmirror Sync ( & Semi-Sync) works only on physical storage (both source & destination)