ONTAP Discussions

Snapmirror over WAN on specific VLAN

CARL_JOHNSTON
3,148 Views

Hi, All.

Data Ontap v7.3.6

I have two Filers separated over a WAN, both of which are configured with a local production IP address (for CIFS access, etc) and a replication IP address (on a stretched VLAN) per controller. I'm trying to set up a Snapmirror relationship between Filer1 and Filer2 (controller B, in both cases) and need to ensure that all replication traffic is routed via the replication VLAN (a requirement of the business I work for is that any replication traffic has to be segregated). Unfortunately, traffic is also routed between VLANs 80 and 46 so, theoretically, replication packets could be sent down either route.

Example rc configs as follows:

FILER1, Controller BFILER2, Controller B

hostname FILER1B

ifconfig e0a down

ifconfig e0b down

vif create lacp VIF1B -b ip e0a e0b

vlan create VIF1B 80 708

ifconfig VIF1B-80 `hostname`-NAS02Team netmask 255.255.252.0 partner VIF1A

ifconfig VIF1B-708 192.168.13.106 netmask 255.255.255.248

route add default 49.14.80.1 1

routed off

options dns.enable on

options nis.enable off

savecore

hostname FILER2B

ifconfig e0a down

ifconfig e0b down

vif create lacp VIF2B -b ip e0a e0b

vlan create VIF2B 46 708

ifconfig VIF2B-80 `hostname`-NAS02Team netmask 255.255.252.0 partner VIF2A

ifconfig VIF2B-708 192.168.13.108 netmask 255.255.255.248

route add default 49.14.80.1 1

routed off

options dns.enable on

options nis.enable off

savecore

I can set up a standard Snapmirror relationship but I don't know how to force the traffic over VLAN 708? I've tried adding the following above the Snapmirror relationship in the snapmirror.conf file, but I don't know whether the entry is valid or if the syntax is correct?

rep_path = multi(192.168.13.106,192.168.13.108)

FILER1B:testvol1 FILER2B:testvol1_SnapMirror - - - - -

A further complication is that the Network Team are unable to verify which route the replication traffic is taking on the WANScalers. At least if I know my config is correct, I can rest easy (and if anyone knows of any logs etc that would help me verify which route the replication data is taking, I would be very grateful).

Thank you,

Carl

3 REPLIES 3

mwalters
3,148 Views

Not sure about the rep_path you put there.....I haven't come across that syntax in SnapMirror, I reckon you are making that up 🙂

For SnapMirror using CLI, it is a "pull" operation. (this may be obvious!).  

So on the destination controller you edit the snapmirror.conf file.

The path chosen is how the filer name is resolved from the names used in there.  In other words, how the secondary will resolve the source filer name you give (& the first entry - your "FILER1B" - need not be the actual controller name....and indeed to control the link when you have multiple paths, probably would NOT be the controller name),   

This is the key.

If you put the start of the config file as

     FILER1B:testvol1 FILER2B:testvol1_SnapMirror - - - - -

then IF FILER1B is resolved over VLAN 708 from 2B, you are home & dry !

Of course you can always cheat and use the actual IP address in there too !

IF there are multiple paths that can be used given the IP address, then I would suggest you have a "bad" network configuration....

cheers

CARL_JOHNSTON
3,148 Views

Thanks for the swift response and advice.

I have got this working in a very basic fashion using the VLAN 708 IP address of the host system instead of the 'FILER1B' hostname, as suggested. Using the 'ifstat -a' command whilst the replication is being performed, I can see that the transfer of data is occurring over the replication VLAN, so all good.

My only gripe is that if I set up the relationship this way, I can't manage it from the GUI utils.

I'm led to believe that the 'rep_path' syntax is a possible option in the snapmirror.conf file but is specific to multi-pathing. The syntax is as follows and the option goes above the line that defines the snapmirror relationship:

name = mode (src_filer1, dest_filer1) (src_filer2, dest_filer2)

I read somewhere that I could ommit the second parentheses option to leave a single path, but am not sure whether this is valid in my situation. I'll do some more testing and will report back...

Thanks again,

Carl

mwalters
3,148 Views

cool....let us know how you get on: I have not heard of the "rep_path" option before, & couldn't find anything on the support site to suggest it exists, but if you find out more, please tell !!

cheers

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