Setting up a basic SnapMirror operation

Make sure you have purchased a SnapMirror license for both the source and destination systems.

In both the source system and the destination system consoles, use the license add command to enable the SnapMirror license on the source and destination systems.

license add snapmirror_license_code

For more information see Entering license codes.

On the source system console, use the options snapmirror.access command to specify the host names of systems that are allowed to copy data directly from the source system. For example:

options snapmirror.access host=d_systemA

For more information see How to specify destination systems on the source system.

Through the Data ONTAP AdminHost, create or edit the /etc/snapmirror.conf file on the destination system to specify the volumes and qtrees to be copied and the schedule (minute hour day_of_month day_of_week or sync) on which the destination is updated. For example, the following entry specifies Snapshot mirroring from volume 0 of s_systemA to volume 1 of d_systemA at a maximum of 2,000 kilobits per second 15 minutes past every hour, Monday through Friday:

s_systemA:vol0 d_systemA:vol1 kbs=2000,restart=always 15 
* * 1,2,3,4,5

If you want to synchronously mirror volume 0 to volume 1, you use a command similar to the following:

s_systemA:vol0 d_systemA:vol1 - sync

For more information on schedule entries in the destination system's /etc/snapmirror.conf file, see Defining source and destination through snapmirror.conf and the na_snapmirror.conf(5) man page.

In both the source system and destination system console, use the snapmirror on command to enable SnapMirror on the source and destination systems.

For more information, see Enabling SnapMirror.

Prepare the destination system appropriately, depending on whether you are setting up SnapMirror volume or qtree replication.

• If you are setting up SnapMirror volume replication, in the destination system console, use the vol create command to create a volume to be the destination for the volume on the source, then use the vol restrict command to mark the volume as restricted.
• If you are setting up SnapMirror qtree replication, make sure that the volume on the destination system where you want to replicate a qtree with SnapMirror is online and not restricted. Do not manually create a destination qtree.

For more information, see the information about creating volumes in the volume management chapter of the Storage Management Guide; and see the information on restricting volumes in How to initialize a SnapMirror destination.

In the destination system console, use the snapmirror initialize command to create an initial complete (baseline) copy of the source on the destination and start the mirroring process.

SnapMirror volume replication example

Invoking the following command line transfers a complete copy of the source volume (vol0 on systemA) to the destination volume (vol2 on systemB). The destination volume must be configured as restricted and read-only.

snapmirror initialize -S systemA:vol0 systemB:vol2

SnapMirror qtree replication example

Invoking the following command line creates a destination qtree (qtree4 on vol1on systemB) and transfers a complete copy of the qtree source (qtree4 on vol1 on systemA) to that destination qtree. The volume in which the destination qtree is created must be online and writable.

snapmirror initialize -S systemA:/vol/vol1/qtree4 
systemB:/vol/vol1/qtree4

After you invoke the snapmirror initialize command, the scheduled Snapshot mirroring that you specified in Step 4 will automatically update the destination volume or qtree at the specified times.

See Initializing a SnapMirror destination for more information.

In the event that the SnapMirror source volume or qtree is disabled, you can use the snapmirror break command to make the destination volume or qtree writable and able to provide continuous file and data service to the clients who are no longer able to access the disabled source system. For more information, see Converting a destination to a writable volume or qtree.

On the administration host, edit the snapmirror.conf file on the destination system to change the schedule to sync.

Result

Data ONTAP uses the new schedule to change the asynchronous SnapMirror to a synchronous SnapMirror.

Install the Fibre Channel adapters in the source and destination systems. See the hardware and service guide for your storage system for installation instructions and the System Configuration Guide to ensure you install the adapter in the correct slot.

Connect the systems to Fibre Channel switches. See the hardware and service guide for more information.

On the console of each switch, configure the switch for a default configuration with no zoning and add long-distance Extended Fabric keys. See your switch documentation for configuration information.

Note
Ensure that the Fibre Channel switches are in fabric mode and support the Simple Name Service (SNS) protocol with support for symbolic names.

Example

The following Brocade switch commands might be used to configure a Brocade switch:

switch_con> switchdisable

switch_con> configdefault

switch_con> fastboot

Reboot both systems.

Configure the Fibre Channel adapter on each system by entering the following command at the console for each system:

ifconfig qlXa ipaddr netmask 255.255.255.0 up

X is the system slot number.

a is either port a or port b (labeled on the adapter).

ipaddr is the IP address of the adapter.

Note
Ensure that IP addresses for the ports on the same fabric have the same net number.

Example

The following commands configure port a of two Fibre Channel adapters. The net address is 10.10.10.0.

On system A:

ifconfig ql3a 10.10.10.24 netmask 255.255.255.0 up

On system B:

ifconfig ql3a 10.10.20.24 netmask 255.255.255.0 up

Ensure that the two systems can communcate by using the ping command.

Example

The IP address on the destination system is 10.10.20.24.

source> ping 10.10.20.24

10.10.20.24 is alive

Follow the steps in Completing a basic SnapMirror setup to complete the SnapMirror setup.

The cable from the Fibre Channel adapter to the Fibre Channel switch is disconnected.

Connect the cable to the switch.

The Inter Switch Link (ISL) connecting the two Fibre Channel switches is disconnected.

Connect the ISL.

The snapmirror.conf file specifies an IP address or host name that is not configured on the Fibre Channel fabric.

Edit the snapmirror.conf file to use the correct IP address or host name.

The host name used in the snapmirror.conf file does not match the IP address in the /etc/hosts file on the storage system.

Ensure that the IP addresses used for the hosts on the Fibre Channel fabric are all in the same subnet.