EMC Symmetrix / DMX SRDF Setup

For this setup, let’s have two different host, our local host will be R1 (Source) volumes and our remote host will be R2 (Target) volumes.

A mix of R1 and R2 volumes can reside on the same symmetrix, in short you can configure SRDF between two Symmetrix machines to act as if one was local and other was remote and vice versa.  

Step 1

Create SYMCLI Device Groups. Each group can have one or more Symmetrix devices specified in it.

SYMCLI device group information (name of the group, type, members, and any associations) are maintained in the SYMAPI database.

In the following we will create a device group that includes two SRDF volumes.

SRDF operations can be performed from the local host that has access to the source volumes or the remote host that has access to the target volumes. Therefore, both hosts should have device groups defined. 

Complete the following steps on both the local and remote hosts.

a) Identify the SRDF source and target volumes available to your assigned hosts. Execute the following commands on both the local and remote hosts.

# symrdf list pd (execute on both local and remote hosts)

or

# syminq

b) To view all the RDF volumes configured in the Symmetrix use the following

# symrdf list dev

c) Display a synopsis of the symdg command and reference it in the following steps.

# symdg –h

d) List all device groups that are currently defined.

# symdg list

e) On the local host, create a device group of the type of RDF1. On the remote host, create a device group of the type RDF2.

# symdg –type RDF1 create newsrcdg (on local host)

# symdg –type RDF2 create newtgtdg (on remote host)

f) Verify that your device group was added to the SYMAPI database on both the local and remote hosts.

# symdg list

g) Add your two devices to your device group using the symld command. Again use (–h) for a synopsis of the command syntax.

On local host:

# symld –h

# symld –g newsrcdg add dev ###

or

# symld –g newsrcdg add pd Physicaldrive#

On remote host:

# symld –g newtgtdg add dev ###

or

# symld –g newtgtdg add pd Physicaldrive#

h) Using the syminq command, identify the gatekeeper devices. Determine if it is currently defined in the SYMAPI database, if not, define it, and associate it with your device group.

On local host:

# syminq

# symgate list (Check SYMAPI)

# symgate define pd Physicaldrive# (to define)

# symgate -g newsrcdg associate pd Physicaldrive# (to associate)

On remote host:

# syminq

# symgate list (Check SYMAPI)

# symgate define pd Physicaldrive# (to define)

# symgate -g newtgtdg associate pd Physicaldrive# (to associate)

i) Display your device groups. The output is verbose so pipe it to more.

On local host:

# symdg show newsrcdg |more

On remote host:

# symdg show newtgtdg | more

j) Display a synopsis of the symld command.

# symld -h

k) Rename DEV001 to NEWVOL1

On local host:

# symld –g newsrcdg rename DEV001 NEWVOL1

On remote host:

# symld –g newtgtdg rename DEV001 NEWVOL1

l) Display the device group on both the local and remote hosts.

On local host:

# symdg show newsrcdg |more

On remote host:

# symdg show newtgtdg | more

Step 2

Use the SYMCLI to display the status of the SRDF volumes in your device group.

a) If on the local host, check the status of your SRDF volumes using the following command:

# symrdf -g newsrcdg query

Step 3

Set the default device group. You can use the “Environmental Variables” option.

# set SYMCLI_DG=newsrcdg (on the local host)

# set SYMCLI_DG=newtgtdg (on the remote host)

a) Check the SYMCLI environment.

# symcli –def (on both the local and remote hosts)

b) Test to see if the SYMCLI_DG environment variable is working properly by performing a “query” without specifying the device group.

# symrdf query (on both the local and remote hosts)

Step 4 

Changing Operational mode. The operational mode for a device or group of devices can be set dynamically with the symrdf set mode command.

a) On the local host, change the mode of operation for one of your SRDF volumes to enable semi-synchronous operations. Verify results and change back to synchronous mode.

# symrdf set mode semi NEWVOL1

# symrdf query

# symrdf set mode sync NEWVOL1

# symrdf query

b) Change mode of operation to enable adaptive copy-disk mode for all devices in the device group. Verify that the mode change occurred and then disable adaptive copy.

# symrdf set mode acp disk

# symrdf query

# symrdf set mode acp off

# symrdf query

Step 5

Check the communications link between the local and remote Symmetrix.

a) From the local host, verify that the remote Symmetrix is “alive”. If the host is attached to multiple Symmetrix, you may have to specify the Symmetrix Serial Number (SSN) through the –sid option.

# symrdf ping [ -sid xx ] (xx=last two digits of the remote SSN)

b) From the local host, display the status of the Remote Link Directors.

# symcfg –RA all list

c) From the local host, display the activity on the Remote Link Directors.

# symstat -RA all –i 10 –c 2

Step 6 

Create a partition on each disk, format the partition and assign a filesystem to the partition. Add data on the R1 volumes defined in the newsrcdg device group. 

Step 7 

Suspend RDF Link and add data to filesystem. In this step we will suspend the SRDF link, add data to the filesystem and check for invalid tracks.

a) Check that the R1 and R2 volumes are fully synchronized.

# symrdf query

b) Suspend the link between the source and target volumes.

# symrdf suspend

c) Check link status.

# symrdf query

d) Add data to the filesystems.

e) Check for invalid tracks using the following command:

# symrdf query

f) Invalid tracks can also be displayed using the symdev show command. Execute the following command on one of the devices in your device group. Look at the Mirror set information.

On the local host:

# symdev show ###

g) From the local host, resume the link and monitor invalid tracks.

# symrdf resume

# symrdf query