SAN Implementation Storage System Configuration

FC and IP SAN Storage System Configuration Basics

FC SAN:

[1] Verify SAN topology:

fcp config command used to ensure that the ports are configured according to the requirements decided upon during the SAN design phase.  If onboard FC ports are being used, the FC port behavior may have to be set.  If the FC ports connect to disk shelves, the port type needs to be set to FC Initiator while if they connect to the SAN fabric or the host, the behavior needs to be set to FC target.

[2] Enable FCP protocol:

First run the license command to see the available licenses.  You can use license add to add subsequent licenses.  To enable the FCP use fcp start command.  Finally, to verify the status use fcp status command.

[3] Port behvior set:

The adapter must be taken offline.  Use fcp config command followed by the adapter name and the down option.  To set the behavior of the FC ports use the fcadmin config -t [initiator|target]  command.  In order for changes to take affect the system must be rebooted.


[4] cfmode checked and set:

To check which cfmode is being used use the fcp show cfmode command.  There are several things to consider, [1] storage system, [2] host operating system, [3] DataONTAP version, [4] topology features.  There are 4 cfmodes:  [1] Single_Image; [2] partner; [3] dual fabric; [4] stand by.  The Single_Image is the default and recommended for DataONTAP 7.2+ systems.

To set cfmode, the privilge level commands need to be accessed:  priv set advanced
Then the FCP must be stopped: fcp stop
Next use the fcp set cfmode command to change modes
Then restart the FCP with fcp start


[5] WWPN:

To recorde the FC WWPN use:  fcp show adapters and fcp show nodename commands


[6] Check port configuration:

Verify the FC ports are online and speed and media type are correct, use the DataONTAP fcp config commands to verify these values.  By default they are set to AUTO for autonegotiate.  You can manually set the type if the FC switch port or host cannot autoneg (rare).


[7] Create aggr/vol:

Create appropriate aggr and volumes, ensure sizes of volumes is large enough for all LUNs and snapshots if using.  Also, the Unicode format must be enabled for volumes containing LUNs: vol options create_unicode on 




iSCSI SAN:


[1] Check Ethernet interfaces:

To bring up the interfaces, use ifconfig -a to view available interfaces.  Run the ifconfig up|down to bring up the interfaces.  Ensure proper configuration with IPADDR and NETMASK, ensure speed set to autoneg or to same speed as network.  If these changes need to be persisted across reboots, the /etc/rc and /etc/hosts files need to be updated.

[2] License and enable iSCSI:

Run the license command to see available package licenses.  Run the iscsi start, iscsi status commands to start and verify the startup of iSCSI on the filer.

[3] Configure iSCSI Ethernet interfaces:

Now check that iSCSI traffic has been enable of ethernet interfaces.  These interfaces can be up, but disabled on Ethernet traffic.  It is recommended to separate iSCSI traffic be separated from general TCP/IP traffic on Ethernet connections.  Thus it is encourage to disable iSCSI traffic on e0m if being used for RLM.  Also disable on other ports used for general TCP/IP traffic and enable on those Ethernet interfaces dedicated for iSCSI traffic.  Have host-side iSCSI initiators and storage-side iSCSI targets connected to a separate network is best practice.

Run the iscsi interface enable  command and speficy the interface on which iSCSI traffic will use.  Run the iscsi interface show command to see if iSCSI traffic has been enabled on the correct interface(s).

[4] Verify target portal groups:

Verify interfaces are assigned to valid iSCSI Target Portal Group (TPG).  By default DataONTAP assigns each iSCSI interface to its own default TPG to allow multiple iSCSI paths to each LUN.  To view available iSCSI TPGs and which iSCSI target interfaces are assigned to each TPG use iscsi tpgroup show.  Then to create a target portal group, run the iscsi tpgroup create .

[5] Create aggr/vols:


Finally create aggr/vols similarly to above FC SAN creation.