StorageAdmin

In this post, we will discuss naviseccli commands to create VNX LUN. Naviseccli is a software that you can install on Unix or Linux server and use that server for managing any VNX from a command-line interface.

You can use naviseccli for every management operation through the command line, including LUN creation, storage group creation, assigning LUNs to storage group, and many more.

Get the complete guide for Naviseccli commands.

List Naviseccli Commands To Create VNX LUN

Below are complete steps of LUN provisioning in EMC VNX.

Step 1. Connect to SPA or SPB of VNX.
Step 2. Create a LUN.
Step 3. Create a storage group.
Step 4. Assign the registered host to the storage group.
Step 5. Assign the LUNs to the storage group.

You can automatically generate naviseccli commands from here.

Step 1. Connect to SPA or SPB of VNX

You can connect to the SPA or SPB of the VNX storage using its IP address or FQDN. You must have the user name and password of the storage array. Make sure you use the correct scope, else the command will fail.

Scope	User Type
0	Global
1	Local
2	LDAP

naviseccli -h SP-IP -user username -password password -scope 0 -AddUserSecurity

AddUserSecurity option allows you to execute the next command without providing the username and password. Hence, the next commands will not have any user name and password.

Step 2. Create a LUN In naviseccli

Now you need to create a LUN using the below command. Below naviseccli command creates a thin LUN of 100GB from a storage pool. The LUN number is 10 which is also known as the ALU.

The -aa 1 assigns the LUN is either SPA or SPB. If you need to assign a LUN to a particular SP, then instead of -aa use -sp and give a value A or B.

naviseccli -h SP-IP lun -create -type Thin -cpacity 100 -sq gb -poolname poolname -aa 1 -l 10 -name LUN10

Step 3. Create a storage group.

The next, step is to create a storage group in VNX. A storage group contains LUNs and initiators. An initiator can only access LUN if they are part of the same storage group.

Below naviseccli commands creates a storage group “Production”.

naviseccli -h SP-IP storagegroup -create -gname Production

Step 4. Assign the initiator host to the storage group.

The next step is to assign an initiator to the storage group. You must first, complete the zoning between the initiator’s WWPN and VNX front end ports.

You can list out the connected host using below commands.

navicli -h SP-IP port -list -hba

Now, the below commands assign all initiators of server “ServerABC” to a VNX storage group “Production”.

naviseccli -h SP-IP storagegroup -connecthost -o -host ServerABC -gname Production

Step 5. Assign the LUNs to the storage group.

The final step is to assign LUNs to the storage group. Below naviseccli command assigns a LUN having a LUN number 10 to storage group Production.

Here, HLU stands for host LUN unit, which is used by a host to recognize LUNs in the host. You must provide a unique HLU number to a LUN within a storage group.

naviseccli -h SP-IP storagegroup -addhlu -gname Production -hlu 20 -alu 10

Conclusion

Finally, to list out the storage group information, you can use the below naviseccli command.

naviseccli -h ss1_spa storagegroup -list -gname Production

This blog explains What is SAN storage how it works. What are the various SAN components and how they connect to each other? This post is helpful for storage-admin to understand the basics of SAN architecture.

What is SAN Storage?

SAN stands for Storage Area Network. A SAN is a specialized high‐speed network of storage devices and FC switches connected to Host or Server via Fiber optic cables.

Host uses the storage from storage arrays as if its local to Host. As the data communication happens via fiber optics the data speed is high in comparison to NAS storage.

Components Of SAN Storage

SAN Components can be divided into 3 layers. Host, Fabric and Storage Layer. These three layers connect to each other and form a Storage Area Network Each layer has its own functions.

We will discuss their function in the coming section.

Below is a very simple architecture diagram of a Storage Area Network.

Basic architecture of SAN storage — The basic architecture of SAN storage

Host Layer

The host layer of SAN Storage has servers or hosts. Hosts are basically hardware having its own resources like CPU, Memory, Disk storage and an Operating system running on it.

Along with these, it has also dual HBA card which connects to the Fabric Layer of SAN Network.

What is SAN Fabric

The fabric consists of one or more FC SAN switches. SAN Switch provides connections between devices in SAN architecture. All Host and storage array connects to the same FC switch. Thus it acts as a mediator between Host and Storage.

Typical SAN network has two fabric for high redundancy. If one Fabric goes down then other fabric takes care of the data flows in the storage area network.

Storage Layer in Storage Area Network

In this layer, storage arrays are the important hardware where data resides in physical disks. Storage Array consist of physical disk. A logical grouping of the physical disk is called the RAID group. A storage admin assigns a RIAD type that protects the data in case of disk failure.

These RAID helps in data recovery whenever a disk failure occurs. There various types of RAID types. A storage admin has to use different types of RAID types as per requirement. The most common RAID types are RAID 5 and RAID 6.

Most of the storage arrays have Dual storage processors (SPs) which are the front end of the storage array. This SP has a front end IO module that has FC ports. These FC ports connect to SAN switch via FC cables.

Below is an architecture diagram of a typical Storage Area Network that has all hardware components with redundancy.

How SAN Storage Works?

When a host from a host layer wants to access a storage device, it sends out a block‐based access request for the storage device. SCSI commands are encapsulated into FC packets. Then the Host HBA transmits the FC request to the Storage layer via Fabric.

From the Fabric layer, SAN Switch then sends this request to the Array. In Storage Array, SP receives the request, processes it and then sends an acknowledgment back to the host through the same path.