Blog For Storage Admin

What is FLOGI PLOGI and PRLI In SAN Switch

What is FLOGI PLOGI and PRLI In SAN Switch read this blog and you will get the answer. This blog has detail explanation of three device login process on SAN switch. Basically there are three device login process FLOGI, PLOGI and PRLI.

What is Device Login In SAN Switch ?

Device Login is a series of process which happens when a new node or devices is connected to a Fabric. Once Device Login Process Completes then a device can communicate with other devices in same fabric. Its Involves three steps FLOGI PLOGI and PRLI.

Components of Device Login In SAN Switch

Host – These are the server which are connected to Switch.
Array – These are the storage Array connected to Switch
SAN Switch – A SAN switch having FC Ports

Not only above three devices any other device which connects to SAN switch with FC protocol has to go through device login process..

What is FLOGI Process in SAN switch network

FLOGI Process happens when a new device is connected to switch or fabric for the first time. Once the device is power the device sends it first frame to the switch where it is connected. The first frame contains some information like WWPN and buffer to buffer credits (B2B credits).

The switch reads these information and then assign a 24 bit Unique ID address to device. This unique ID called as FCID. Switch uses this FCID to identify the end device connected to it in SAN network. Then the end device also confirms to the switch that it received FCID.

What is PLOGI SAN Switch Network.

Port initialization in PLOGI Process in SAN Switch

PLOGI Process has two port initialization and registration in Name Server. During port initialization information like port type and port speed are exchanged between end device or host and SAN switch. SAN switch use these information and negotiate with host. During negotiation SAN switch will come to know whether the end device is a server or a storage by referencing the port type.

What is Name Server In SAN Switch Network

During Name Server registration of PLOGI process the device register its information in Name server. This provides information to device about all other device which are registered in name server that it can communicate to.

Each fabric is SAN switch network maintains a name server. These name server contains the information of every devices connected to the SAN Fabric. Two device in SAN switch network can communicate only if both of them are Name server.

What is PRLI Process Login In SAN Switch

PRLI also stands for process Login. During this process actual communication happens between device connected to switch which are present in Name Server. In simple terms we can say that a during PRLI N_port communicates with another N_Port. In broad term a host communicates with storage array.

During PRLI process a host sends a PRLI request to storage array. If proper zoning and LUN masking is exists then storage array accept the PRLI request and start a communication between them.

Device Login Process SAN Switch With Diagram

Below is a diagram which explains step by step process of Device login in SAN switch network. Subscribe the blog for more such article.

Video Tutorial On Device Login Process SAN Switch

Watch the below videos tutorial from YouTube explaining the device login process in SAN switch. Subscribe the channel for more such videos.

Zoning In Brocade SAN Switch

Zoning In Brocade SAN Switch. We will discuss about zoning in brocade switch in details.Zoning is necessary to provide a secure path for SAN Host to access Storage Array. We will discuss how we can do zoning in brocade switch via command line.

Zoning in Brocade SAN Switch

Important Terms Brocade SAN Switch Zoning

Lets first some important terms on Brocade SAN switch zoning which is useful to understand the process
of zoning in brocade SAN switch.

What is WWPN in Brocade SAN Switch Zoning

WWPN stands for World Wide Port Name. Each port in SAN network has a unique WWPN. In SAN network port are identified by its WWPN. A WWPN is 64 bit address. Below is an example of WWPN
Ex : 10:xx:xx:xx:xx:xx:xx:xx

What is Alias Name In Brocade SAN Switch

Alias Name In Brocade SAN Switch are Human readable name of WWPN. As WWPN are 64 bit address and difficult to remember. SAN Switch admin provide a name for WWPN for easy reference.

What is Zone Brocade SAN Switch

Zone in Brocade SAN Switch are nothing but Group of alias member. These member are alias of Host WWPN and Storage Array WWPN.

Active Zone Configuration SAN Switch

Active Zone Configuration SAN Switch consists of Group of Zones in Active State. In a fabric only one Zone config can be in active state and the zones present inside it are effective zones.

What we need before Zoning Brocade SAN switch

Below are some of the information we need before we start ding zoning in Brocade switch

SSH Or GUI connectivity to Brocade SAN switch
Server Name For Zoning
Two WWPN of Server HBA Port- Connected to each Fabric
Ex : Host1: 10:xx:xx:xx:xx:xx:xx:xx
WWPN of Front End Storage Array Port Connected to Fabric
Ex: Array_Port1 : 50:xx:xx:xx:xx:xx:xx:xx:xx

Steps Of Zoning in Brocade SAN Switch

Once we have the above information. Below are the steps we need to perform. These are overall steps of zoning in brocade switch In next section we will see the CLI commands for zoning.

1.Check Connectivity of HBA Port To Fabric.
2.Create Alias Name For HBA Port WWPN and Storage Array Port WWPN.
3.Create a ZONE and add alias member in it.
4.Add the zone to active configuration zone
5.Save the active configuration zone
6.Enable active configuration zone

In some SAN network some additional feature are enabled for more security. Based on that the zoning may include more steps

CLI Command for Zoning in Brocade SAN Switch

CLI Command for Zoning in Brocade SAN Switch are executed by login to SSH or via Putty session on Switch. Below are the CLI commands of Brocade SAN switch zoning.

1.Check Connectivity of HBA Port To Fabric.
nodefind 10:xx:xx:xx:xx:xx:xx:xx
2.Create Alias Name For HBA Port WWPN and Storage Array Port WWPN.
alicreate “host1_hba1”,”10:xx:xx:xx:xx:xx:xx:xx”
3.Create a ZONE and add alias member in it.
zonecreate “zone1”, “host1_hba1; Array_Port1 ”
4.Add the zone to active configuration zone
First we need to find out which zone config in in active state using command.
cfgactvshow | more
cfgadd "activecfg1",“zone1”
5.Save the active configuration zone
cfgsave
6.Enable active configuration zone
cfgenable "activecfg1“

Today’s Question on Zoning In Brocade SAN Switch

Now a tricky question for you guys. Do research and let me know your answer in comment section.

What is the purpose of cfgsave command ?
What will happen if cfgsave command is not executed ?

Below is video on SAN switch zoning. Watch it Like it, Share It and subscribe the channel for more such videos.

What Is Zoning - SAN Switch Tutorial Part 2

This videos explains what is Zoning why we need zoning and what are the types zoning and difference between them In SAN Switch.

What Is Zoning - SAN Switch Tutorial Part 2

What is WWNN and WWPN ?

WWNN stands for World Wide Node Name and it a unique identification for each device or nodes connected in SAN network.

WWPN stands for World Wide Port Name. If any devices like or SAN storage array in SAN network has FC ports on it. Then it will have a unique identification which is WWPN.

Each device in a fiber channel Network will have a unique WWNN for each vendor and the Ports under it will have WWPN.

What Is fcalias, device-alias and alias?

fcalias and device-alias are CISCO SAN switch terminology. The WWPN are hard to remember hence an alias name is created for WWPN for easy reference. We can use fcalias within a single VSAN but devices alias are span across VSAN.

Similarly alias is Brocade SAN switch terminology. We can use alias for easy reference of WWPN. It is a 64bit address which is unique to each vendor.

Why We Need Zoning ?

There are various reason for zoning. The most important is security. In a SAN network many devices are connected to SAN switch. In order to make sure that the traffic flows between the intended device we create zoning. Zoning provides a secure path between an initiator and a storage array.

What Is Zoning ?

Zoning is binding or grouping of initiator port and target ports which ensures flow of traffic between a particular initiator and target. Zoning involves 3 to 4 steps which is performed in SAN Switch.

What are the types of Zoning ?
In simple terms there are two types of Zoning Hard Zoning and Soft Zoning.In most environment soft zoning is used. Hard zoning is very rare but as its more secure then soft zoning it is used for highly secure SAN network.

Difference between Hard Zoning and Soft Zoning ?

In Hard Zoning Domain ID and Port number of Switch are used to do zoning but in soft zoning WWPN of the Port or fcalies are used for zoning. Hard Zoning is highly secure then soft zoning.

In case of Hard Zoning If any physical changes in SAN network like cable swap between SAN switches happens then rezoning needs to be done. In case of Soft Zoning any physical changes like cable swap between SAN switches does not impact anything.

Check out the below videos for more details and subscribe to You Tube Channel for more such videos.

Basics Of SAN Switch - SAN Switch Tutorial Part 1

This videos explains a very basic concept of SAN switch. In later video we will discuss more on SAN switch.

What Is SAN Switch ?

SAN Switch is a hardware which have FC Ports. Host and Storage device are connected to it
It establish a communication link between host and storage device.

A Group of SAN switch is called as Fabric. Every SAN network has two fabric for redundancy. Popular Vendor Are Brocade and

Types Of Ports In SAN Network

F_Port: This is called as fabric port. This port is configured in SAN switch. This port connects to N_Port via fiber cable.

N_Port: This is called as node port which represents a target or host port. N_Port are connected to F port in SAN Network.

E_Port: This is called an expansion port. A port is which is designated an E_Port connects to the E_Port of another switch, to enlarge the switch fabric. This link is also called as Inter Switch Link (ISL).

G_Port: This is a generic port that can operate as either an E_Port or an F_Port.

Simple Architecture of SAN Network.

Below diagram show a simple connectivity of SAN switch in a Storage Area Network. This picture also shows the types of port in it.

Complex Architecture of SAN Network.

Below diagram show a complex connectivity and architecture of Storage Area Network.

Checkout out the below YouTube Video for explanation.

How To Recover Deleted Volume In Netapp Cluster Mode

How To Recover Deleted Volume In Netapp

In this video we will see how we can recover a deleted volume in NetApp cluster mode. This features is available in data ontap 8.3 and in later version. If you have deleted a volume and this feature is enabled then you can recover that volume within certain period of time.

How To Recover Deleted Volume In Netapp Cluster Mode

To see if the feature is enable or not execute the below command

vserver show -fields volume-delete-retention-hours -vserver vs1

The value under volume-delete-retention-hours indicates the retention period of the deleted volume in a vserver. If its none then the feature is not enabled. In order the enable the feature execute below command.

vserver modify -volume-delete-retention-hours 8 -vserver vs1

Above command will set the retention period of 8 hours of all volume under SVM vs1. Below command will show what are the volume which are in recovery queue or in other sense which are in pending delete state.

volume recovery-queue show -vserver vs1

Below command will recover the volume from recovery queue

volume recovery-queue recover -vserver vs1 -volume vv4_1033

After using the recover command, the following steps must still be performed to access the data.

Rename the volume running the volume rename command.
Set up a junction, if required, running the volume mount command.
Create mappings for LUNs in the volume, if required, run the lun map command.
Associate a snapshot policy, an export policy with the volume, if required, with the volume modify command.
Add new quota policy rules for the volume, if required, with the quota policy rule command.
Add a QOS policy for the volume, if required, run the volume modify command.

Video Tutorial For NetApp Cluster Mode

How To Send Email Using SMTPLIB Python Scripting

In this script we will see how we can send email using smtplib in python scripting. This script use gmail smtp server to send email hence we have used smtp server of gmail. You need to use your environment's smtp server to run this script.

Below is the entire script which we have written so far. Watch the video for full explanation and subscribe to the channel for more such video.

How To Send Email Using SMTPLIB Python Scripting

import paramiko,smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
p = paramiko.SSHClient()
cred = open("cred.csv","r")
for i in cred.readlines():
try:
line=i.strip()
ls =line.split(",")
print(ls)
p.set_missing_host_key_policy(paramiko.AutoAddPolicy())
p.connect("%s"%ls[0],port =22, username = "%s"%ls[1], password="%s"%ls[2])
stdin, stdout, stderr = p.exec_command("uname -a")
opt = stdout.readlines()
opt ="".join(opt)
print(opt)
temp=open("%s.txt"%ls[0],"w")
temp.write(opt)
temp.close()
msg= MIMEMultipart('alternative')
msg['Subject'] = 'Test Mail'
From = "fromemailaddress@gmail.com"
To = "toemailaddress@yahoo.co.in"
Cc = "ccemailaddress@yahoo.co.in"
text = "Info Collector"
data = open("%s.txt"%ls[0],"r").read()
part1 = MIMEText(text, 'plain')
part2 = MIMEText(data, 'plain')
msg.attach(part1)
msg.attach(part2)
s=smtplib.SMTP('smtp.gmail.com', 587)
s.ehlo()
s.starttls()
gmail_cred = open("gmail_cred.txt","r").read().split(",")
s.login(gmail_cred[0],gmail_cred[1])
s.sendmail(From, To ,msg.as_string())
s.quit()
except Exception as error:
print(error)
cred.close()

How Convert Python File To Binary File

In this script we will see how we can convert a python file to binary file or we can say .py to .exe file. Binary file can be executed in any system without installing the actual scripting language or any module. We will use a python module called pyinstaller to convert a .py file to .exe file.
One thing to note that you have to run the binary file in 64 bit operating system only if you have used a 64 bit operating system to convert .py file to .exe file.

How Convert Python File To Binary File

First you have to installed the module by executing below command in command prompt.

pip install pyinstaller

Then go to the directory where the .py file is located and the execute the below command to convert python file to binary file.

pyinstaller info_collector.py --onefile

Above command will bundled all dependencies and create a .exe file. The location of the .exe file will be displayed at bottom.

Watch the below video for details explanation. Also Subscribe to channel for more such video