SAN Interview Questions

1. What is LUN?
Ans:

•  lun is logical unit of number, which represent the physical unit of storage disk
• It is block level access
• Supporting operating system like Windows, Solaris, Linux, aix, and more
• Supporting protocols is FC and ISCSI

2. What kind of configuration FC or ISCSI? 

Ans:  Fc configuration (multi path)

3. What kind of Configuration is this? 

Ans: ISCSI (single filer)

4. What distinguishes FCP from iSCSI in a SAN environment?
Ans: 

FC	ISCSI
Block level access transfer through Fc switch fast and  flexible	Block level access Ethernet slower than Fc

5. Give an example of an attribute that needs to specified when creating a LUN

Ans:  lun size, volume or qtree name, igroup name, operating system type

6. Name three ways to create a LUN
Ans: 

• lun create in cmd
• Lun setup in cmd
• Filer view
• Snap drive in host side

7. TO DISPLAY LUN:
Ans: lun show [path] [/vol/vol_name/lun_name]

8. TO CHECK ALL LUN/IGROUP/FCP SETTINGS FOR CORRECTNESS:

Ans: lun config_check [lun path]

9. TO GET THE SERIAL NUMBER, TYPE AND MAPPING OF A LUN:
Ans: lun show -v

10. SHOW THE MAPPING OF A LUN:
Ans: lun show

11. TO SHOW SPLITTING LUN CLONES:
Ans: lun show -c

12. TO CREATE A LUN:
Ans:

Syntax : lun create –s(size) –t (os type) lun path

Example: lun create –s 100g –t windows /vol/vol_name/lun_name

13. TO DESTROY A LUN:

Ans: lun destroy [-f] lun_path [lun_path ...]

14. TO ENABLE THE LUN and TO DISABLE THE LUN:
Ans:

Enable lun : lun online [lun path]
Disable lun : lun offline[ lun path]

TO MAP THE LUN TO THE IGROUP and TO UNMAP A LUN:
Ans:

lun map: lun map /vol/vol1/lun1 igroup_name

lun un map: lun unmap /vol/vol1/lun1 igroup_name

15. TO FIND MAXIMUM SIZE OF A LUN FOR A VOLUME OR QTREE:
Ans:

lun maxsize /vol/vol3/

It shows:

With out snapshot reserve: 102.0m (106928640)
With snapshot reserve: no space
With complete snapshot reserve: no space

16. TO CHANGE THE SIZE OF A LUN:
Ans: lun resize /vol/vol3/lun3 +20m

17. TO CREATE A LUN CLONE:

Ans:

To create lun clone we must create one snapshot for lun contain volume

Snap create vol_name snap_name

lun clone create [new lun path] –b [parent lun path] snaphot name

18. TO SPLIT A LUN CLONE FROM A PARENT LUN:
Ans:

Once we created lun clone, new colne is attached to the parent lun, manually we need to split.
lun clone split start -d /vol/vol3/clone_lune

19. TO STOP A LUN CLONE SPLITTING PROCESS:
Ans:

lun clone split stop <lun_path>

20. TO SEE THE STATUS OF LUN CLONNING:
Ans:

lun clone split status

21. TO SEE THE COMMENT FOR A LUN:
Ans:

lun comment <lun path>

22. TO RENAME A LUN:
Ans:

lun move <old lun_path> <new_lun_path>

23. TO GET THE SERIAL NUMBER OF LUN:
Ans:

lun serial [lun path]
lun show -v

24. TO GET SERIAL NUMBER OF LUN IN HEX FORMAT:
Ans:

lun serial -x [lun path]

25. TO SET THE SERIAL NUMBER OF LUN:
Ans: 

lun set


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Netapp lun to Linux Server

Controller name : Bangalore1

Controller IP : 192.168.1.5

Aggregate name: aggr1

Vol name: vol1

Lun name: /vol/vol1/newlun

Igroup name: igroup_name

Fas3070> aggr create aggr1 20
Fas3070> aggr status
Fas3070> vol create vol1 aggr1 10g
Fas3070> vol status
Fas3070> ping <windows ip address>
Fas3070> lun create -s 7g -t linux /vol/vol1/newlun
Fas3070> lun show
Fas3070> igroup create -i -t linux igroup_name iqn.1993-08.com.linux:server
Fas3070> igroup status
Fas3070> lun map /vol/vol1/newlun igroup_name
Fas3070> lun show
Fas3070> iscsi start
Fas3070> iscsi status

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NetApp FC LUN Allocation on Windows Server - Hard Zoning

Purpose

The purpose of this document is to provide guidance and training on LUN assigning to a windows environment using NetApp technologies

Hardware Setup

NetApp FAS 960 (1 Nos), Brocade 200E switch (1 Nos), Windows 2003 Server with Emulex HBA installed

Connectivity Diagram

Prerequisites

Storage Configuration Prerequisites

· FCP License should be added

· FCP Service should be started

· Management IP should be configured for accessing the filer view

· Login credential should be available for accessing the filer view

· HTTPD options should be ON for accessing the filer view.

· Host HBA WWPNs should be available before creating Igroup.

1.2 Server Configuration Prerequisites

· Windows server with HBA installed

· HBAnyware utility (for Emulex HBAs) should be installed.

· NetApp DSM should be installed in case of multipathing (Not applicable in this scenario)

· Windows credentials for logging in

Brocade switch Configuration Prerequisites

· Cable connectivity to the storage should be proper

· Cable connectivity to the host should be proper

· Zoning should be proper

· Note down the Host and Storage WWPNs before creating zone.

· Switch credentials for loging in

PROCEDURE

FINDING WWPN OF HOST HBA

1. Login to the windows server, Open the HBAnyware utility,

2. Note down the WWPNs of the host HBAs

3. Open the Brocade Switch console
4. Select port admin in switch console window, then below console will open,
5. Select every port in the left side and click Devices details,

6. In which port you find the same server wwpn number means that port is connected in the server

7. In which port you find the Netapp filer wwpn number means that port is connected in the Filer,

8. Now port 3 and port 10 is connected in the switch, next we need to do Zoning for the two ports,

 9.  Click on Zone Admin tab, the below tab will open,

        Below we going to add one netapp  WWPN  and one server WWPN
         (10:00:00:00:c9:7c:d4:66 + 50:0a:09:80:83:60:f1:2e)

10. Select the zone tab on the new window,

11. Click on new zone and name the new zone(Zone_C_WINDOWS). 

12. After Created new zone name, select the newly created zone add the WWPNs of Host and Storage

Adding the new zone to the switch configuration.

13. Click on Zone config tab and select the newly created zone then add to the zone config.

14. Select the save Config and it prompt for YES or No, Select YES

15. Select Enable Config 

FINISHED 

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NetApp SnapDrive Features

SNAPDRIVE

• Snapdrive is an NetApp application and which is installed in UNIX and WINDOWS Servers.

• SnapDrive is an enterprise-class storage and data management solution that simplifies storage management and increases availability and reliability of application data.

• The key functionality includes error-free application storage provisioning, consistent data Snapshot copies, rapid application recovery, and the ability to easily manage data.

Features of Snapdrive 

1. Create LUNs, file systems, logical volumes, and disk groups 
2. Display information about storage entities 
3. Connect LUNs and storage entities to the host 
4. ReSize storage by increasing the size of the storage 
5. Disconnect LUN and storage entities’ mappings from the host 
6. Create Consistent Snapshot using SnapDrive.

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Lun creation using SnapDrive 6.4

Add caption

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iSCSI Lun Creation for Windows Host

LUN: Logical Unit Number 

In Netapp there is two ways of allocating lun to server

1. Fibre Chanel = through zoning
2. iSCSI = Through software initiator

Fibre Chanel:

• For allocating LUN from filler to server, we must do zoning with WWPN (world wide port number ).
• WWPN is nothing that "In windows for ethernet we called MAC Address" like here we call WWPN.
• WWPN is hardware port number of HBA(Host Bus Adapter)
• HBA is devices which help to connects the FC Cable to server and filer.

iSCSI

For allocating LUN from filler to server, we need to install initiator 2.x software.

In that software, we find IQN (iSCSI Qualified Name)

By using Iqn, we can find the Lun on the Host.

controller name : pri

controller IP : 192.168.1.5

Aggregate name: aggr1

Vol name: vol1

Lun name: /vol/vol1/newlun

igroup name: igroup_name

pri> aggr create aggr1 20
pri> aggr status
pri> vol create vol1 aggr1 10g
pri> vol status
pri> ping <windows ip address>
pri> lun create -s 7g -t windows /vol/vol1/newlun
pri> lun show
pri> igroup create -i -t windows igroup_name iqn.1991-05.com.microsoft:admcwindows10
pri> igroup status
pri> lun map /vol/vol1/newlun igroup_name
pri> lun show
pri> iscsi start
pri> iscsi status

Switch to windows
1. Open Microsoft iSCSI Initiator software , go to discovery tab and give the controller ip address for add iscsi

2. go to "Target" tab in the iscsi initiator software and click "Logon"

3. Right click the my computer --> manage select computer management

4. Now  new disk show in computer management and Right click the disk1 initialize the disk1
    If lun size is more than 2Tb we need to convert disk to GPT (Global partition table)

5. After initialize the disk, now make partition for new disk  by following steps

6. After click finish, now the status is formatting the disk

7. After formatted the disk, now its ready to use the disk in my computer

8. Now you access the full disk

CIFS Share Migration - Old filer to new filer Migration

Qtree SnapMirror (QSM)

1. Logical replication
2. Independent of the type of volume
3. Source volume and qtree are online/writable
4. Destination volume is online/writable

Requirements and Limitations for QSM

1. Supports Async mode only
2. Destination volume must have 5% extra space
3. Destination qtree cannot be /etc name
4. Cannot be initialized using a tape device
5. Does not support cascading of mirrors
6. Deep directory structure and large number of small files may impact performance

Migration task :

1. Here iam going  to copy one cifs shares from source filer to destination filler 
2. after migration user want to access his shares from destination filer
3. so we need to do some changes on source and destination
4. In destination side we need to configure cifs setup and others stuff

Other information:
share name : yogesh
username : yogesh

source> wrfile -a \etc\hosts 192.168.1.3 destination

source> ping 192.168.1.3
source> ping destination 
source> license add ******* => license no
source> options snapmirror.enable on
source> options snapmirror.access host=destination 
source> wrfile -a snapmirror.allow
192.168.1.3 # destination filer ip
destination # secondary filer name
Press CTRL-C to save and exit from the file
source> cifs shares
Name Mount Point Description ---- ----------- ----------- ETC$ /etc Remote Administration BUILTIN\Administrators / Full Control HOME /vol/vol0/home Default Share everyone / Full Control C$ / Remote Administration BUILTIN\Administrators / Full Control qtree /vol/vol1/qtree everyone / Full Control

Switch to Destination Filer for Pre-Check

1. check the filler panic error

# Commands

> check_netapp.pl Hardware -H <hostname|IP> -u  -o <temp|cool|power|nvram|disk>
> disk show -v

2. check rlm/sp is working properly

3. check all the disks are added properly

destination> aggr create aggr1 20
destination> aggr status
destination>  vol create vol1 aggr1 1g
destination> vol status
destination> wrfile -a \etc\hosts 192.168.1.2 source
destination> ping 192.168.1.2
destination>  ping source 
destination> cifs shares -add vol_qtree /vol/vol1/
destination> cifs shares # to check shares

destination > license add ******* => license no

destination> options snapmirror.enable on
destination> options snapmirror.access host=source
destination> wrfile -a snapmirror.allow
192.168.1.2 # source filer ip
source # source filer name
Press CTRL-C to exit and save the file
source> cifs shares
Name Mount Point Description ---- ----------- ----------- ETC$ /etc Remote Administration BUILTIN\Administrators / Full Control HOME /vol/vol0/home Default Share everyone / Full Control C$ / Remote Administration BUILTIN\Administrators / Full Control
vol1 /vol/vol1 everyone / Full Control


dst> vol restrict vol1 # please restrict qtree container volume.

CIFS Setup: we can setup cifs while ontap installation or after installation.

Blue color are some input for cifs setup.

This is after installation

destination > cifs setup This process will enable CIFS access to the filer from a Windows(R) system. Use "?" for help at any prompt and Ctrl-C to exit without committing changes. Your filer does not have WINS configured and is visible only to clients on the same subnet. Do you want to make the system visible via WINS? [n]:

A filer can be configured for multiprotocol access, or as an NTFS-only filer. Since multiple protocols are currently licensed on this filer, we recommend that you configure this filer as a multiprotocol filer (1) Multiprotocol filer (2) NTFS-only filer Selection (1-2)? [1]: 1
IFS requires local /etc/passwd and /etc/group files and default files will be created. The default passwd file contains entries for 'root', 'pcuser', and 'nobody'. Enter the password for the root user []:****** Retype the password:*******
The default name for this CIFS server is 'NETAPP'. Would you like to change this name? [n]:
ata ONTAP CIFS services support four styles of user authentication. Choose the one from the list below that best suits your situation. (1) Active Directory domain authentication (Active Directory domains only) (2) Windows NT 4 domain authentication (Windows NT or Active Directory domains) (3) Windows Workgroup authentication using the filer's local user accounts (4) /etc/passwd and/or NIS/LDAP authentication Selection (1-4)? [1]:1
In order to operate correctly within an Active Directory-based Windows domain, CIFS must use the DNS resolver service. That service is currently not configured on the filer. You must either configure DNS resolver services or choose a different authentication style. Do you want to configure the filer's DNS resolver service? [y]: What is the filer's DNS domain name? []: netapp.com # windows domain name What are the IPv4/IPv6 address(es) of your authoritative DNS name server(s)? : 192.168.1.4  # windows ip address Would you like to specify additional DNS name servers? [n]:n What is the name of the Active Directory domain? [netapp.com]:y
In Active Directory-based domains, it is essential that the filer's time match the domain's internal time so that the Kerberos-based authentication system works correctly. If the time difference between the filer and the domain controllers is more than 5 minutes, authentication will fail. Time services are currently not configured on this filer. Would you like to configure time services? [y]:n
In order to create an Active Directory machine account for the filer, you must supply the name and password of a Windows account with sufficient privileges to add computers to the netapp.COM domain. Enter the name of the Windows user [Administrator@netapp.COM]:administrator Password for administrator: CIFS - Logged in as administrator@netapp.COM. The user that you specified has permission to create the filer's machine account in several (2) containers. Please choose where you would like this account to be created. (1) CN=computers (2) OU=Domain Controllers (3) None of the above Selection (1-3)? [1]:1
IFS - Starting SMB protocol... Sun May 19 19:01:25 GMT [netapp:passwd.changed:info]: passwd for user 'root' changed. It is highly recommended that you create the local administrator account (NETAPP\administrator) for this filer. This account allows access to CIFS from Windows when domain controllers are not accessible. Do you want to create the NETAPP\administrator account? [y]:y Enter the new password for NETAPP\administrator: ******
Retype the password: ******
"NETAPP\administrator"
Welcome to the netapp.COM (CORP) Active Directory(R) domain. 

CIFS local server is running.

********************************************************I************

destination > ping windows_ip
destination> snapmirror initialize -S source:/vol/vol1/qtree destination:/vol/vol1/qtree
destination >
destination > snapmirror status -l vol1 

Snapmirror is on. 

Source: source:vol1 Destination: destination:vol1 

Status: Transferring 

Progress: 24 KB 

Compression Ratio: 4.5 : 1 

State: - Lag: - Mirror 

Timestamp: - Base Snapshot: - 

Current Transfer Type: Initialize 

Current Transfer Error: - 

Contents: - 

Last Transfer Type: Initialize

Last Transfer Size: 132 MB

Last Transfer Duration: 00:00:32 

Last Transfer From: source:vol1

destination > snapmirror update destination:/vol/vol1/qtree

destination >
destination > snapmirror status
Snapmirror is on.
Source                                        Destination                         State                    Lag             Status
source:/vol/vol1/qtree        destination:/vol/vol1/qtree       Snapmirrored           00:02:33           Idle

Note: Now both src and dst filer should have same size and files.

destination > snapmirror quiesce /vol/vol1/qtree        #its file-level so we should quiesce before break
destination > snapmirror break /vol/vol1/qtree           # check now dst volume should be read-write
destination > snapmirror migrate source:/vol/vol1/qtree destination:/vol/vol1/qtree

Note : As of now we copied the data from source filer to destination filer.
Now we need to load the qtree path in /etc/cifs_homedir_cfg.

destination > wrfile -a /etc/cifs_homedir.cfg /vol/vol1/qtree
destination > cifs homedir load -f
destination > cifs homedir showuser yogesh


Note : delete the old share and recreate the new cifs share for destination qtree.

source > cifs shares -delete qtree                                        # delete the old qtree share

destination> cifs shares -add qtree /vol/vol1/qtree              # create new share in new filer

*********************************************************************************

Then go windows user profile properties and change old filer name to new filer name or if you using
DFS software please update for the same






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