SAN (Storage area Networking) for System Administrators


I have started ( aka in 2009 as my own personal reference blog, and later sometime i have realized that my leanings might be helpful for other unixadmins if I manage my knowledge-base in more user friendly format. And the result is today's' You can connect me at -

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39 Responses

  1. Anil says:

    Good Article Ram, helps sys admins to understand the SAN env.

  2. admin says:

    @Anil, Thank you … Welcome to Gurkulindia

  3. nik says:

    good article, thanks!

  4. gkout says:

    Why would you need to explicitly define the LUNs you need to access in the solaris respective conf files, while you can do that on the fabric level by san switch zoning and EMC switch LUN presentation to specific hosts.

  5. Gurkulindia says:

    @gkout – in solaris 10 you wont require any local configuration, it can dynamically discover, build the device information and can make the LUNs visible to OS as local disks. But prior versions required this manual configuration to map the LUN devices into Solaris understandable Disk devices.

  6. Vinu says:

    hi guru ..Nice article

    . we have emc cx20 and we need to upgrade storage space . how we can add new luns in solaris 10 that alredy configured .

  7. sonu says:

    Good one

  8. Kombuter says:

    Hi , 

    please correct me if i am not mistaken by adding the devices this will create a single path to the disk or each disk will have two target path in the /dev directory also format command ? 

    please clearify . 

  9. Ramdev says:

    @ Kombuter – if you have two hba adapters to your server, which is connecting to storage array with two separate fiber cables . For each disk assigned to your server, you will see two device names. That will be visible in both /dev and format output. ….

    .for example if you assign two disks using two paths .. you will see them from one path as — c3t1d0 & c3t2d0 , from the other path it will be like c4t1d0 & c4t2d0. …

    by having multipath installed in your machine, you can configure ( like labeling & formatting operations) both the instances related to single disk using multipath device names e.g.

    emcpower1a for c3t1d0 & c4t1d0
    emcpower2a for c3t2d0 & c44t2d0

  10. Mushtaq says:


    as per my understanding of this article the target are the for N PORTs on the Storage device where we have WWPN. 

    as far as making persistent binding in the lpfc.conf file and configuring sd.conf file , i have a question .

    what does the target means since above diagrams doesnt define that ?  

    this article states “ the target number associated with the WWPN of the fiber array adapter is arbitrary” 

    to reformat my question as an SA where can i find this information that the LUN is located on so and so target ? 

    i think you got it i am confuse what and how to retrieve this target :) 

    thanks for the help in advance.

  11. Mushtaq says:

    to further confirm my above statement  please advise how we as SA will get these targets

    name=”sd” parent=”lpfc” target=40 lun=29;
    name=”sd” parent=”lpfc” target=41 lun=29;
    name=”sd” parent=”lpfc” target=42 lun=29;
    name=”sd” parent=”lpfc” target=43 lun=29;
    name=”sd” parent=”lpfc” target=44 lun=29;
    name=”sd” parent=”lpfc” target=45 lun=29;
    name=”sd” parent=”lpfc” target=46 lun=29;
    name=”sd” parent=”lpfc” target=47 lun=29;

    thanks again.

  12. Ramdev says:

    Hi Musthaq, for Solaris 10 and RHEL , we don’t need to do any of the information about targets, since it is all dynamic. what we just need is lun numbers to cross the whether the detected luns matching with the allocated luns.

    and for solaris 8 , normally storage team will tell you what is the target ID for the luns allocated for us.

  13. Mushtaq says:

    Thanks for the clarification ramdev , i was looking for 8/9 where we have to edit the sd.conf (disk) , st.conf (tape)

    one more confirmation i would require from you if possible.

    One lun can have multiple target and also one lun can have one target (both possible) ?

    lets suppose if LUN ID 40 have one target given by the SAN admin is target 23 , so what will be the syntax to write in sd.conf

    if one LUN ID 50 have 8 target given by the SAN admin target 10-18 how would that be . 

    finally are these both scenarios applicable in (talking about solaris 8/9) 

  14. Ramdev says:

    @Musthaq – Please find the answers below.

    your question : One lun can have multiple target and also one lun can have one target (both possible) ?

    Answer : Technically yes,one example is when you have one lun allocated from an array which connected using the dual path e.g. EMC clarion disk. And you have second lun from different array which has only one path e.g. a scsi based storage array. And you want to configure them both in your server

    And the simple way to understand this is : No.of targets you have for one lun = no.of.paths you have for the lun

    in first case – lun from EMC has dual path, connected using emulex hba. E.g. SAN team told to use you LUN ID 50 and the two targets from two paths are10 and 18
    sd.conf entries will be :
    name=”sd” class=”lpfc” target=10 lun=50;
    name=”sd” class=”lpfc” target=18 lun=50;

    for the second lun which is coming from scsi storage array with lun id 40 and target 23, you will make entries to the sd.conf as below
    name=”sd” class=”scsi” target=23 lun=40

    Hope this clarifies.

  15. Yogesh Raheja says:

    @Ram, very well explained. @Musthaq, One lun can have multiple target and also one lun can have one target (both possible) ?–> The ans is Yes but you wont see one lun one target configuration in bigger environments. Clients usually prefer one Lun many target configuration. Bzu one Bug has been indentfied in sol 8 or 9 I dont remember the version where in after performing storage migrations targets got mismatched in one to one configuration at that time EMC recommended one to many configuration in sd.conf to aviod any of the undetermined outage for SAN. So the issues are expected in one to one target configuration.

  16. Mushtaq says:

    Thanks a lot @Ram and also @Yogesh , i will try on that . thanks for the help.

  17. praveen says:


  18. shekar says:

    Ram /Yogesh

    How can i track and check the link between HBA and SWITCH because i’m getting packet transmission error occured in the hba driver .I was told by oralce that the latest patch to be applied .is there any way i can confirm to check the connectivity between hba and san switch ( p1,p2,p3) , I think beyond this point Solaris admin can’t access .Pl advise .

  19. Mushtaq says:

    shekar , we can find this information from the lputil in case of Emulex card , depend on the card and the solaris version , just a tip , for sure Ramdev/Yogesh can answer better :)

  20. Mushtaq says:

    Hi Ramdev/Yogesh/

    Can you please explain this file and how to get this information , i am confuse about target and lun numbers , thanks.

    name=”sd” parent=”lpfc” target=0 lun=0;
    name=”sd” parent=”lpfc” target=1 lun=0;
    name=”sd” parent=”lpfc” target=2 lun=0;
    name=”sd” parent=”lpfc” target=3 lun=0;
    name=”sd” parent=”lpfc” target=4 lun=0;
    name=”sd” parent=”lpfc” target=5 lun=0;
    name=”sd” parent=”lpfc” target=6 lun=0;
    name=”sd” parent=”lpfc” target=7 lun=0;
    name=”sd” parent=”lpfc” target=8 lun=0;
    name=”sd” parent=”lpfc” target=9 lun=0;
    name=”sd” parent=”lpfc” target=10 lun=0;
    name=”sd” parent=”lpfc” target=11 lun=0;
    name=”sd” parent=”lpfc” target=12 lun=0;
    name=”sd” parent=”lpfc” target=13 lun=0;
    name=”sd” parent=”lpfc” target=14 lun=0;
    name=”sd” parent=”lpfc” target=15 lun=0;
    name=”sd” parent=”lpfc” target=16 lun=0;
    name=”sd” parent=”lpfc” target=17 lun=0;
    name=”sd” parent=”lpfc” target=17 lun=1;
    name=”sd” parent=”lpfc” target=17 lun=2;
    name=”sd” parent=”lpfc” target=17 lun=3;

  21. Mushtaq says:

    sorry forgot to mention it is sd.conf file. Please advise , thanks in advance

  22. Ajay Sahu says:

    I want to know how to set account auto-logout after ideal period of an user in solaris.please revert friends as this is a audit issue in my envirnoment…

  23. Mushtaq says:

    From the sshd_config manpage

    Sets a timeout interval in seconds after which if no data has
    been received from the client, sshd will send a message through
    the encrypted channel to request a response from the client.
    The default is 0, indicating that these messages will not be
    sent to the client. This option applies to protocol version 2

    In your sshd config, add the line

    ClientAliveInterval 1200 #in seconds
    Protocol 2 #Doesn’t work on protocol 1

    Then restart sshd and you are off and running. 

  24. prajwla says:

    Thanks Ram….

  25. Mushtaq says:

    Hi Ramdev , 

    one new Question pop’s in my mind may be it can describe you what i am confuse at 

    What is a target in sd.conf file ? are we referring to Port Number on Fabric Ex : FA1B FA2A or  P1, P2 , P3 on SAN switch or Is it something else ? 

    anybody :? 

    thanks in advance.

  26. shekar says:

    Dynamic Reconfiguration of SAN disks from Solaris 10, without Solaris reconfiguration reboot:

    # cfgadm -al ( verification of FC conroller connections )
    # devfsadm -c disk -v (rescanning disks )
    # echo|format ( verifiy disks from OS)

    The above cmd is for Solaris .

    The same way how can i check in LinUX RHEL 4.x server ,if the new LUN is allocated to the host and how to ensure how many paths are avalaiable.

    what is equalent cmd in linux for the below .

    fcinof hba-port
    prtconf -vp | grep -i wwn
    luxadm -e port

  27. Mushtaq says:


    is it possible to have one PWWN from HBA connected to multiple Remote ports output is as below , can you elaborate how this is configured 

    mccah1sap029:/root> fcinfo remote-port -sl -p 10000000c6666712 |grep ‘Remote Port WWN’
    Remote Port WWN: 50001fe9000ec098
    Remote Port WWN: 50001fe9000ec09a
    Remote Port WWN: 50001fe9000ec09c
    Remote Port WWN: 50001fe9000ec09e

    • Ramdev says:

      @Musthaq. Yes it is possible.

      HBA@server–> Multiple Fibler conenction —> each conenction goes to one remote port of the SAN switch –> all switch ports target to single storage device

  28. Mushtaq says:

    ok , that said , N Port (host) –> F port -> N1 Port (fabric  FA1A) 
                                                                     N2 Port (fabric  FA2A) 

                            N Port (host) –> F port -> N1 Port (fabric  FA1B) 
                                                                      N2 Port (fabric  FA2B) 

    am i correct ?

  29. shiva says:

    EMC Fa1a target 11 555555555555551a
    EMC Fa1b target 12 555555555555551b
    EMC FA2a target 21 555555555555552a
    EMC Fa2b target 22 555555555555552b

    from where these numbers came

  30. Ganesh says:

    That’s really an amazing info you shared. It will be very useful if you explain for the linux SAN configuration step by step setup. Please let us know the link if its already there.

  31. MM says:

    It is a very good article, let me more clear of the SAN technology, thx~~~

  32. sushil prasad says:

    can you please tell me installation process/procedure of SAN in linux or you can recommended me to some website/video link .

  33. vijayababu says:

    How to re-setting the ilo passwd for T5120. we are for getting the ilo passwd. After connecting the Serial-MGMT port, what are all the steps to fallow.

  34. hashinmy says:

    can you doit for windows

  1. September 15, 2015

    […] SAN (Storage area Networking) for System Administrators […]

  2. September 17, 2015

    […] Read – SAN Guide for Beginners […]

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