Powerdown parameter for Solaris boxes.

I came across one unique parameter which I would like to share on our gurkulindia, specially for small business organisations where we dont have seperate power backups for DC.

Has anyone noticed while working on Solaris boxes if you will power down (init 5 or poweroff from LOM/ALOM/ILOM) the Solaris boxes, they wont come up automatically after physical power on (only LOM boots but No OS). Which is a serious concern if any power outage occur or any power unit failure occurs etc etc…

Ex: Suppose a power outage occurred in any DC and 100 Solaris boxes went down. Now after power restoration, you wont be able to see any Solaris Box up and running. Manual intervention is required and SA need to power on the boxes manually from LOM prompt. Practically this situation is highly unacceptable in any organisation and this is the default feature of Solaris.

After a long investigation and googling and PDF’s I safely landed on earth :-) and the landmark is below. There is a parameter on LOM/ALOM (for Sparc arch.) and ILOM (for intel arch.) which you wont find in help. The default value for that parameter is FALSE which wont allow your OS instance to boot up and hence it just stuck and wait for manual intervention at LOM level only.

I have tested the same in large scaled Solaris environment while performing hardware replacements & upgrades, when the value is FALSE the server stuck at LOM and OS wont come up, on the other hand if the value is changed to TRUE and power restored the Box comes up.

Below is the PARAMETER explanation with possible options:

sc_powerstatememory

ALOM runs as soon as power is applied to the host server, even if the server is powered off. When you first apply power to the host server, ALOM starts to run, but the server does not start up until you power it on.

The sc_powerstatememory variable allows you to specify the state of the host server as false (keep the host server off) or true (return the server to the state it was in when the power was removed). This is useful in the event of a power failure, or if you physically move the server to a different location.

For example, if the host server is running when power is lost and the sc_powerstatememory variable is set to false, the host server remains off when power is restored. If the sc_powerstatememory variable is set to true, the host server restarts when the power is restored.

The values for this variable are as follows.

true — “Remembers” the state of the host server when power was removed and returns the server to that state when power is reapplied.
 
false — Keeps the server off when power is applied

I think one change this value to TRUE on Solaris servers so that in case if any unintentional power outage occurs (when NO power backup is there) the server restoration time would be minimum.

Below is the procedure to check and set this parameter is below:

sc> showsc sc_powerstatememory
False

sc> setsc sc_powerstatememory true

sc> showsc sc_powerstatememory
True

Note: 1.) AIX and Linux are having this feature by default i.e both will boot up after power restoration by default.

              2.) Dont get confused with auto-boot, auto-boot is to restrict your OS to OK prompt.

Yogesh Raheja

Yogesh working as a Consultant in Unix Engineering by profession. And he has multiple years experience in Solaris, Linux , AIX and Veritas Administration. He has been certified for SCSA9, SCSA10, SCNA10, VXVM, VCS, ITILv3. He is very much passionate about sharing his knowledge with others. Specialties: Expertize in Unix/Solaris Server, Linux (RHEL), AIX, Veritas Volume Manager, ZFS, Liveupgrades, Storage Migrations, Cluster deployment (VCS and HACMP) and administration and upgrade on Banking, Telecom, IT Infrastructure, and Hosting Services.

9 Responses

  1. vasanth says:

    Nice to get more information regarding sun hardwares

  2. Yogesh Raheja says:

    Hi Vasanth, below link would be helpful to understand Sun Hardwares: http://gurkulindia.com/main/2012/09/oracle-server-hardware-reference-3d-view/

  3. Chris says:

    Hi there,

    I was wondering if after the power has been restored, the OS will boot automatically if the OBP varible auto-boot? is set to true.
    To see its value, from OPB (OK) just issue : printenv auto-boot?

    I think that these 2 variables are somehow related. I mean, if you have sc variable set to true, but OBP “auto-boot?” set to false, after your power restored, your server will only boot to OK. So, in order to have fully auto boot server you must have both variables set to true.

    Hope this helps other fellow admins.
    Chris

  4. Ramdev Ramdev says:

    Chris,  you are right.  
    Thanks for adding more information on this.

  5. Yogesh Raheja says:

    @Chris, thats very True, but the mentioned parameter is for HARDWARE power and not for OS booting. If your power goes down and this sc_powerstatememory is false your system hardware wont come up after power being restored i.e you need to manually PowerOn the box to get to PowerOn the hardware and henec to reach to Lom or OK prompt. Now the second thing comes which you stated auto-boot which should be TRUE in order to boot your OS. ;-). And ideally Auto-Boot should be set to true for any OS for quickest OS panic recovery. Thanks for this point. :-)

  6. Vinit garg says:

    Hi Yogesh,Suppose sc_powerstatememory set to True & in case of any hardware replacement activity we execute init 5 to poweroff the server but as this parameter is on then OS will again Up automatically??
    Tell me where I am wrong…

    • Ramdev Ramdev says:

      Vinit, init 5 just for power off and doesn’t take you to reboot cycle. The parmeter sc_powerstatememory will be effective when system gets power on again manually.

  7. Satheesh says:

    Very useful topic! We have checked in all our client servers’ consoles and all were configured with ‘sc_powerstatememory’ as ‘false’. Many thanks!
    But I would like to know if there is an alternative in case this variable is not available (like in RSC, Version 2.2).

    rsc> show sc_powerstatememory
    Unable to get value of variable ‘sc_powerstatememory’.
    rsc> showsc
    RSC Version: 2.2
    RSC Bootmon version: 2.0.0
    RSC Firmware version: 2.2.1

  1. September 17, 2015

    […] Read – Powerdown parameters […]

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