Clearing a SAN lockdown state

Hah, are you really bragging that you know how to clear a lockdown at one of California’s finest hotels?

No… Just No, I think that would involve blackmailing the governator or some mild kidnapping both are way beyond my ability to pull off.

Is this something to do with restoring operation of a faulty biological SAN/pacemaker?

As much as I enjoyed biology in A level that would also be beyond my knowledge and this is a computer orientated blog.

I am talking about restoring operation of a Storage Area Network controller that has reached a software enforced lockdown state specifically the LSI/Netapp built IBM branded DS3524 SAN incorporates lockdown counters which track the number of power cycles that one/both controllers on this unit experiences and if a threshold is reached then a lockdown is enabled which prevents the unit in question from booting.

Is that a nasty tactic to sell service contracts?

I don’t think so, this behaviour is likely to protect your precious data from a flaky controller which is advantageous unless your SAN controllers are operating correctly but experience a series of temporary power fluctuations in that case once reliable power has been restored this lockdown would need to be cleared to enable operations.

This lockout is indicated by LU appearing on the twin 7-segment LED displays on the controller mounted status indicators to the rear of the SAN.

A word of warning, please ensure that the SAN controller is only in this state due to external factors and not a fault and as normal I take no responsibility for your actions.. if you kill you data it was your choice to try and clear this lockdown.

To perform this lockout reset you will need an IBM serial-console/din connector and a computer/remote console host equipped with a RS232/Serial/DB9 connector.

The IBM serial to Console cable is pictured below and should have been included with the SAN if not IBM may send you one

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This cable plugs into a female DIN port hidden under a black plastic cover at the rear of the SAN controllers.

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Install Putty on the computer connected to the SAN to be used as a terminal emulator then once the connection has been made set the connection to serial and then set the parameters as follows.

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Serial Line: This should be the COM port that your RS232 is port is listed as, this can be determined by the your system HW manager but in my case it should be COM 1.

Speed (Baud): any speed will do as the SAN controller uses adaptive baud rates but I use 19200.

Data bits: 8

Stop bits: 1

Parity: None

Flow Control: XON/XOFF

When you connect there may not be a message so press <CONTROL> and <BREAK> until correct speed detected, this will be indicated by intelligible onscreen text.
When prompted to press <S> for Service Menu press <ESC> instead.  This will take opens a shell prompt.

At this shell prompt you *may* be able to use these credentials as they seem to be generic with FW images (verified by these working on a replacement controller) if these dont work then contactyour IBM/LSI representative

User ID:    shellUsr
Password:    wy3oo&w4

The following commands need to be issued into this terminal in a specific order depending on which controller is in lockdown.

If controller A is in lockdown:

Run the following commands on both controllers –
lemClearLockdown
clearHardwareLockdown
psvClearSodRebootLoopCounter

Then unplug ctrl-A and run the following commands on ctrl-B:
loadDebug
cmgrSetAltToFailed
cmgrSetAltToOptimal

Then Hot-plug ctrl-A

This should sync setting across the controllers and clear the lockdown and you should be able to use your SAN again : )

Tasty Treats–reflowing a laptop motherboard

Reflowing, what on earth are you babbling about?? Spilling coffee on a laptop?

No that would be an article about how coffee is not to blame for my stupidity, I am taking about repairing a defective computer component.

Various computer components have a flaw related to ‘cold’/poor  solder joints that may crack/degrade after many heat/cool cycles, these joints provide electrical connections between electronic components and if these connections degrade there will likely be a failure or partial failure or the component containing the troublesome joint .

Contemporary computer systems generate a lot of heat while in operation and so cause cycles in operational temperature (in 10 years time when the low energy/heat ARM architecture has taken over as the dominant CPU architecture and GPUs are built on 8nm processes this may not be the case).

After a few years of use these degraded joints may show themselves as they did with my beloved Dell Latitude D820, a fantastic magnesium alloy dockable laptop with a beautiful keyboard and 2 hard disks, in this case my graphics card stopped outputting to the inbuilt LCD and produced scrambled graphics when connected to an external VGA display (no, I’m not a Dell salesman I am just trying to justify why I spent the time fixing this thing… apart from curiosity).

The technique detailed in this post can also be used to repair a XBOX 360 that has a bad case of red eye/Red ring of death

DISCLAIMER: this is a recount of my experience if you read this then get inspired to perform a similar operation and mess up then you may need to grow up and admit its your fault as I take no responsibility for your actions and decisions

Ok what is reflowing?

In short reflowing is bringing the temperature of the degraded solder connecting components to a point where it become liquid/flows and then disengaging the source of heat so that the solder can cool slowly and hopefully re-establish the joints.

So will I get a soldering Iron?

No, most components are BGA/surface mounted and although technically may be soldered using an iron you would waste too much time and need to be a master of soldering…. so I am going to suggest a much better approach, using an ambient heat source.

Ambient? what do you mean? mood heating?

I am suggesting putting your components in the oven or using a heatgun/hairdryer to melt the solder.

I tried the hairdryer method and although it worked well with a faulty XBOX 360 is was not so successful with my D820 which has a NVidia chip that has known heat problems which i supposed meant that a higher temperature than what a hairdryer can provide would be required to reliably reflow the D820.

Easy as Preheat, Prepare and Cook

The steps are as follows

  1. Preheat the Oven to 220C
  2. Remove all extraneous components e.g fans, plastics, keyboards, displays and disassemble the problem device
  3. Wrap all non-relevant portions of the component in aluminium foil
  4. Cook the component for 12 minutes or so
  5. Turn off the oven
  6. Turn on air extraction systems and open all windows/vents
  7. Open the oven door
  8. Leave the component to cool to room temperature before removing from the oven
  9. Reassemble the device (in my case the D820)
  10. Turn on and hope for the best

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Preheating the Oven

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A Powered-on faulty laptop

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Disassembling the Laptop

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Preparing the laptop by exposing only the troublesome components

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Powering a now fully working laptop

A month later my D820 is still working, even after burning it in for 2 weeks using a 3d stress test and no this is not my only computer its one of a bajillion but this is the one I wrote my undergrad and postgrad dissertations on and so I’m nostalgic about it and want it to live forever Smile