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MSA Questions

Sean OB_1
Honored Contributor

MSA Questions

Ok, a couple of questions on the MSA systems.

1: How can you tell which controller is active?

2: When do you need Secure Path? Do you need it when an array has two controllers? When an array has a single controller but a host has two HBAs? Or only when dual hba, dual switch and dual controller?

3: What methods can you use to find the firmware of the controllers and the disks?

4: What happens if you have a single controller but it's in the "alternate" controller slot?

5: What happens if you have a single embedded switch but it's in the "alternate" slot?

6: What methods can you use to upgrade the firmware of disks and controllers?


TIA and points for all replies.

Sean


11 REPLIES
Uwe Zessin
Honored Contributor

Re: MSA Questions

1.) If you show me a picture of the controller's OCP - yes ;-)

Seriously, take a look at the two LED rows on the controller's front. The active LED is in the first row, second one from the right.

+---------------+
|O|O|O|O|O|O|A|O|
|O|O|O|O|O|O|O|O|
+---------------+

2.) First, a single host must only have one connection to a single controller - Two adapters might not work at all or cause errors. I have not found this rule explicitly spelled out in any documentation, but I have made it one of my configuration rules after having seen some error reports here on ITRC.

Next, for the second controller you need another fibre channel adapter. Don't try to access both controllers from the same adapter.

Now we have two controllers with two adapters. That makes two paths and on most operating systems you would need a multipath solution. For Windows you can use the (simple) basic MPIO or Secure Path (Workgroup Edition). For Linux the Qlogic failover driver or Secure Path. NetWare always need Secure Path. HP-UX is single-path only until the active/active firmware becomes available one day. OpenVMS and Tru64 Unix have multipathing embedded in the OS kernel.

3.) ACU (Array Configuration Utility) and ADU (Array Diagnostic Utility). You can get some controller information via the serial port and the command line interface (CLI>), but disk information is rather limited :-(

4.) I should work, because you can temporarily have such a situation during failure of Controller #1, but why would you want to do that in a single controller configuration?

Remember what you parents told you: don't do that!

5.) In a single controller configuration? The controller in slot 1 is not connected to this switch. You would need a Fibre Channel I/O module and route an external cable to that switch. That means that Port_0 would not be used, because it is reserved for the controller.

6.) I haven't had a chance to try it myself, but I have read here on ITRC that there is a firmware CD-ROM that can be used for upgrading the whole box.
.
Thayanidhi
Honored Contributor

Re: MSA Questions

Hi,
Are you preparing for MSA exam?

Answers If I am correct!

1: How can you tell which controller is active?

There is Active/Standby LED on the controller. ON=Active, OFF=Standby.

2: When do you need Secure Path? Do you need it when an array has two controllers? When an array has a single controller but a host has two HBAs? Or only when dual hba, dual switch and dual controller?

I believe required only when the host has more than one path to LUNs. Even if array is single controller the disk will be seen twice through each HBA(2hba) . In case dual controller/switch the standby controller will be active once the active is down. So the sencond hba need to continue the access to the MSA luns. If external switch used with single HBA with dual controller and switch is connecting both controllers, then also you need I think.

3: What methods can you use to find the firmware of the controllers and the disks?

For controller,
CLI (connected to serial), ACU, LCD front panel.

For disk (not sure)
CLI & ACU

4: What happens if you have a single controller but it's in the "alternate" controller slot?

I think it doesn't matter. The controler always knows whether there is standby or not. The current active will remian active. When the controller inserted in other slot, that will become standby controller. Also there is LED indicator whether the controller is in redundent mode or not.

5: What happens if you have a single embedded switch but it's in the "alternate" slot?
If no ISL is done, the switch on the slot with no controller or standby controller will not be communicating to MSA.

6: What methods can you use to upgrade the firmware of disks and controllers?

Depends on the OS type you are using.
scu on hp-ux
msa.exe from windows
msaflash from linux

I believe these utilities are availble in the CDs shipped with MSA.

Regds
TT




Attitude (not aptitude) determines altitude.
Sean OB_1
Honored Contributor

Re: MSA Questions

Yep, prepping for the MSA exam and these are the remaining items I'm not fully clear on.

For question #1 there is another method other than the #9 led. Does anyone know what it is?

We have to disparate answers for how to get the firmware revs on ctlr and disk. Can anyone from HP give a definitive answer?

TIA and all that.

Sean
Jefferson Humber
Honored Contributor

Re: MSA Questions

Sean,

Is this the HP0-803 exam ?

I think the other way to check for Active/Standby is to look at the OCP.

As for HDD F/W use the ADU/ACU or Insight Manager. For controller F/W use the ADU/ACU or CLI.

Jeff
I like a clean bowl & Never go with the zero
Uwe Zessin
Honored Contributor

Re: MSA Questions

The other way to determine the active controller is to look via CLI:

CLI> show this_controller
Controller:
...MSA1000(c) Compaq P563xxxxxxxxxx Software 4.24 Build 272 Hardware 7
...Controller Identifer: 100
...NODE_ID = 500805F3-xxxxxxxx
...SCSI_VERSION = SCSI-3
...Supported Redundancy Mode: Active/Standby
...Current Redundancy Mode: Active/Standby
...Current Role:............Active
...Device Port SCSI address 6

The installation is from december 2003, so please don't complain about old firmware. Controller #1 uses SCSI ID 6.

Whether the ACU shows this information, I don't know. All MSA1000 I have done in our shop were OpenVMS / Tru64 Unix related where I have used the CLI.
.
Sean OB_1
Honored Contributor

Re: MSA Questions

Jeff,

Yes, this is the 803 exam.
generic_1
Respected Contributor

Re: MSA Questions

I would use securepath EVEN if PVLINKS works for more than one path because of the active passive situation and say your switch dies but the MSA thinks the controller is still fine :). Why cant everyone have active active controllers :). Such a waste of bandwidth.
Sean OB_1
Honored Contributor

Re: MSA Questions

Here are the ones I wasn't sure about:

1: Which TWO can you DIRECTLY see which controller is active?

LED, OCP, ACU, ADU


2: Besides when the batteries are charging when is the array accelerator disabled?

3: What windows driver does secure path use?

4: If doing a das to san migration to a san with 20 volumes, what happens if the das has more than 12 volumes? Does the migration fail? Import 12? etc.

5: In Storage Virtual Replicator, if you expand a windows volume what needs to be done on the windows server to see the increased size?

6: Why would an array be slow when adding an expansion enclosure?

TIA.


Jefferson Humber
Honored Contributor

Re: MSA Questions

Sean,

1. LED, OCP

2. During an EXPAND operation

3. RAIDISK.SYS

4. Upto 12 DAS volumes will be migrated, no more.

5. Rescan in Disk Management

6. Array Accelerator disabled ?

Jeff
I like a clean bowl & Never go with the zero
Sean OB_1
Honored Contributor

Re: MSA Questions

Ok a couple of final questions before I head out to take the exam tonight.

1: Secure Path Manager. What needs to be done on a client to allow another machine to manage secure path?

2: What can Secure Path Manager do on a client? Load Balancing? Disable the HBA? etc.

Thanks everyone for all your help.

Sean
Jefferson Humber
Honored Contributor

Re: MSA Questions

Sean,

I think you can add the host in the Agent's list of authorised clients. You use the Secure Path Agent Config Utility to do this.

I think you also need to stop and start the agent service for it to become effective too.
I like a clean bowl & Never go with the zero