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I have been using Shared Storage Pools phase 2 (SSP2) on the beta test a lot recently and it works well - I am very impressed. One key side effect of SSP2 is that it really makes Live Partition Mobility (LPM) very simple and safe.

 

But then I hit a problem that stumped me - nothing to do with the SSP2 technology - it was just that I in the Advanced Technical Support group have got rusty in setting up and using LPM.

 

The first problem that most people hit is that the source and target Power machines must have the same LMB size - the what?? Logical Memory Block - this is the memory chunk size that the Hypervisor allocates memory in for use to VIOS and Virtual Machines - I like to think of it in money terms as the smallest change size.  This is set in the HMC then ASMI menu Performance Setup tab - the default is very roughly something like one thousandth of your memory. If you have a wide variety of memory sizes on your machines you are going to have to decide a common size. By luck I had remembered that problem and we have ATS policy of LMB size of 128 MB and got that consistent on all machines as we have a planned power outage two months ago - it takes a cold machine boot to get this set.

 

Here is a remind on how to do set the LMB  ... on the HMC:

 

Log in with your Service Processor (FSP) user/password - that is the "admin" user - fingers crossed that you have remember the password when you initially setup the machine!

 

 

 Then take the Performance and Logical Memory Block menu

Change, if necessary, but don't forget the Shutdown the whole machine and restart it to make the new size active.

Because of the painful machine reboot, it is recommended to get this LMB Size correct during initial machine setup.

 

Once I created my SSP2 virtual machine and installed AIX 7 TL1, I tried Mobility to another machine in the SSP2 cluster and it failed for two reasons.

1) I tried the Live Partition Mobility (LPM) from the HMC - just a reminder of where to find this on the HMC see below - my Virtual Machine is called diamond5:


and then clicked through the various options and got the following during the LPM Validation check:

 

 
Also copied below so that hopefully Google might find it:

 HSCLA27C The operation to get the physical device location for adapter U8233.E8B.100271P-V2-C2 on the virtual I/O server partition diamondvios1-SSP has failed. The partition command is: migmgr -f get_adapter -t vscsi -s U8233.E8B.100271P-V2-C2 -d 0 The partition standard error is: child process returned error.

 

 Definitely, not the most helpful message I have seen and the HMC is generally pretty good.  If you run that migmgr command on the VIOS as the root user, then you will find it runs OK and returns an "80" on the screen. Hmmm!! Not helpfully either.  Next, I decided that there must be a problem with that VIOS resource (U8233.E8B.100271P-V2-C2) for my virtual machine that was blocking LPM. So I ran on the VIOS "diamondvios1-SSP" the command: lsmap -all | more  and looked for the C2 virtual adapter slot which connects the VIOS to the virtual machine.  Below is the relevant section of the output:

 

SVSA            Physloc                                      Client Partition ID
--------------- -------------------------------------------- ------------------
vhost4          U8233.E8B.100271P-V2-C2                      0x00000005

VTD                   vtopt0
Status                Available
LUN                   0x8200000000000000
Backing device        /var/vio/VMLibrary/AIX71_TL1_SP0
Physloc
Mirrored              N/A

VTD                   vtscsi0
Status                Available
LUN                   0x8100000000000000
Backing device        vdisk_diamond5a.b3f3a049c067ada140bc9f53f0a92b12
Physloc
Mirrored              N/A

Two things to note here:

A) The vdisk_diamond5a.b3f3a049c067ada140bc9f53f0a92b12 is the Shared Storage Pool Logical Unit (LU) i.e. the bizarre name that SSP uses for the virtual disk it has allocated to the virtual machine - cool it is working as expected.

B) The vtopt0 which is the VIOS virtual optical media device, which contains the ISO image /var/vio/VMLibrary/AIX71_TL1_SP0 which is the AIX7 TL1 DVD image from which I installed the virtual machine.

 

 

So on the VIOS, I removed the vtopt0 device with the padmin command: rmdev -dev vtopt0

 

 2) That fixed the above problem but then I immediately hit the next issue which, again, is caused by me getting rusty as I have not used LPM for a year or two - my colleague in ATS does the LPM demo's. Well that is my excuse :-) The LPM Validation failed this time as it could not find on the target machine the same virtual Ethernet port number on a VIOS. To point out the number I mean, see below:

 

 

 So I fixed this up on my target machine - I had just I got sloppy on my "crash and burn" demonstration machines and was using various port numbers.

 

The next Live Partition Mobility (LPM) worked perfectly and I am good to go for all future Shared Storage Pool virtual machines and can move the SSP based virtual machines to any of the four machines in the SSP cluster at will.

 

Thanks, Nigel Griffiths