Firstly, if you’re planning
for doing a real-life head swap, these documents from support.netapp.com and kb.netapp.com
are worth reading:
Q: As a
training exercise, is it possible to simulate a headswap on the Data ONTAP
8.1.2/3 7-Mode Simulator?
A: My
conclusion is NO!
The reason? I
was unable to change the sys-id even after editing CFCARD and setting boot
loader options.
Note: If you change
the sys-id via the boot loader on the first ever boot of the simulator, it
works, but if you’ve already setup your sim, then the sys-id cannot be changed
(unless there’s another way …)
But … I present my
research for if it helps - perhaps someone reading knows how to do it J
My original
answer before reaching the conclusion above:
A: HA is out
of the question with the SIM, but simulating a single-controller head swap
might be possible - that is - we can simulate a situation where we change the
serial number, system ID (this is where I failed), and even motherboard serial
number.
And here’s how I
tried to do it!
Note: Here, the SIM
we’re using is called n701 and running 8.1.3 7-mode.
n701>
sysconfig
NetApp Release 8.1.3 7-Mode: Sat
Jun 8 08:11:51 PDT 2013
System ID: 4061490662 (n701)
System Serial Number: 4061490-66-2
(n701)
n701>
aggr status
Aggr State
aggr1 online
aggr0 online
n701>
vol status
Volume State
vol0 online
vol01 online
vol02 online
vol03 online
Performing a “Headswap”
on the Simulator
Step 1) Removing
Reservations
Logged in to the CLI as root (or equivalent), remove disk
reservations via the systemshell and then halt the SIM:
priv set advanced
useradmin diaguser unlock
useradmin diaguser password
systemshell
Login with user = diag
and the password set above
setenv PATH
"${PATH}:/usr/sbin"
echo $PATH
cd /sim/dev/,disks
ls
sudo rm ,reservations
exit
halt
Note: If you don’t
do this, then after you’ve changed serial and system ID, on trying to boot into
maintenance mode (5) you’ll get:
PANIC: Can’t find
device with WWN 0x1649826048. Remove ‘/sim/dev/,disks/,reservations’ and
restart …
Step 2) Editing
the CFCARD
Note: In my
ignorance, I thought this might get around the “System Id Mismatch” error, it
doesn’t!
With the SIM powered off, we first edit the CFCARD with
our new serial number, system ID, and motherboard serial number (the mobo
serial number isn’t really required to be changed, just doing it because we
can). In the working directory of the simulator, navigate to:
cfcard > env
And edit the env file with notepad (notepad++ even
better)
Image: The env file
in VM > cfcard > env
The default 7-mode SIM has these entries in the env file:
setenv
SYS_SERIAL_NUM 4061490-66-2
setenv bootarg.nvram.sysid
4061490662
setenv
MOBO_SERIAL_NUM 999999
We’ll change them to say:
setenv
SYS_SERIAL_NUM 1234567-89-0
setenv
bootarg.nvram.sysid 1234567890
setenv
MOBO_SERIAL_NUM 123456
Save the edited env file and close.
Note: It was hoped
that this might get around the following error after we set the system-id via
the boot loader:
WARNING: System id
mismatch. This usually occurs when replacing CF or NVRAM cards!
Unfortunately it
didn’t work.
Step 3) Changing environment
variables via the boot loader
Boot the SIM and at the:
Hit [Enter] to
boot immediately, or any other key for command prompt.
Press any key other then Enter!
At the boot loader (VLOADER>) prompt, run these
commands:
printenv
setenv MOBO_SERIAL_NUM 123456
setenv SYS_SERIAL_NUM 1234567-89-0
setenv bootarg.nvram.sysid 1234567890
printenv
boot
Step 4) Booting
into Maintenance Mode
At the:
* Press Ctrl-C
for Boot Menu *
Press Ctrl-C for Boot Menu
When you encounter the below error:
WARNING: System id mismatch. This usually occurs when
replacing CF or NVRAM cards!
Override system id?
And this is where I’ve hit a brick wall. It’s picking up
the system id from where I don’t know. Reading from an old
communities.netapp.com article there was mention of a ,sys-serial-num file (https://communities.netapp.com/message/37126),
trying to find it with the command below came up unsuccessful:
n701% find . -name
"sys*"
If you choose: y
It overrides your newly chosen system-id, so the system
still has its old system-id. You cannot re-assign disks to your “new”
controller system-id as you would in a head swap procedure.
If you choose: n
It halts with - ERROR: Please correct the problem and restart.
Comments
Post a Comment