EMC – Silly things you can do with stress testing – Part 1

I have a whole swag of things I want to talk about with regards to EMC CLARiiONs and stress testing with SQLIO. But the posts are still forming and I want to be sure that what I put on the internet is accurate (a novel concept, I know) before I publish them. But what I can show you is the performance of our 4Gbps FC ports when running a particular read test on EFDs. In this instance you can see how, conceivably, the 8Gbps FC fabric becomes useful. At least for benchmarking.

Cisco – Generate ssh key with SAN-OS from the console

We had a situation a few weeks ago where we needed to stand up some HP / Cisco 9124e switches in a hurry. Unfortunately our data centre people initialized the switches and weren’t available to tell us what point they’d gotten to. We could see the switches in Fabric Manager and Device Manager, but for some reason we couldn’t ssh to the devices. And for some other reason we couldn’t generate a key to use with the switches. SAN-OS version is 3.3(4a). So here’s what we did to generate keys on the console (accessed via the HP Onboard Administrator on the blade chassis).

login as: admin



WARNING: This is a private system.  Do not attempt to login unless you are an

authorized user.  Any authorized or unauthorized access and use may be moni-

tored and can result in criminal or civil prosecution under applicable law.


Firmware Version: 3.21

Built: 11/15/2010 @ 09:59

OA Bay Number:  1

OA Role:       Active

admin@’s password:







HP BladeSystem Onboard Administrator

(C) Copyright 2006-2010 Hewlett-Packard Development Company, L.P.



Type ‘HELP’ to display a list of valid commands.

Type ‘HELP <command>’ to display detailed information about a specific command.

Type ‘HELP HELP’ to display more detailed information about the help system.



CHASSIS-OA1> connect interconnect 3


NOTICE: This pass-thru connection to the integrated I/O console

is provided for convenience and does not supply additional access

control.  For security reasons, use the password features of the

integrated switch.


Connecting to integrated switch 3 at 9600,N81…

Escape character is ‘<Ctrl>_’ (Control + Shift + Underscore)


Press [Enter] to display the switch console:


User Access Verification

switch1 login: admin


Cisco Storage Area Networking Operating System (SAN-OS) Software

TAC support: http://www.cisco.com/tac

Copyright (c) 2002-2009, Cisco Systems, Inc. All rights reserved.

The copyrights to certain works contained herein are owned by

other third parties and are used and distributed under license.

Some parts of this software may be covered under the GNU Public

License or the GNU Lesser General Public License. A copy of

each such license is available at

http://www.gnu.org/licenses/gpl.html and


switch1# sh ssh key


could not retrieve rsa key information


could not retrieve dsa key information


no ssh keys present. you will have to generate them


switch1# conf t

Enter configuration commands, one per line.  End with CNTL/Z.

switch1(config)# ssh key rsa 1024

generating rsa key(1024 bits)…..


generated rsa key

switch1(config)# exit

switch1# copy run start

And then it was all better.

Updated articles page

I’ve added another document to my articles page. This one covers the creation of port-channels between Cisco MDS 9513 switches. I was clueless about a lot of this until a friend from EMC took me through the steps. So I’ve created this document as a way to capture those steps for future reference. Hopefully you’ll find it of use.

Updated Articles Page

I’ve added another article to my articles page. This one covers the basics of initial configuration of various FC switches. It’s a little dated in places, but I found it a handy reference when I was deploying a lot of different vendors’ solutions in the field. You may find useful as well.

Cisco MDS 9XXX Basics – Part 4

Creating port-channels between Core – Edge … I had this blog post in my drafts section for a week, and then Scott Lowe – bless his cotton socks – beat me to it with a typically well-written post on ostensibly the same topic. So I’ll point you to his post, because it gets the idea across in a coherent fashion. I’ll make an effort, however, to get some more interesting switch config articles about before the Christmas break.

My SAN-OS skills are wack

I was making some port-channels between one of our MDS 9513 director switches and a 9124e edge and managed to add the interfaces to the wrong port-channel. Here’re the basic steps on the 9124e end that I took to rectify the issue. I’ve created a pdf file which, while inconvenient, solves the problems related to both my wordpress skills and the age of the theme I use. That is, a 4 page doc was going to look pretty ugly if I tried to insert it in-line. I apologise in advance for the inconvenience you will no doubt experience.

Cisco MDS 9XXX Basics – Part 3

Once you’ve setup the basic config of your switches, it’s important to backup your configs somewhere not on the switch. There’s nothing worse than not having a backup of your current configs and having to start from scratch. Especially if you’ve just done 20+ zones the hard way. Not that I would know what that feels like.

The first thing to do is create a backup job that copies the running config to the startup config, and then copies the startup config to a tftp host.

conf t
scheduler enable
scheduler job name backup_config
copy running-config startup-config
copy startup-config tftp://tftphost/backup/insertswitchname_cfg_$(TIMESTAMP).txt

Once you’ve done that, check your handiwork to make sure you’ve not made any embarassing typos.

show scheduler job name backup_config

Now you probably want to schedule your backup job to run at some kind of frequency.

conf t
scheduler schedule name nightly_6pm
time daily 18:00
job name backup_config

Check your schedule is good with this command:

show scheduler schedule

Happy? Good, me too. Because I’ve already backed up my configs. And so should you.

copy running-config startup-config

Oh wait, I created a job but put some garbage in it and didn’t realise until I saved everything. No problem, Cisco likes to use no for when you want to get rid of things. So to delete the job you just created …

conf t
no scheduler job name backup_config

As I’ve said before, my knowledge of Cisco SAN-OS and NX-OS commands is rudimentary at best, but I found these ones useful.

Cisco MDS 9XXX Basics – Part 2

Setting up ntp on your shiny, new Cisco MDS 9XXX switch is fairly simple. And important. Time man, it’s really important.

From a terminal session, issue the following commands:

conf t
ntp server prefer
ntp server

copy running-config startup-config

And that’s it …

Cisco MDS 9XXX Basics – Part 1

So we’ve finally started delivering on the project that I’ve been working on for the last 12 – 18 months. It’s fun to see my detailed designs turn into running infrastructure.

As part of this, I’ve been doing some configuration of some new Cisco 9513 and 9124e switches for our fabric. I have every intention of writing a downloadable article with some of the basic stuff, but I thought I’d do a few, smaller articles for my own reference more than anything else.

Now, most Cisco nerds will already know this stuff, but for someone like me who cut their teeth on Brocade Fabric OS, it’s a little different.

To connect to a 9124e (Cisco’s blade switch), I recommend using the HP OA’s serial connection.

Connect to the active OA via serial, login using your normal credentials and run

connect interconnect 3

This will connect you to the serial console of the first 9124e switch in the chassis. This assumes that you have other devices in bays 1 and 2, such as Cisco 3120s, or whatever.

If this is the first time you’ve connected to the switch, or if you’ve not configured it yet, you’ll get to a very useful first setup screen.

Press [Enter] to display the switch console:
  Enter the password for “admin”:
  Confirm the password for “admin”:

         —- Basic System Configuration Dialog —-

This setup utility will guide you through the basic configuration of
the system. Setup configures only enough connectivity for management
of the system.

Please register Cisco MDS 9000 Family devices promptly with your
supplier. Failure to register may affect response times for initial
service calls. MDS devices must be registered to receive entitled
support services.

Press Enter at anytime to skip a dialog. Use ctrl-c at anytime
to skip the remaining dialogs.

Would you like to enter the basic configuration dialog (yes/no): yes


  Create another login account (yes/no) [n]:

  Configure read-only SNMP community string (yes/no) [n]:

  Configure read-write SNMP community string (yes/no) [n]:

  Enter the switch name : FCswitch1

  Continue with Out-of-band (mgmt0) management configuration? (yes/no) [y]:

    Mgmt0 IPv4 address :

    Mgmt0 IPv4 netmask :

  Configure the default gateway? (yes/no) [y]:

    IPv4 address of the default gateway :

  Configure advanced IP options? (yes/no) [n]:

  Enable the ssh service? (yes/no) [y]:

    Type of ssh key you would like to generate (dsa/rsa) [rsa]:

    Number of rsa key bits <768-2048> [1024]:

  Enable the telnet service? (yes/no) [n]:

  Enable the http-server? (yes/no) [y]:

 Configure clock? (yes/no) [n]:

 Configure timezone? (yes/no) [n]:

 Configure summertime? (yes/no) [n]:

  Configure the ntp server? (yes/no) [n]:

  Configure default switchport interface state (shut/noshut) [shut]:

  Configure default switchport trunk mode (on/off/auto) [on]:

  Configure default switchport port mode F (yes/no) [n]:

  Configure default zone policy (permit/deny) [deny]:

  Enable full zoneset distribution? (yes/no) [n]:

  Configure default zone mode (basic/enhanced) [basic]:

The following configuration will be applied:
  password strength-check
  switchname FCswitch1
  interface mgmt0
    ip address
    no shutdown
  ip default-gateway
  ssh key rsa 1024 force
  feature ssh
  no feature telnet
  feature http-server
  system default switchport shutdown
  system default switchport trunk mode on
  no system default zone default-zone permit
  no system default zone distribute full
  no system default zone mode enhanced

Would you like to edit the configuration? (yes/no) [n]:

Use this configuration and save it? (yes/no) [y]:

At this point, the switch does a copy run start and reboots. For some reason we’ve been getting this error.

 Error: There was an error executing at least one of the commands
Please verify the following log for the command execution errors.
Disabling ssh: as its enabled right now:
 ssh: Cannot disable both telnet and SSH

I’ve been ignoring this error. So, too, has NX-OS. You’ll then see the following:

Would you like to save the running-config to startup-config? (yes/no) [n]: y

[########################################] 100%

The switch then reboots and you can monitor it for any errors. Once you’re satisfied with the config, use CTRL-SHIFT-_ and press d to disconnect from the 9124e terminal. The process is identical for the Cisco MDS 9513, except for the bit about it being a blade switch :)

ESXi 4.1 network weirdness – Part 3

So the only real update we’ve had on this ESXi problem is that it’s a bug. But I can’t give you a KB to reference, because, well, there isn’t one. And we’re not alone in feeling some pain about this, as Erik Zandboer noted on his blog. So I guess at this stage we’ll seriously reconsider if and how we use host profiles in the environment and wait for the new version of ESXi. It’s underwhelming but there you go.