Randomness (via

PEX Quick Take 2/14: Designing View with local SSD

The "View Reference Architecture" session presented an intriguing design option for ensuring View performance - using local SSD drives in blade servers for the linked clone/active desktop VM images. This is a solution primarily for "stateless" desktops (i.e. desktop images that are deleted without saving user configurations when the user logs out) and takes advantage of tiered storage features in View 5. The benefits of this solution include lower dependance on backend SAN storage to scale the solution up, thereby minimizing many of the challenges and bottlenecks the backend SAN can present. SAN storage is still a valuable component however for the server VMs, Gold desktop images, etc...

I think "stateless" desktops can also be used with persona management to save users preferences without having to have persistent desktops. We may have to lab this.

The Cisco B230 blades can be configured with 128GB or 200GB SSDs. Worth looking at if the requirements fit.


VMware PEX - Day One general session

Scott Lowe has a detailed summary of this morning's General Session at VMware PEX featuring VMware CEO Paul Maritz and CTO Steve Herrod.

One quick observation - seemingly every third slide featured an iPad and there was much talk of post-PC. Interesting times ahead for enterprise IT for sure.


Quicktip: Increasing port-profile max-ports on Nexus 1000v

A common limitation I see customers regularly hitting on the 1000v is the default “max-ports” value of 32 on a port-profile. Once a 33rd virtual machine is assigned a certain port-profile it gives an error and doesn’t allow it.

Fortunately the fix is easy. Just up the value within the port profile:

port-profile MY-PROFILE
    vmware max-ports 64

Note: The range can go as high as 1024. Max-ports configuration only applies to non-uplink ports.


Cisco goes 40 and 100 Gigabit Ethernet

Last week Cisco announced new 40 and 100 Gigabit Ethernet modules for the Catalyst 6500 and Nexus 7000. I’m guessing that next up will be Nexus 5000s with 40GE uplink ports[1].

Nexus 7000

The Nexus 7000 now has a 6 port 40G M2 module (datasheet) and a 2 port 100G M2 module (datasheet) - both non-blocking, and both capable of layer 3 in addition to layer 2. Both modules are supported in all Cisco Nexus 7000 Series chassis and compatible with Fabric–1 or Fabric–2 fabric modules.

The only available optics for the 100G module are LR4 modules that run 10km over G.652 single-mode-fiber.

The 40G module can reach up to 150m (30m or 100m seem more likely unless the fiber runs are carefully engineered) over 50 micron multi-mode-fiber with available SR4 optics.

There are some interesting “Quad Small Form-Factor Pluggable Plus” (QSFP+) modules available for 40G, including 1, 3, and 5 meter copper cables (similar to the 10GE twinax cables), and a 40G QSFP+ to Four 10G SFP+ breakout cable. Other than the SR4 optics these other QSFP+ modules currently only seem to be compatible with the Nexus 3064 switch that has four fixed QSFP+ uplink ports.

Catalyst 6500

The 6500 is getting a 4 port (2:1 oversubscribed[2]) 40GE module (datasheet). Supported 40GE optics are an SR4 that works at 100m over OM3 multi-mode fiber, and an LR4 that will reach 10km over single-mode fiber. A 40GE port slot can also accept a FourX adapter that will then provide four 10GE SFP+ ports in a slot. A single module can have a mixture of 40GE and 10GE ports.

The 6500 40GE module (unsurprisingly) is only compatible with the new Supervisor 2Ts.

  1. I haven’t heard anything yet though.  ↩

  2. Two ports can be set into “performance” mode, disabling the other two ports, for a non-blocking configuration.  ↩


OS X command line tricks for SSH and serial console connections

One of the things I love about Mac OS X is having the UNIX-like command line available via Terminal. I tend to just use Terminal for ssh and console access to routers and switches and the like. I do however like to have my output automatically logged to a text file, so I created TextExpander snippets to pipe output to the "tee" command with automatically set a date-stampted filename.

For SSH the looks like:

 ssh user@ | tee /Users/klaus/ssh_logs/%Y-%m-%d-%H%M%S-ssh.txt

For console via USB to serial this becomes:

 screen /dev/tty.KeySerial1 | tee /Users/klaus/ssh_logs/%Y-%m-%d-%H%M%S-console.txt

Works pretty well so far