Tuesday
Jan282014

Awesome birthday present

And now my computer bag is no longer a spaghetti collection of miscellaneous cables and stuff. This is the Book Book Travel Journal from Twelve South.

So now I have the near complete mobile kit with:

  • USB to 30 pin
  • USB to lightning
  • USB to MicroUSB
  • USB to Ethernet
  • Several SD cards
  • USB SD card reader
  • DisplayPort to VGA
  • iPad 30pin to VGA
  • Power adaptor for the MacBook
  • Presenter Remote with laser pointer

The dangerous thing is that there’s a perfect slot on the side just made for the iPad Mini Retina that I am resisting buying.

Thursday
Jan232014

Can't format a VMFS-5 volume on an existing disk?

If you are cobbling together a home lab for ESXi, sometimes you’ll be reusing various disks that have been used in other computers with other operating systems. This can cause a problem for ESXi when you want to format a disk as a VMFS volume if there is an existing partition table and you want to format it using GPT for VMFS-5 and there is an existing MBR partition.

When you try to format the disk you’ll get an error like:

Error:A specified parameter was not correct.
Vim.Host.DiskPartitionInfo.spec
Error Stack
Call "HostStorageSystem.ComputeDiskPartitionInfo" for object "storageSystem" on ESXi "x.x.x.x" failed.

In my particular situation I am using a hosted Mac Mini so I can’t just grab the disk and wipe the partition table but it’s still possible from the command line. You’ll need to enable SSH and the ESXi Shell and use the partedUtil.

On my Mini I have a hard disk and an SSD which can be found under the /vmfs/devices/disks directory.

ls -lh /vmfs/devices/disks
total 1985717835
-rw-------    1 root     root        7.5G Jan 23 07:49 mpx.vmhba32:C0:T0:L0
-rw-------    1 root     root        4.0M Jan 23 07:49 mpx.vmhba32:C0:T0:L0:1
-rw-------    1 root     root      250.0M Jan 23 07:49 mpx.vmhba32:C0:T0:L0:5
-rw-------    1 root     root      250.0M Jan 23 07:49 mpx.vmhba32:C0:T0:L0:6
-rw-------    1 root     root      110.0M Jan 23 07:49 mpx.vmhba32:C0:T0:L0:7
-rw-------    1 root     root      286.0M Jan 23 07:49 mpx.vmhba32:C0:T0:L0:8
-rw-------    1 root     root      465.8G Jan 23 07:49 t10.ATA_____APPLE_HDD_HTS545050A7E362_____________________TEL51939JB8U1H
-rw-------    1 root     root      465.8G Jan 23 07:49 t10.ATA_____APPLE_HDD_HTS545050A7E362_____________________TEL51939JB8U1H:1
-rw-------    1 root     root      476.9G Jan 23 07:49 t10.ATA_____Samsung_SSD_840_PRO_Series______________S1AXNSADB12812X_____
-rw-------    1 root     root      476.9G Jan 23 07:49 t10.ATA_____Samsung_SSD_840_PRO_Series______________S1AXNSADB12812X_____:1
lrwxrwxrwx    1 root     root          20 Jan 23 07:49 vml.0000000000766d68626133323a303a30 -> mpx.vmhba32:C0:T0:L0
lrwxrwxrwx    1 root     root          22 Jan 23 07:49 vml.0000000000766d68626133323a303a30:1 -> mpx.vmhba32:C0:T0:L0:1
lrwxrwxrwx    1 root     root          22 Jan 23 07:49 vml.0000000000766d68626133323a303a30:5 -> mpx.vmhba32:C0:T0:L0:5
lrwxrwxrwx    1 root     root          22 Jan 23 07:49 vml.0000000000766d68626133323a303a30:6 -> mpx.vmhba32:C0:T0:L0:6
lrwxrwxrwx    1 root     root          22 Jan 23 07:49 vml.0000000000766d68626133323a303a30:7 -> mpx.vmhba32:C0:T0:L0:7
lrwxrwxrwx    1 root     root          22 Jan 23 07:49 vml.0000000000766d68626133323a303a30:8 -> mpx.vmhba32:C0:T0:L0:8
lrwxrwxrwx    1 root     root          72 Jan 23 07:49 vml.010000000020202020202054454c35313933394a42385531484150504c4520 -> t10.ATA_____APPLE_HDD_HTS545050A7E362_____________________TEL51939JB8U1H
lrwxrwxrwx    1 root     root          74 Jan 23 07:49 vml.010000000020202020202054454c35313933394a42385531484150504c4520:1 -> t10.ATA_____APPLE_HDD_HTS545050A7E362_____________________TEL51939JB8U1H:1
lrwxrwxrwx    1 root     root          72 Jan 23 07:49 vml.0100000000533141584e53414442313238313258202020202053616d73756e -> t10.ATA_____Samsung_SSD_840_PRO_Series______________S1AXNSADB12812X_____
lrwxrwxrwx    1 root     root          74 Jan 23 07:49 vml.0100000000533141584e53414442313238313258202020202053616d73756e:1 -> t10.ATA_____Samsung_SSD_840_PRO_Series______________S1AXNSADB12812X_____:1

So now I need to delete the existing partitions on the two internal drives with the following command:

/sbin/partedUtil delete /vmfs/devices/disks/t10.ATA_____APPLE_HDD_HTS545050A7E362_____________________TEL51939JB8U1H 1

Note the 1 at the end which identifies the partition to delete. If you have a disk with multiple partitions, you’ll need to delete each of them.

Once you’ve done that, you can go back into the VI-Client or the web interface and format the disk as a VMFS-5 volume.

Wednesday
Oct232013

Mavericks NFS alert

Just a quick note to help those that are upgrading to Mavericks and use NFS automounts.

By default, Mavericks will use NFS4 which uses a different security model so you may end up with what appears to be a regular mount, but it’s pretty much empty. Don’t worry the data hasn’t gone away or been deleted. It’s just that the user mapping doesn’t just cross check the local and remote UID of the user the same way, especially if you’re using PAM to grab UIDs from an LDAP directory.

I haven’t yet pieced together the best method to move to using NFS4 natively with my Solaris and OmnisOS boxes, but in the meantime, you just need to force the connection in NFS3. If you’re using automounts for user home directories, then add ver=3 to the automount entry and all will go back to normal.

Connecting via Command-K in the Finder with an NFS URL doesn’t seem to be affected at the moment.

Monday
Oct212013

Windows battery life & secondary impacts

Yet another article in the ongoing issue concerning the lackluster battery performance of Windows on portable computers, this time from Jeff Atwood of Codinghorror, with Anand Lal Shimpi of Anandtech weighing in on the situation.

What I find most interesting about this problem is not so much the problem posed to those using Windows based laptops (I feel for you), but rather the comparison with OS X on identical hardware. When you isolate the issue to identical use cases on identical hardware, you eliminate the screen, the networking, the keyboard backlighting, and so on. Finally you are left with the software and how it uses the hardware.

From a practical standpoint, we can discount the screen and the network and even the SSD since there is no “spindown” state and the power consumption is a straight line. Which leaves us the use of the CPU and GPU. It is clearly demonstrated that software optimizations can have a huge impact on efficiency and we’ve only seen the beginning from Apple. 10.9 Mavericks brings even more finely grained CPU and network scheduling.

Now my interest is in a different use case: Virtual Desktop Infrastructure. The existing and upcoming CPU optimizations implemented in OS X are potentially as useful in a shared CPU configuration like VDI as they are on a notebook computer.

This makes me wonder about the power efficiency of using Windows in a VDI installation. From the power consumption tests, it’s eating up more CPU to do the same job than does OS X, to the order of 50% more. Granted, in some tests, this results in slightly faster processing time, but only of the order of 15% in the best case scenarios.

On the one hand, that’s awful.

On the other hand, this type of system efficiency will become a much more pressing issue for Microsoft now that they are making their own hardware and need to be competitive with iPads and MacBooks on a work/watt basis. Which means that if Microsoft gets its act in gear, and can improve the overall efficiency of the CPU usage, we should be able to see even higher density workloads on the same server hardware. But it’s unlikely that this kind of thing will be retrofitted onto the existing Windows 7 systems and will only be available on future Windows 8 releases.

In the meantime, just use OS X on your portable computers if you want to get the most out of them, and hope that maybe some day we’ll see OS X as a VDI hosted option.

Although racking the new Mac Pros is going to require some innovative thinking…

Friday
Oct182013

It’s all a matter of perspective

I’m just catching up on my development RSS feeds and ran across yet another insightful technical article by Mike Ash. I’m finding this quite funny as I just gave a presentation at the Infralys (soon to be integrated in Ackacia!) hosted Rendezvous de la Virtualisation 2013 discussing the impact of SSD and flash storage arriving in the storage stack. Here are the slides for those interested.

In my presentation the coolest, most way out there SSD storage technology is the Diablo Memory Channel storage, where they put NAND chips onto cards that get attached to the RDIMM slots in your server. This is to ensure consistent (and very very very small) latency between the CPU and the storage. No jumping across the PCI bus and traversing various other components and protocols to get to storage, it’s right there accessible via the memory bus.

And here I have Mike explaining from the developer perspective “Why Registers Are Fast and RAM Is Slow”.

Always good to remind us that every part of the stack can be optimized and it’s a matter of perspective. Multi-millisecond latency fetching data from a physical object traversing multiple networks is forever for a modern CPU.

Thought experiment of the day: What if we configured our servers to behave like resource constrained devices, disabled swap and killed processes that stepped out of bounds? We’ve been taking the easy route throwing memory and hardware at problems that might have software optimization answers…

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