Takeaways from Keynote of VmWorld 2015

Happened to listen to the KeyNote of Pat Gelsinger in Vmworld 2015 . Very valid and interesting talk.

Summarizing the key takeaways from his KeyNote 2015 and some key points i found interesting.


=>  MOBILE-CLOUD
=> Asymmetry in the business -> Incumbents Vs Upstarts
=> Innovate like a startup and Deliver like an Enterprise
=> Unified HYBRID CLOUD
=> Protecting People, Applications , Data a.ka. Security
=> Built-In vs Bolted On aproaches
=> Application -> Big Data -> Analytics (Proactive technologies)
=> Automate Everything. Collect and Keep it forever
=> Half of the Tech-100 S&P will disappear
=> Taking Risks == Lowest Risk

Very profound and thought-provoking statements.

Different Type of I/Os generated by IO Tools

Block I/O:
=========
- Initiated through native device files /dev/sd*.
- I/O transfers in fixed-size blocks
- write I/O exchange consists of transferring data blocks from the address space of the calling process to the kernel’s buffer cache, and then to the disk device.
- a read I/O exchange consists of transferring data blocks from the disk device to the kernel’s buffer cache, and then to the address space of the calling process.
- type of I/O is primarily used to support file systems where frequently accessed data can remain resident in kernel buffers, eliminating the need to repeatedly access the disk device and where I/O can be queued in the buffers until a threshold is reached before a disk device transaction is performed, optimizing efficiency.

RAW I/O :
=========
- initiated through special raw device files.
- I/O transfers in fixed-sized blocks.
- bypasses the kernel’s buffer cache so data is exchanged directly to and from the address space of the calling process, reducing the amount of required system bandwidth and improving I/O throughput
- type of I/O is primarily used to support database operations where the size of transactions tends to be small and the performance throughput is more critical.

Scatter-Gather I/O or Character I/O:
===========================
- initiated through special sg devices files /dev/sg* (or pass through driver).
-supports I/O of variable-sized blocks.
- provides direct access (i.e. pass-through) to SCSI devices, allowing the calling process to send direct SCSI commands to various devices including hard disks, CD-ROMs, and CD burners and to receive direct responses to the those commands.
- type of I/O is primarily used to perform low-level operations on SCSI devices that are not possible with the sd, st device drivers.

ASYNCHRONOUS I/O (or AIO):
========================= ====
- initated through special raw device files /dev/raw* using the LIBAIO library
- supports I/O of fixed-size blocks.
- Once the calling process issues the I/O request and the request is queued to the destination device, it immediately regains control of execution, allowing it to issue additional subsequent requests. The completion of an I/O request can be signaled to the calling process or the calling process can periodically poll the status of its I/O request.
- type of I/O is primarily used for high speed applications such as computation-intensive processes

Host Based Migration Methods

Host-Based Backup and Restore Migration:(Disrutptive)

Here we use an utility to copy an existing disk/lun to a newly provisioned disk/lun. This requires additional storage of equal or greater size than the original lun. The migration will consume CPU cycles on the host.

The application will be offline for the copy duration and will be reconfigured once the copy is done.

1. Make the target LUN available to the host
2. Quiesce/stop the host application
3. Backup the source LUN to the target LUN
4. Reconfigure/Restart the application.

Host based LVM mirror:(Non-Disruptive)

This method also requires additional storage at least the size of the source LUN.There is no disruption to the application. But, host CPU cycles are consumed.

Steps

1. Make the target LUN available to the host
2. Add the target LUN as mirror to the LVM volume containing the source LUN.
3. Break the mirror after the destination is in sync.

Virtual Desktop Infrastructure

I was looking at getting into a peek at what is a Virtual Desktop infrastructure and its use cases / applications.

Have a look at these videos to get a preview of what it means

Part 1:

http://www.youtube.com/watch?v=zGDwD9afZ94&feature=PlayList&p=00122D416E40AD94&index=11

Part 2

http://www.youtube.com/watch?v=IRNR0KEOBQ4&feature=related

Understanding the FCOE Technology

I have recently started following the blogosphere re: FCOE technology and here is a handy references of a few things i found interesting.

Nigel Poulton http://blogs.rupturedmonkey.com/.

YouTube References

Intro to FCoE w/ EMC http://www.youtube.com/watch?v=EZWaOda8mVY – basic 101 of the technology

Deploying FCoE w/ EMC http://www.youtube.com/watch?v=y6IHMXEGRXs – the new equipment that you’ll need including cables, adapters and switches

FCoE Ecosystem http://www.youtube.com/watch?v=ExxilbDvZ1g

FCoE discussions w/ Kash Sheik of Cisco on the Storage (http://www.youtube.com/watch?v=GTz9S0cSdNo) and Network (http://www.youtube.com/watch?v=r1mI-eB8-iE) implications of fcoe

Presentations
EMC World 2009 presentation: Fibre Channel over Ethernet (FCoE), iSCSI and the Converged Data Center – http://www.slideshare.net/stuminiman/fibre-channel-over-ethernet-fcoe-iscsi-and-the-converged-data-center
Innovation Network Lecture – Journey Towards the Converged Data Center (archived webinar) https://community.emc.com/docs/DOC-4398

Papers
Introduction to Fibre Channel over Ethernet (FCoE) http://www.emc.com/collateral/hardware/white-papers/h5916-intro-to-fcoe-wp.pdf (Updated Nov ‘09)
Fibre Channel over Ethernet Techbook [from EMC E-Lab] http://www.emc.com/collateral/hardware/technical-documentation/h6290-fibre-channel-over-ethernet-techbook.pdf

Types of Virtualization / Types of Hypervisors

This blog post will explain the types of server virtualization that is prevalent today and the various types of hypervisors ( the virtualization layer) in scope today.

Types of Virtualization:
1) FULL VIRTUALIZATION
This is also known as native virtualization. This method consists of a virtualization layer or a hypervisor that intermediates between the guest operating system and the underlying hardware.
For Example: VMWARE ESX SERVER .
This runs on top of a native hardware and intermedites the guest OS and the hardware. The hypervisor monitors the instructions executed by the guest OS and traps certain privileged instructions that directly meddle with the underlying hardware since it is shared across the guest OSes. The guest OS can run unmodified in the case of Full / Native Virtualization.

2) PARA VIRTUALIZATION
This type of virtualization still consists of a virtualization layer called the hypervisor to co-ordinate access to the shared hardware by multiple guest Operating Systems, but the guest OSes are themselved tuned to be virtualization aware so that there is no need of any trapping and hence close to performance of a OS running on top of a real hardware.
Ex: XenServer
The guest OS need to be modified for the hypervisor on which it will run.

Type of Hypervisors:
"Hypervisor" - The "visor" who manages multiple "Super" visors. In early days , each Operating system itself was termed as the "Super"visor since it manages the hardware and software resources. Now, since the hypervisor abstracts or manages the resources across multiple guest Oses or Supervisors , it is called as "Hypervisor".

1) Type 1 Hypervisor: Hypervisors that run directly on top of physical hardware are called as Type 1 or bare-metal hypervisors.
Ex: ESX Server , Citrix XenServer, Oracle VM, Microsoft Hyper-V
The guest OSes run at the second-level on top of the Type 1 hypervisors.
Hardware -> Type 1 Hypervisor -> Guest OS

2) Type 2 Hypervisor: Hypervisors that run within an Operating System Environment are called as Type 2 Hypersiors or Hosted Hypervisors.
Ex: Vmware Workstation, Microsoft Virtual PC
The guest Oses run at the third-level on top of the Type 2 hypervisors.
Hardware -> Base-OS -> Type-2 Hypervisor -> Guest OS.

Fabric Discovery and Initialization

One of the most frequent questions that people ask is how does the FibreChannel initiators intialize and discover the targets and what happens before the initiator and the target start
communicating. Let me try to explain the same in a sequence of steps.

When a Node initializes in a Fibre Channel environment, the potential actions include the following
1. Link Speed Negotiation
2. Link Initialization and Determination of the port's operation mode(N_Port)
3. Fabric Login (FLOGI) with the Fabric Login Server ( 0xFF FF FE ). FLOGI is an ELS (Extended Link Service provided by FC)
4. Port Login (PLOGI) with the Name Server or Directory Server ( 0xFF FF FC) .This is infact the mechanism of the N_Port to register information with the Name Server.
5. Registering to receive State Change Notifications (SCR). This is typically done with the Fabric Controller ( 0X FF FF FD)
6. Retrieving Information from the Name Server. This is done using Name Server queries. This is the mechanism for address discovery of SCSI Storage Devices
(Ex: Some of the commonly used queries to get objects from the directory server are GA_NXT - Get al Next , GID_FT - Get FCID)
7. Once the address are retrieved, the initiator port does a logging in (PLOGI) with other node ports. Typically the SCSI-FCP initiators initiate the login and the targets wait for the login to occur.
8. The initiators then perform a Process Login (PRLI) to negotiate other information before they start sending commands to the target.
9. The initiator may then perform a TUR (Test Unit Ready) to check the readiness of the target unit. It will then do a REPORT LUNS to discover the LUNS supported by the target and then a SCSI Inquiry to obtain information about each LUN.

This sums up the typical initialization sequence and the stuff that happens.......

Hook up an analyzer between a Server and a Fabric Switch and capture the trace....

If you see something different from the sequence described above...let me know..:)-