Thursday, 27 December 2012

Starting a career in storage domain. . .

Starting a career in storage domain can be very challenging and interesting. However, I believe that background in systems administration with extensive use of CLI can be very helpful. Being a storage admin you constantly need to work with the array software and CLI (for the core). Generally most array software’s are very user friendly and provides multiple wizards to achieve most common tasks. However, you soon find out that you need to know a lot about other things too. Such as you have to understand the Storage area network and work with a network administrator to configure zoning on SAN switches. OS on most of the arrays are based on Linux. Therefore Linux working knowledge is also required as I mentioned earlier systems administration experience comes handy. Last but not least whenever you are configuring arrays and provisioning storage to hosts you are doing so for some particular server or application. Most of the times you are allocating storage for email mailboxes and virtual machines. To perform such activities along with their respective administrators you too needs to understand the basis of email server and virtual desktop / application technology. Finally if you can read a lot and practice on your own, you definitely won’t face many problems.

Monday, 24 December 2012

EMCIE - EMC Implementation Engineer

 I recently got my EMCIE certificate. Here I like to share that EMC VNX Unified system is very powerful storage and ideal for mid to large size infrastructures. It supports Flash and SAS for performance and NL-SAS for capacity requirements. Besides many new features (FAST Cache, Improved UI) , one VNX feature which I like most is that it has DAE / BUS  numberings instead of LED lights, this helps tremendously while expanding storage enclosures.
To sit for EMCIE exam you have to prepare for both VNX block and File level. It will be very exciting to learn VNX as EMC provide lots of guides and even simulators to help understand its working. For Storage Administrators, I can recommend EMCSA exam, [EMC Storage Administrator].
You will also get a badge pin along with electronic certificate after passing the exam. One more thing the exam course will be revised after 31st December 2012, so plan it accordingly.

Friday, 30 November 2012

Adding Storage

Whenever adding disk array enclosures, make sure to read the documentation and instructions completely. Daisy chaining DAEs can be very fascinating task but it also required proper planning for the harnessing for the cables. First count the required numbers of cables and verify the connectors (SFP, HSSDC, HSSDC2 etc). Draw the diagram on a piece of paper to understand the DAEs’ locations and then measure the cable length for expansion.

Monday, 22 October 2012

Wednesday, 4 July 2012


ILM or information lifecycle management strategy models information's accessibility with respect to its value to the business. Mostly all the unstructured (80%) enterprise data lose its value over time.
With ILM, data administrators can move such data to relatively medium end storage tier in a multi-tier architecture. This can enable organizations to appropriately manage data based on its value and archive / dispose it according to enterprise requirements.

Thursday, 28 June 2012

Calculating Average Latency (ms)

Ave. Latency = (0.5) x(60)x 1/RPM


Disk RPM =15000 or 15K


Ave. Latency    = (0.5) x (60) x 1/15000

                        = 0.002


Ave. Latency = 2ms


10K RPM         ->         3ms

7200 RPM       ->         4.16ms

5400 RPM       ->         5.55


Wednesday, 27 June 2012

Replacing hot swappable disk:

Hot swap-able disks, I/O cards, SPS as well as SPEs are are the most fascinating functionality of modern day enterprise storages. It enable organizations to keep up with their RPO and enjoy the 24/7 availability of data. Almost all arrays with RAID configuration can have hot swap-able capabilities.
Nowadays SAN, NAS and VTL have spare disks, which can automatically replace failed disk. Number of spares is dependent on RAID levels. Distributed RAID can recover single disk failure while dual distributed RAID is recoverable from two disk failures.

Replacing such parts are very simple and most of the time you can perform the swapping on the fly. However always refer to the original manufacturer's document in case of any ambiguity. 

Make sure to read all supporting manuals and documentations before swapping/replacing any disk or other hot swap-able parts.
(PS: Not all parts in an Enterprise Storage are hot swap able)