Sunday, April 30, 2006

Storage Exam Questions 1: Disk Drive

It has been over four months since I wrote anything about storage certification. Previously, I mentioned websites of industry associations, standards organizations and companies that contain material helpful for exam preparation. Here are eight disk drive questions to help you prepare for certification exam:

1. What factors impact performance of disk drive?

A. Seek Time
B. Latency
C. Transfer Time
D. Array Cache

2. Which parameter is not part of internal addressing of disk drive?

A. Cylinder
B. Block
C. Head
D. Sector

3. Which function in a disk drive tries to anticipate the next data block being accessed by the user?

A. Sector
B. Buffer
C. Track
D. Head

4. What is Seek Time?

A. The time disk takes to move head to a particular track on the disk.
B. The time for disk to rotate to place the correct location under the head.
C. The time disk takes to fill the disk buffer memory.
D. The time taken by disk interface in carrying the data from disk.

5. What is true for a Head?

A. Information accessed without undertaking a seek operation.
B. Subdivision of a disk surface.
C. Used to define a single disk surface.
D. Controller overhead.

6. What is not true for a Buffer?

A. Memory
B. Holding space for data until written to surface
C. Located between disk interface and disk electronics.
D. Same size as a sector.

7. Which one in not part of formatting a disk?

A. Divide track into sectors.
B. Repair unusable sectors.
C. Find damaged sectors.
D. Flag bad sectors.

8. What parameter is part of external addressing of disk drive?

A. Block
B. Head
C. Cylinder
D. Buffer Credit

Previous certification related blog entries:

Storage Certification Material

Training Feedback

Backup Tutorial

Storage Training, Certification & Large Archive

And you most probably guessed it by now, I am quite busy with work that pays my bills. So, I haven't got around to reading or writing anything interesting but bear with me. In this business, busy times are followed by down time and vice-versa.

Monday, April 24, 2006

Calling iSCSI target software vendors

Since I wrote blog entries Who will be next? and WinTarget Alternatives, I am receiving steady flow of inquiries about iSCSI target software products available in the market.

I am compiling information on iSCSI target software products to write on this topic in future entries. If you have a software product in this space, get in touch with product information.

You may get some free publicity through this blog.

Wednesday, April 19, 2006

WinTarget Alternative

Yesterday, I received a query for alternatives to WinTarget product. Just to recap, WinTarget was an iSCSI target software for Windows platform developed by String Bean Software, acquired by Microsoft (See Who will be next?).

The request reminded me of an email, I received from a competitor, soon after WinTarget acquisition by Microsoft. In general, such communications after an M&A event target customers and partners to create FUD aka fear to make them switch. I wonder do these fear based communications after an M&A really work! I usually ignore such messages.

But this specific email was polite and not based on fear. I think it deserves a mention here to help people searching for alternatives to WinTarget.
Subject: Rocket Division Software cooperation offer.
From: "Artem A. Berman"
Date: Fri, Mar 10, 2006 6:25 am


We've noticed that your company is mentioned on String Bean Software site as their partner. After acquisition of SBS by Microsoft and with WinTarget leaving the market we thought it would be ethical to contact you and propose the cooperation

Rocket Division Software is iSCSI and AoE software storage solutions vendor. We would be happy to provide you with complete information about our company and software we offer per your request.

We're looking forward to do mutually beneficial business with you. Thank you for taking the time reading this message.

Artem A. Berman

I don't know the product, the organization or the people behind the organization, so I can't vouch for these guys. As always, please do your own due diligence.

Monday, April 17, 2006

Storage meets Wiki misses Eyeballs

Yesterday, Jeremiah O., the brain behind HDS blogs initiative, sent me a message mentioning his storage blogroll. He also posted this information in a comment to my post about David Merrill blog.

So here is plug for his storage blogroll one more time. Access it through his virtualized URL And in case his virtualization vendor drops off the earth, here is the un-virtualized version of blogroll URL ;-)

Also, check out Mario Apicella wondering about small world of storage bloggers in his post Why are storage folks not blogging?. He makes a very good point from customer perspective in response to my comment about low potential of wider readership of storage blogs:
The reality is that purchasing storage often generates transactions that are several orders of magnitude more expensive than buying new servers, for example. People may not look at storage very often but when they do they are in for big money and need good advice.
Here is my 'role-reversal' comment from vendor perspective. Potentially large cash inflow per deal encourages storage vendors to put muzzle on their employees ... impact of losing and wining a deal on bottom line is significant enough to discourage free flow of information from rank-and-files. Instead storage blogging is mostly restricted to vendors' upper echelon (See, my post from last year on related topic Does Blogging belong to Upper Echelon only?).

If people are not going to look at storage very often, they are not going to read about it often either resulting in fewer eyeballs for storage blogs.

Sunday, April 16, 2006

Gatekeepers Babysitters Datacenters

For the past few weeks, I wasn't able to post regularly due to a very hectic schedule. So I am trying to write a series of quick short catchup posts summarizing the things I have been working on, thinking, reading and researching about. No indepth analysis, here. This is the first in this series:

In last couple of weeks, I visited about a dozen datacenters. What I noticed most is the inefficiencies, in the name of security, at datacenters for both services provider personnel and datacenter employees! During each visit, I spent 15 to 30 minutes going through the gatekeeper's entry procedures and datacenter employees spent two to four hours babysitting me while I was inside the datacenter. That is some serious productivity loss for both service providers and datacenter owners.

Another thing, I observed is the lack of security cameras inside the datacenters. Security cameras were everywhere outside and inside the buildings except in datacenters!

Aren't there better ways to handle gatekeeping and babysitting work at datacenters?

Monday, April 10, 2006

HDS TCO/ROI Guru starts Blogging

Today, I read in Hu Yoshida's blog entry that David Merrill has decided to join blogosphere community.

For last few years, I have extensively used ideas from his Storage ROI/TCO work in building business cases for storage technologies. Typically, vendor white papers have limited lifespan and focus on specific products. In my opinion, this is not the case with his work. With the longevity and usefulness of his ROI/TCO white papers, I sometime wonder how come he hasn't thought about writing a book on Economics of Storage.

If you are involved on business side of storage technologies, you may want to read his ROI/TCO work. It is time well wasted, comedy central style!

Welcome David, I am looking forward to reading your thoughts on storage economics. And considering how many HDS people are now blogging, may be you and Jeremiah want to collaborate on a case study for ROI of corporate blogs.