31 Oct, 2009

My Ideal layered distributed clustered redundant self healing Filesystem

Posted by Bhavin Turakhia | (4) Comments

This is a collection of notes on the features that my dream filesystem would support -

• multi-Layered storage – ability to support layers of slower to faster disks and move data at block and/or file level between them atomically, keeping the most frequently read data on the fastest disks. If there is block level support for this it would be a boon for databases, where frequently accessed pages could be kept in faster SSDs and less frequently accessed pages would be stored on slower SATA drives
• Distributed – ability to have multiple clients participate and access a single virtual storage device
• Replicated – each file (or block) is replicated ‘n’ times using master-master sync/async replication
• No FSCK
• Self-healing
• Compression – native support for compression at file or block level (ideally the former)
  • Ability to access the file in its compressed form (useful where we can send out a compressed byte stream to the client and the uncompression is handled at the client)
• Snapshot capability
• Parity based RAID without write penalties (like Raid-Z)

ZFS supports many of the above features.

10 Oct, 2009

Judging Humility in an Interview

Posted by Bhavin Turakhia | (16) Comments

At Directi, one of the most important qualities we value in potential candidates is humility. Infact, in the constantly dynamic landscape that is our industry, the only way to keep up is to know that you don’t know [it all]. Infact I include humility as an important attribute in my document on Skills and attributes that a good developer must possess.

I never really got a handle on how one can judge humility of an individual, until it struck me recently. A technique that has actually effectively worked in the past, but I have never paid attention to it. Humble individuals are always respectful, and do not have an air about them. One of the ways I have been able to distinguish individuals who are not humble are those who feel specific interview questions are beneath them to answer. We have all seen this category. Often I will fire an extremely easy or fundamental or theoretical question in my interview to a candidate – and they will respond with a short answer – accompanied by negative body language or verbal cues or in some cases a direct rebuke that essentially states – “Are you kidding me? Why are you asking me such a question at my level. I am above this type of questioning.”

There are only two reasons (not mutually exclusive) for this type of a response – (1) Ignorance – the candidate does not know the answer to the question and instead of acknowledging it he prefers to go down the path of “this question is beneath me”, (2) Lack of Humility

At Directi -

• no question is ever beneath someone
• all of us know that we have a lot to learn
• none of us feel uncomfortable in acknowledging something we don’t know
• all of us are respectful

So if you want to judge the humility of an individual during an interview – ask a couple of really easy questions – and see how they respond

Do you feel you would fit into our work culture? Apply at http://careers.directi.com