Profile cover photo
Profile photo
Jérôme Carretero
Left brainer, right handed
Left brainer, right handed

Jérôme's posts

Caught up with the latest food brands M&A after seeing "Milka w/ Oreo" in the store yesterday.

Rant on the worst disk drive ever: #OCZ #Agility 3

When coming to work at #Tamaggo (2012) I've been spoiled with a beefy computer having default configuration with a mirror of these drives (plus a mirror of 1TB WD blacks).

On paper, the Agility 3 looked nice, a latest-generation cost-effective #SSD that's just a little slower than the best SSDs of that time when it comes to writes.

But soon enough we've discovered how painful the Agility can be. 
While we can still bear working with them, +Rejean Groleau experienced a scary data loss, almost every developer doing serious compilation ("alors les nerds, ça compile sec ?" comme dit +Jonathan Poitras)  got itself regularly with the following situation that we called "agilititis":
- activity suspended for seconds... to hours!
- writes are capped to 100 iops
- you basically cannot use your computer to do any disk I/O related task
Usually what we do is go take a coffee break when that happens...

That might not be specific to Agility 3 since googling "SSD 100 iops" leads to reports on other brands having SandForce controllers, but I don't care.
This is related to the poor TRIM/discard implementation in their firmwares.

Anyway, I haven't found a real solution, preventive actions such as keeping a lot of free space and running fstrim don't help a lot.

The lesson that I draw from this is to not get unproven work hardware, and stress-test the configurations. At the time, a single venerable intel SSD could have been a better choice. It's probably still the case today.

Regarding data loss, one very important thing is that nothing important should reside more than transiently on a developer's computer: all the production is to be duly checked in in SCM.
Also, installing the work environment should be fast.
But that's no reason to use flaky storage.

Side note: a dozen of dudes that run linux ( #Gentoo  or  #Ubuntu ) have been using #btrfs  partitions and while there were a few kernel panics in 2012, no bit was lost.

Dear Lazyweb,

I'm using both vim and emacs, and there is something that bothers me a bit in emacs, concerning "inotify" and interaction with SCM:

- How to have emacs prompt "just like vim" when a file is modified externally ? In vim, a dialog appears and prompt you to either ignore an external modification, or reload the file. In emacs, it's only when you're about to save the file, that the question is asked.

- How to have emacs ignore file modification events when the file has not changed? For example, if I'm doing a "git stash", "git stash pop", in the end, emacs will ask me if I really want to continue editing the file... but it should be smart enough to know that the question is moot!

TL;DR: Creating information is almost always part of an act of communication, and a piece of communication has a context, purposes, a source and recipients, a channel, production/consumption/storage/delivery costs, plus other constraints.
All of this will condition the form of the information, and it's usually wise to consider this when creating information you want 'optimized'.


I usually wake up reading my e-mails and going through slashdot, and today's events catalyzed this post.

First, while reading a discussion thread on  « Why Are We Still Writing Text-Based Code? » there was a funny quote (

  A picture is worth a thousand words.
  A thousand pictures flipping past at 24 frames per second is worth ten words.

The article is about usage of graphical languages (eg. Simulink, LabVIEW, ...), which are not completely foreign to me, but I won't even be talking about that (while they are cool, and can be adapted to some applications, my main grief is that the most widely used are nightmares in terms of SCM, scaling and vendor lock-in).

The second event is that I got a work e-mail from a QA colleague that was describing a problem by sending 2 iPhone camera shots of a phenomenon. I can't go in the details but these images were mostly useless: the phenomenon was not clear, the quality was low (uncropped, bad white balance, bad focus) and they had been hand-edited to include a text pointer (so, I estimate that it took at least one minute to create, transfer, edit and include these pictures in the e-mail). The e-mail was totalling 7.63 MB, so it took me a while to download it from home. A simple sentence would have been sufficient and clearer to describe this problem. Oh, and of course, the company has an IT system called an issue tracker to deal with this...

I have a serious problem not only with wasted bytes, but even more regarding valuable information that is not 'optimized': not concise, or using a lesser appropriate format.

Text has the nice habit of being very easily searchable, editable, it can be consolidated easily. Information in textual form is very convenient and forgiving. It's really hard to write a piece of text that is completely useless to the recipients (but it definitely does happen).

Pictures are helpful for an instant comprehension of a phenomenon, or can convey feelings, but unless they are art, they are mostly a liability unless temporary.
Generally pictures are quite costly because the amount of information per byte is quite low, but there are cases where it's hard to avoid them (I'm currently dealing with terabytes of raw photographic data in my job), and there are also exceptions.
Schemas (graphs, flowcharts, visualizations) are a specialized form of pictures which is usually quite useful, and compact.
Doing serious schema works will usually lead you to using programming languages to write the schema.
Looking back for information in a picture is costly.

Motion pictures, are in my opinion falling in the categories of either works of art, memories, or "temporary" (waiting to be consolidated in another format, or deleted).
Parenthesis: It's plaguing the internet and I really hate it when some important piece of technical information is only available in the middle of a video-recorded presentation, an ungrepable waste of both bytes and time. I find that borderline disrespectful for the audience. Of course, at some point we're all presentation newbies.

Whether you want to share information, make sense of data, do indexing or data archeology, you will find that introducing non-text data with text meta-data is useful, be it a pointer, an outline, a summary. Do that and it will pay off sooner than later.

Post has attachment
Dommage pour le sable dans le pare-brise, mais voici des videos du Tamaggo ibi dans une voiture du rallye Dakar!

Avouez que c'est du jamais vu! Payez mon salaire, achetez-en un: ;)

Post has attachment
Finalement, le voile est (partiellement) levé sur le produit sur lequel je travaille: le tamaggo ibi (, une camera panoramique "fish-eye".
La capture de photo/video panoramique peut sembler gadget maintenant, tout comme les ordinateurs de poche il y a quelques années ;)

Note: au 2014-01-06, le champ de vision sur l'application Flash du site web est réduit artificiellement; le fichier contient davantage.

Post has attachment
I haven't emerged from my cave yet.

Post has attachment
Easy money!
February 2, 2013
3 Photos - View album

Post has attachment
"Learn Linux the Hard Way", a web-based series of exercises with an interactive Linux prompt and explanations.

Post has attachment
Un "banc de poissons" à Badu, Taiwan.

Je ne pense pas qu'ils l'ont calulée, celle-là.
Wait while more posts are being loaded